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		<title>F1000 Research—yet another open-access publisher</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/30/f1000-research-yet-another-open-access-publisher/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/30/f1000-research-yet-another-open-access-publisher/#comments</comments>
		<pubDate>Tue, 31 Jan 2012 05:38:00 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[academic publishing]]></category>
		<category><![CDATA[arXiv]]></category>
		<category><![CDATA[F1000]]></category>
		<category><![CDATA[Faculty of 1000]]></category>
		<category><![CDATA[open access]]></category>
		<category><![CDATA[peer review]]></category>
		<category><![CDATA[vanity press]]></category>

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		<description><![CDATA[F1000, who publish the extremely pricey &#8220;Faculty of 1000&#8243; reviews of scientific literature are now throwing their hat in the open-access publication ring with F1000 Research. They are planning to do post-publication review,which is the current darling of the open-access advocates, as it pretty much guarantees that anything someone wants to publish will appear—the only [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3505&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>F1000, who publish the extremely pricey &#8220;Faculty of 1000&#8243; reviews of scientific literature are now throwing their hat in the open-access publication ring with <a href="http://f1000research.com/">F1000 Research</a>.</p>
<p>They are planning to do post-publication review,which is the current darling of the open-access advocates, as it pretty much guarantees that anything someone wants to publish will appear—the only barrier being the price the author has to pay to get it published. F1000 has been doing post-publication review (of work from any scientific journal) for years, so they have some ideas about how that should go.</p>
<p>I&#8217;ve written some Faculty of 1000 reviews, and I found their editorial constraints rather limiting.  They never wanted any negative comments about a paper, just superlatives.  Even the very good papers I read generally had a few flaws, and they kept wanting to remove mention of those parts from my reviews.  I&#8217;ve pretty much given up doing reviews for Faculty of 1000 for several reasons:</p>
<ul>
<li>Their subscription prices are so high that the University of California Library has come close to unsubscribing a couple of times, and I don&#8217;t want to be providing free content to a company then charging so much for the content.</li>
<li>Their editorial policy of &#8220;superlatives only&#8221; does not match my more balanced (or perhaps just more negative) reviewing style.</li>
<li>I&#8217;ve lost interest in the field for which the originally recruited me. I find it very difficult these days to read most papers on protein structure prediction and related fields.  Mostly people are rehashing ideas that have been around for a decade or more, rarely improving on them.  There are probably only a handful of good papers a year in the field, and I don&#8217;t have the patience to find them.  (That is the job of F1000 reviewers, and if I were eagerly reading dozens of papers I&#8217;d be glad to share the occasional gem, but I&#8217;m not eagerly reading papers, so I almost never encounter the good ones.)</li>
</ul>
<p>Given F1000&#8242;s history, I&#8217;m worried that the new F1000 Research will be very expensive and will quickly become a repository for trash papers. In a standard open-access journal that problem can be avoided with strong editorial control (<a href="http://www.ploscompbiol.org/">PLoS Computational Biology</a> generally publishes decent papers, for example), but with only post-publication review, the venue is likely to get clogged with stuff too bad to be published elsewhere.</p>
<p>Who is going to want to do post-publication review of a stream of junk?  It is hard enough reading the mediocre papers that have already been through peer review already—reading the ones that even the authors think would fail peer review would be excruciating.  If no one competent is reading and critiquing the papers, then the junk will not be filtered out and the whole process will degrade into a vanity press.  There are already dozens of vanity open-access journals that will print any sort of s**t if the author pays the fee (even going through a pretense of peer reviewing), and I did not see anything in the F1000 Research announcement that suggested that they would avoid this trap.</p>
<p>Note that what F1000 is proposing is very different from the open access in <a href="http://arxiv.org/">arXiv</a>, the (mostly) pre-publication archive heavily used by the physics community. &#8220;Open access to 731,853 e-prints in Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics.&#8221;  The arXiv site does not provide discussion forums, but many researchers put papers into arXiv for pre-publication discussion before submitting them to peer-reviewed journals.  There are enough respected scientists doing this that people do regularly look through arXiv for interesting material in their field. Because depositing a paper in arXiv gets it read by a few people, but does not count as publication for promotion and tenure, there is little incentive to clog arXiv with junk.</p>
<p>People do sometimes stick papers in there to establish that they got an idea first, even if the paper needs some work still before it is publishable, and sometimes the early drafts of a paper have flaws that are revealed before publication, but most of the papers in arXiv are published in peer-reviewed journals eventually.</p>
<p>Also, note that the fields most rife with sloppy research and outright fraud are not covered by arXiv (medical research seems to have the lion&#8217;s share of scientific fraud, probably because of the amount of money involved). Although there are some crackpot papers in arXiv, for the most part it is real science. I believe that F1000 wants to cover a wider swath, including fields in which fraud and crackpot theorists are a more common problem.  Relying on post-publication review seems a risky endeavor.</p>
<p>Disclaimer: as an unfunded researcher, I have mixed feelings about open-access publication. I like getting papers for free, and I like the idea of distributing scientific papers as freely and cheaply as possible. But most of the business models call for the author to pay for publication, which is fine for those who have grants that can pay publication charges, but deadly for those of us without funding.  Open-access publishing may, in fact, restrict publishing to a smaller group of authors than the traditional publication model—those with money.  Requiring those with grants to publish in open-access venues makes some sense to me as a taxpayer, but if it results in the loss of subscriber-pays journals, many researchers will be excluded from publication, and everyone will need to spend even more time writing grant proposals instead of doing research.</p>
<p>What I&#8217;d like to see are more things like arXiv, which provide free access funded neither by the authors nor the readers, but by organizations with an interest in free distribution of scientific literature (granting agencies, governments, and research libraries, for example).  I doubt that F1000, as a for-profit company, plans anything like that.</p>
<h6 class="zemanta-related-title" style="font-size:1em;">Related articles</h6>
<ul class="zemanta-article-ul">
<li class="zemanta-article-ul-li"><a href="http://johncarlosbaez.wordpress.com/2012/01/31/the-faculty-of-1000/">The Faculty of 1000</a> (johncarlosbaez.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://blogs.nature.com/news/2012/01/f1000-launches-fast-open-science-publishing-for-biology-and-medicine.html">F1000 launches fast, open science publishing for biology and medicine</a> (blogs.nature.com)</li>
<li class="zemanta-article-ul-li"><a href="http://rrresearch.fieldofscience.com/2012/01/arxiv-submission.html">ArXiv submission?</a> (rrresearch.fieldofscience.com)</li>
<li class="zemanta-article-ul-li"><a href="http://boingboing.net/2011/10/31/faster-than-light-neutrino-update-whats-going-on-behind-the-scenes.html">Faster-than-light neutrino update: What&#8217;s going on behind the scenes?</a> (boingboing.net)</li>
<li class="zemanta-article-ul-li"><a href="http://michaelnielsen.org/blog/on-elsevier/">On Elsevier</a> (michaelnielsen.org)</li>
</ul>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/academic-publishing/'>academic publishing</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/arxiv/'>arXiv</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/f1000/'>F1000</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/faculty-of-1000/'>Faculty of 1000</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/open-access/'>open access</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/peer-review/'>peer review</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/vanity-press/'>vanity press</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3505/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3505/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3505/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3505/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3505/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3505/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3505/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3505/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3505&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Magnetometer and accelerometer read simultaneously</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/30/magnetometer-and-accelerometer-read-simultaneously/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/30/magnetometer-and-accelerometer-read-simultaneously/#comments</comments>
		<pubDate>Tue, 31 Jan 2012 00:41:07 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[accelerometer]]></category>
		<category><![CDATA[Arduino]]></category>
		<category><![CDATA[I²C]]></category>
		<category><![CDATA[magnetometer]]></category>
		<category><![CDATA[robotics]]></category>
		<category><![CDATA[SparkFun]]></category>
		<category><![CDATA[SparkFun Electronics]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3427</guid>
		<description><![CDATA[In Learning to Use I2C and Magnetometer not fried, I talked about interfacing the MAG3110 magnetometer and MQA8452Q accelerometer to an Arduino.  For both, I&#8217;m using breakout boards from Sparkfun Electronics. I  checked today that there are no problems when I connect both devices to the same I2C bus. The first test was very simple: [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3427&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In <a title="Learning to use I2C" href="http://gasstationwithoutpumps.wordpress.com/2012/01/22/learning-to-use-i2c/">Learning to Use I2C</a> and <a title="Magnetometer was not fried" href="http://gasstationwithoutpumps.wordpress.com/2012/01/29/magnetometer-was-not-fried/">Magnetometer not fried</a>, I talked about interfacing the MAG3110 magnetometer and MQA8452Q accelerometer to an <a class="zem_slink" title="Arduino" href="http://arduino.cc" rel="homepage">Arduino</a>.  For both, I&#8217;m using breakout boards from <a class="zem_slink" title="SparkFun Electronics" href="http://www.sparkfun.com/" rel="homepage">Sparkfun Electronics</a>.<a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/magnetometer_accelerometer.jpg"><img class="alignright size-full wp-image-3428" title="magnetometer_accelerometer" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/magnetometer_accelerometer.jpg" alt="" width="600" height="400" /></a></p>
<p>I  checked today that there are no problems when I connect both devices to the same I<sup>2</sup>C bus.</p>
<p>The first test was very simple: I put both the breakout boards into a breadboard and wired them together, then tried running each of the programs I&#8217;d written for the chips separately. Result: no problems—worked first time.</p>
<p>I then tried merging the programs (cleaning up any naming conflicts) so that both could be run from the same code.  After a few typo fixes, this also worked fine</p>
<p>I think I&#8217;m now ready to hand over the software to the students to use for their robot.</p>
<p>I still need to put the i2c.h, i2c.cpp, and accel_magnet code in some public place for others to use (perhaps on github? maybe on my web pages at work?)</p>
<p>One thing that is still missing is doing tilt correction for the compass heading.  Since the ROV is not expected to remain level (the accelerometer is intended to be used in a feedback loop to adjust the pitch, with anything from -90° to +90° being reasonable), getting a good compass heading requires rotating the magnetometer readings into the horizontal plane.  Only one of the students in the robotics club has had trigonometry or matrix math, so I&#8217;ll have to work with him to get him to figure out how to do the tilt correction. It may be simplest conceptually  to compute pitch and roll angles first, then rotate twice, rather than trying to do the whole tilt correction in one step (especially since the Arduino does not have matrix libraries).</p>
<h6 class="zemanta-related-title" style="font-size:1em;">Related articles</h6>
<ul class="zemanta-article-ul">
<li class="zemanta-article-ul-li"><a href="http://gasstationwithoutpumps.wordpress.com/2012/01/22/learning-to-use-i2c/">Learning to use I2C</a> (gasstationwithoutpumps.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://gasstationwithoutpumps.wordpress.com/2012/01/20/soldering-problems/">Soldering problems</a> (gasstationwithoutpumps.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://gasstationwithoutpumps.wordpress.com/2012/01/29/magnetometer-was-not-fried/">Magnetometer was not fried</a> (gasstationwithoutpumps.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://hackaday.com/2011/10/25/tilt-compensation-when-reading-a-digital-compass/">Tilt compensation when reading a digital compass</a> (hackaday.com)</li>
</ul>
<p>&nbsp;</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/accelerometer/'>accelerometer</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/arduino/'>Arduino</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/i%c2%b2c/'>I²C</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/magnetometer/'>magnetometer</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/robotics/'>robotics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun/'>SparkFun</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun-electronics/'>SparkFun Electronics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3427/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3427/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3427/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3427/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3427/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3427/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3427/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3427/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3427&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Magnetometer was not fried</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/29/magnetometer-was-not-fried/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/29/magnetometer-was-not-fried/#comments</comments>
		<pubDate>Sun, 29 Jan 2012 21:12:20 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[accelerometer]]></category>
		<category><![CDATA[Arduino]]></category>
		<category><![CDATA[i2c]]></category>
		<category><![CDATA[magnetometer]]></category>
		<category><![CDATA[robotics]]></category>
		<category><![CDATA[SparkFun]]></category>
		<category><![CDATA[SparkFun Electronics]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3421</guid>
		<description><![CDATA[In Learning to Use I2C, I talked about the difficulty I&#8217;d been having getting the MAG3110 breakout board from Sparkfun to work, and my fears that I had burned it out by running it overnight at 5v (instead of the rated 3v).  I suspected that my problem was really a software problem, but debugging the [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3421&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<div class="wp-caption alignright" style="width: 198px"><a href="http://www.sparkfun.com/products/10619"><img title="MAG3110 breakout board by Sparkfun" src="http://dlnmh9ip6v2uc.cloudfront.net/images/products/10619-01_i_ma.jpg" alt="" width="188" height="188" /></a><p class="wp-caption-text">MAG3110 breakout board by Sparkfun</p></div>
<p>In <a title="Learning to use I2C" href="http://gasstationwithoutpumps.wordpress.com/2012/01/22/learning-to-use-i2c/">Learning to Use I2C</a>, I talked about the difficulty I&#8217;d been having getting the <a href="http://www.sparkfun.com/products/10619">MAG3110 breakout board from Sparkfun</a> to work, and my fears that I had burned it out by running it overnight at 5v (instead of the rated 3v).  I suspected that my problem was really a software problem, but debugging the software when I was afraid that the hardware was fried seemed like an exercise in futility.</p>
<p>I bought another of the breakout boards from Sparkfun (they&#8217;re only $15), and soldered on a header yesterday.  The code failed in almost exactly the same way with the new (presumed good) part as with the old (presumed fried) part, so I was convinced that the problem was indeed in the software.</p>
<p>I spent half of yesterday and most of this morning carefully rewriting the library of I<sup>2</sup>C interface code.  I was starting with <a href="http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Sensors/Accelerometers/MMA8452Q_Example.zip"> example code from Sparkfun for the MMA8452Q accelerometer</a>, which I had generalized to handle other I<sup>2</sup>C devices.</p>
<p>The library worked fine with the accelerometer, so I thought it was ok, but it did not work with the magnetometer. I added a lot of error checking (making sure that the microprocessor was in the expected state after each I<sup>2</sup>C operation), and found that things were not working as expected. The extra error checking made it much easier to diagnose the problems. I had to re-read the I<sup>2</sup>C documentation in the <a href="http://atmel.com/dyn/resources/prod_documents/8271S.pdf">ATMega328 datasheet</a> several times, to make sure that I had all the details right (I didn&#8217;t, of course). The documentation in that data sheet is better than several of the tutorials I&#8217;ve seen on line, and is both thorough and comprehensible in describing the interface.</p>
<p>I did not implement all features of the I<sup>2</sup>C  interface—in fact, I have a rather minimal implementation that uses polling rather than interrupts and assumes that the <a class="zem_slink" title="Arduino" href="http://arduino.cc" rel="homepage">Arduino</a> will always be the bus master.  Those assumptions are fine for most Arduino projects, which just use the I<sup>2</sup>C bus for talking to a handful of peripherals, but sometime in the future I may need to make a more complete set of code that can handle multiple masters, the Arduino as a slave device, and interrupts rather than polling and waiting for operations to finish.</p>
<p>Because I was more interested in simplicity and robustness than speed, I rewrote the code so that transactions were finished (and appropriate status checked) before functions returned.  With these changes I found that the STOP condition was not happening, despite being requested.  All other operations on the bus are checked with the TWINT bit  of the TWCR register and the upper bits of the TWSR register, but determining that STOP has completed requires checking the TSWTO bit of the TWCR register. The code I had started from just checked the TWINT bit for the other operations, and had a fixed timeout that was too short—it did no checking at all on the STOP state, just adding a fixed delay.</p>
<p>Once I got the STOP timing cleaned up (and earlier, making sure to send NAK when reading the last byte), everything worked fine.  The accelerometer code  had probably worked ok because there were enough delays after stops that the stops completed, even though I had not checked to make sure.  With the fixed code, even the magnetometer that I thought I had fried seems to work ok.</p>
<p>The interface for the students in the Robotics Club is fairly simple (much simpler than the standard &#8220;Wire&#8221; library):</p>
<p><pre class="brush: cpp;">
// Read one register
uint8_t i2cReadRegister(uint8_t i2c_7bit_address, uint8_t address);
// Read num_to_read registers starting at address
void i2cReadRegisters(uint8_t i2c_7bit_address, uint8_t address, uint8_t num_to_read, uint8_t * dest);

// Write one register
void i2cWriteRegister(uint8_t i2c_7bit_address, uint8_t address, uint8_t data);
// Write num_to_write registers, starting at address
void i2cWriteRegisters(uint8_t i2c_7bit_address, uint8_t address, uint8_t num_to_write, const uint8_t *data);
</pre></p>
<p>I suppose I should check that there are no problems when I connect both devices to the same I<sup>2</sup>C bus, before handing this over to the students to use for their robot.</p>
<p>I should also put the i2c.h and i2c.cpp in some public place for others to use (perhaps on github? maybe on my web pages at work?). It is really a shame that WordPress.com does not permit code-like files as pages.</p>
<h6 class="zemanta-related-title" style="font-size:1em;">Related articles</h6>
<ul class="zemanta-article-ul">
<li class="zemanta-article-ul-li"><a href="http://gasstationwithoutpumps.wordpress.com/2012/01/22/learning-to-use-i2c/">Learning to use I2C</a> (gasstationwithoutpumps.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://gasstationwithoutpumps.wordpress.com/2012/01/20/soldering-problems/">Soldering problems</a> (gasstationwithoutpumps.wordpress.com)</li>
</ul>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/accelerometer/'>accelerometer</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/arduino/'>Arduino</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/i2c/'>i2c</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/magnetometer/'>magnetometer</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/robotics/'>robotics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun/'>SparkFun</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun-electronics/'>SparkFun Electronics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3421/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3421/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3421/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3421/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3421/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3421/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3421/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3421/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3421&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Physics homework for chapter 6</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/28/physics-homework-for-chapter-6/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/28/physics-homework-for-chapter-6/#comments</comments>
		<pubDate>Sat, 28 Jan 2012 18:56:14 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[energy]]></category>
		<category><![CDATA[physics]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3418</guid>
		<description><![CDATA[For Chapter 6 of Matter and Interactions, we should do the following problems: 6.P.54, 6.P.61, 6.P.66, 6.P.71, 6.P.81, 6.P.87, 6.P.95, 6.P.98, 6.P.100, 6.P.105, 6.P.107, 6.P.108 Tagged: energy, physics<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3418&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>For Chapter 6 of Matter and Interactions, we should do the following problems:</p>
<p>6.P.54, 6.P.61, 6.P.66, 6.P.71, 6.P.81, 6.P.87, 6.P.95, 6.P.98, 6.P.100, 6.P.105, 6.P.107, 6.P.108</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/energy/'>energy</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/physics/'>physics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3418/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3418/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3418/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3418/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3418/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3418/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3418/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3418/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3418&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Another plea for physics lab ideas</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/27/another-plea-for-physics-lab-ideas/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/27/another-plea-for-physics-lab-ideas/#comments</comments>
		<pubDate>Sat, 28 Jan 2012 00:40:07 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[energy]]></category>
		<category><![CDATA[high school]]></category>
		<category><![CDATA[physics]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3412</guid>
		<description><![CDATA[I&#8217;m having trouble coming up with any sort of meaningful lab for Chapter 6 of Matter and Interactions.  This is the first chapter on energy, introducing it as and discussing potential and kinetic energy.  There is a fair amount of math we can do (like deriving the formula for energy from  ), and plenty of [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3412&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>I&#8217;m having trouble coming up with any sort of meaningful lab for Chapter 6 of <a href="http://matterandinteractions.org/">Matter and Interactions</a>.  This is the first chapter on energy, introducing it as <img src='http://s0.wp.com/latex.php?latex=E%3D+%5Cgamma+m+c%5E2&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='E= &#92;gamma m c^2' title='E= &#92;gamma m c^2' class='latex' /> and discussing potential and kinetic energy.  There is a fair amount of math we can do (like deriving the formula for energy from  <img src='http://s0.wp.com/latex.php?latex=dE%2Fdx+%3D+F%3D+dp_x%2Fdt&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='dE/dx = F= dp_x/dt' title='dE/dx = F= dp_x/dt' class='latex' />), and plenty of calculations, but I don&#8217;t see any easy labs.  Labs become fairly easy again in Chapter 7, but I&#8217;d welcome any suggestions for things we could do with equipment I could build in the next few days.  (I have to keep the pace at a chapter every two weeks if we&#8217;re going to finish the mechanics part of the book before the AP exams.)</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/energy/'>energy</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/high-school/'>high school</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/physics/'>physics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3412/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3412/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3412/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3412/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3412/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3412/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3412/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3412/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3412&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Another success for FoldIt</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/25/another-success-for-foldit/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/25/another-success-for-foldit/#comments</comments>
		<pubDate>Thu, 26 Jan 2012 04:20:00 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[David Baker]]></category>
		<category><![CDATA[FoldIt]]></category>
		<category><![CDATA[protein engineering]]></category>
		<category><![CDATA[protein folding]]></category>
		<category><![CDATA[protein structure]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3409</guid>
		<description><![CDATA[David Baker&#8216;s group has had another success for FoldIt, their computer game for folding proteins.  As reported in Nature News, Victory for crowdsourced biomolecule design, FoldIt players managed to improve the computer-designed enzyme that catalyzes Diels-Alder reactions.  I&#8217;ve not read the paper itself (Increased Diels-Alderase activity through backbone remodeling guided by FoldIt players), which is [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3409&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p><a class="zem_slink" title="David Baker (biochemist)" href="http://en.wikipedia.org/wiki/David_Baker_%28biochemist%29" rel="wikipedia">David Baker</a>&#8216;s group has had another success for <a href="http://fold.it">FoldIt</a>, their computer game for folding proteins.  As reported in Nature News, <a href="http://www.nature.com/news/victory-for-crowdsourced-biomolecule-design-1.9872">Victory for crowdsourced biomolecule design</a>, FoldIt players managed to improve the computer-designed enzyme that catalyzes Diels-Alder reactions.  I&#8217;ve not read the paper itself (<a href="http://www.nature.com/nbt/journal/vaop/ncurrent/full/nbt.2109.html">Increased Diels-Alderase activity through backbone remodeling guided by FoldIt players</a>), which is hidden behind a paywall (though UC has a library subscription, so I do have access).</p>
<p>The initial impressive feat from Baker&#8217;s group was that they designed an enzyme de novo using Rosetta design (this was reported in 2010).  The FoldIt addition was an 18-fold increase in activity, which came from targeted redesign (redesigning a loop to increase contact between the protein and one of the reactants, stabilizing the new loop, and so forth).  The FoldIt players were not not choosing the goals of the redesign (that was done by postdocs in Baker&#8217;s group), but they were exploring the protein space in ways that conventional optimization programs do not (such as adding 13 amino acids).</p>
<p>This is not the first success for FoldIt.  They had a <a href="http://www.nature.com/nature/journal/v466/n7307/full/nature09304.html">Nature paper in 2010</a>, which reported on the success of FoldIt players at predicting protein structure on a target that had eluded automatic methods for a few years.</p>
<p>So far as I know, FoldIt is the only computer game so far to have made any real advances in molecular engineering. (The main other contender, <a title="EteRNA, an Online Game" href="http://gasstationwithoutpumps.wordpress.com/2011/01/12/eterna-an-online-game/">EteRNA</a>, though fun to play, does not capture enough in its scoring function for EteRNA play to do anything very useful.)</p>
<p>Disclaimer: my former PhD student, Firas Khatib, was an author on both the FoldIt papers mentioned here, though he was not part of the original enzyme design team.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/david-baker/'>David Baker</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/foldit/'>FoldIt</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/protein-engineering/'>protein engineering</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/protein-folding/'>protein folding</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/protein-structure/'>protein structure</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3409/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3409/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3409/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3409/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3409/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3409/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3409/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3409/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3409&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Arsenic-based life was bogus</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/24/arsenic-based-life-was-bogus/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/24/arsenic-based-life-was-bogus/#comments</comments>
		<pubDate>Wed, 25 Jan 2012 03:05:05 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[arsenic]]></category>
		<category><![CDATA[Felisa Wolfe-Simon]]></category>
		<category><![CDATA[GFAJ-1]]></category>
		<category><![CDATA[Rosie Redfield]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3406</guid>
		<description><![CDATA[For those who have been following the news about the surprising claim by Felisa Wolfe-Simon that a bacterium isolated from Mono Lake incorporated arsenate into its DNA backbone in place of phosphate, there seems to be some pretty strong refutation of the claims now.  (I blogged about it twice before: when the story first came [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3406&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>For those who have been following the news about the surprising claim by Felisa Wolfe-Simon that a bacterium isolated from Mono Lake incorporated arsenate into its DNA backbone in place of phosphate, there seems to be some pretty strong refutation of the claims now.  (I blogged about it twice before: <a title="bacterium that uses arsenate in place of phosphate" href="http://gasstationwithoutpumps.wordpress.com/2010/12/05/bacterium-that-uses-arsenate-in-place-of-phosphate/">when the story first came out</a> and <a title="Followup on “arsenic life”" href="http://gasstationwithoutpumps.wordpress.com/2011/08/13/followup-on-arsenic-life/">later</a> when the experimental refutations were beginning to come out.)</p>
<p>Rosie Redfield have openly posted data using better lab procedures that show no arsenic in the DNA. The <a href="http://rrresearch.fieldofscience.com/2012/01/growth-of-gfaj-1-under-phosphate.html">latest post in the series</a> addresses some incorrect assertions about Dr. Redfield&#8217;s protocols that appeared in the Nature News article<a href="http://www.nature.com/news/study-challenges-existence-of-arsenic-based-life-1.9861"> Study challenges existence of arsenic-based life</a>.</p>
<p>With this new data, the burden is clearly on Dr. Wolfe-Simon to either retract her paper or provide some more convincing evidence for her astonishing claim.  I am doubtful that <em>Science</em> will put any pressure on her to retract, since they have a long history of presenting sensational, but wrong, science papers.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/arsenic/'>arsenic</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/felisa-wolfe-simon/'>Felisa Wolfe-Simon</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/gfaj-1/'>GFAJ-1</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/rosie-redfield/'>Rosie Redfield</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3406/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3406/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3406/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3406/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3406/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3406/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3406/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3406/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3406&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Learning to use I2C</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/22/learning-to-use-i2c/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/22/learning-to-use-i2c/#comments</comments>
		<pubDate>Mon, 23 Jan 2012 03:34:40 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[accelerometer]]></category>
		<category><![CDATA[Adafruit Industries]]></category>
		<category><![CDATA[Arduino]]></category>
		<category><![CDATA[magnetometer]]></category>
		<category><![CDATA[robotics]]></category>
		<category><![CDATA[SparkFun]]></category>
		<category><![CDATA[SparkFun Electronics]]></category>

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		<description><![CDATA[For the Santa Cruz Robotics Club, I&#8217;ve bought three sensors for their underwater ROV: a magnetometer, an accelerometer, and a pressure sensor. Originally, we were going to an ADXL335 accelerometer (with a breakout board by Adafruit Industries) and an MPXHZ6250A pressure sensor (no magnetometer), for which I designed a small PC board, but once the [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3400&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>For the Santa Cruz Robotics Club, I&#8217;ve bought three sensors for their underwater ROV: a magnetometer, an accelerometer, and a pressure sensor.</p>
<p>Originally, we were going to an ADXL335 accelerometer (with a <a href="http://www.adafruit.com/products/163">breakout board by Adafruit Industries</a>) and an <a href="http://www.freescale.com/webapp/sps/site/prod_summary.jsp?code=MPXx6250">MPXHZ6250A</a> pressure sensor (no magnetometer), for which I designed a small PC board, but once the <a href="http://www.materover.org/rov_competition_files/2012/2012_COMPETITION_MISSIONS_FINAL.pdf">specs for this year&#8217;s mission</a> came out, we saw that they wanted us to determine compass headings for a &#8220;sunken ship&#8221;, so it seemed a natural thing to add a magnetometer to the hardware.  After looking at what was available, I chose the <a href="http://www.sparkfun.com/products/10619">MAG3110 breakout board from Sparkfun</a>, because it provided a triple-axis magnetometer for only $15.</p>
<p>The MAG3110 is an I<sup>2</sup>C interface, which means we need only 2 wires to hook it up (and the wires can be shared with other I<sup>2</sup>C devices).  If we are going to all the trouble of figuring out an I<sup>2</sup>C interface, I figured we might as well use it for the accelerometer as well, so I got a <a href="http://www.sparkfun.com/products/10953">MMA8452Q breakout board from Sparkfun</a> also.</p>
<p>I decided to do a simple test program for the I<sup>2</sup>C parts before handing them over to the robotics club, so that they could be sure they had working parts.  It was a good thing I did, because I spent more than an entire day trying to get the parts to work.  I finally gave up on the &#8220;Wire&#8221; library from the Arduino website, and tried using the i2c.h file from Sparkfun (example code linked to from the accelerometer web page).  I got that working and rewrote the library as a proper .h and .cpp file, so that it could be installed as a normal Arduino library, adding some of the utility calls that had been buried in the MMA8452 demo code.</p>
<p>The MMA8452Q code was working fine, so I tried using the same i2c library for the MAG3110 magnetometer.</p>
<p>I had gotten MAG3110 working with the Wire library, but running at 5v (I&#8217;d not noticed that it was a 3.3v part—rather, I thought I&#8217;d checked that it was a 5v part, but I was wrong).  I&#8217;d left it powered at 5v all night, and I think I burned it out, as it was quite warm in the morning.  Today, I can read and write the registers of the MAG3110, but the xyz values are not coming out reasonable at all—I frequently get the same values (like 0xF9F9)and 0x1DF9), independent of the orientation. If I read all the registers, a lot of them come out as 0xF9 or 0x1D.  Even the WHO_AM_I register (which should be 0xC4) often comes out 0x1D.  I seem to get intermittent correct values for registers, but mostly bogus values.</p>
<p>I&#8217;ll feel stupid if I order another part and it turns out to be a software bug, but I&#8217;m pretty sure the chip is fried.  But I guess it is time to do another Sparkfun order. (I owe them some business, after <a title="Soldering problems" href="http://gasstationwithoutpumps.wordpress.com/2012/01/20/soldering-problems/">calling them for the replacement photointerrupter</a>.)</p>
<p>Incidentally, I tried finding a usable pressure sensor with an I<sup>2</sup>C interface, but it doesn&#8217;t look like anyone is making them except for barometric pressure ranges for dry gases.  I suppose Freescale will eventually come out with a full range of I<sup>2</sup>C pressure sensors, but my guess is that will be a long time coming, as the automotive and industrial applications have a pretty long product design cycle (unlike consumer electronics, which is driving the barometric pressure sensors).</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/accelerometer/'>accelerometer</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/adafruit-industries/'>Adafruit Industries</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/arduino/'>Arduino</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/magnetometer/'>magnetometer</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/robotics/'>robotics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun/'>SparkFun</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun-electronics/'>SparkFun Electronics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3400/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3400/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3400/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3400/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3400/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3400/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3400/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3400/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3400&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Soldering problems</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/20/soldering-problems/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/20/soldering-problems/#comments</comments>
		<pubDate>Sat, 21 Jan 2012 04:29:21 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[photogate]]></category>
		<category><![CDATA[soldering]]></category>
		<category><![CDATA[SparkFun]]></category>
		<category><![CDATA[SparkFun Electronics]]></category>

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		<description><![CDATA[In Newton&#8217;s measurement of g, I said &#8220;In preparation for this, I had bought a “photo interrupter” from Sparkfun and a breakout board to mount it. (Actually, I ordered 2, which was a good thing, since one of them did not work—Sparkfun is sending me a replacement).&#8221; I think I owe Sparkfun a couple of [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3397&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In <a title="Newton’s measurement of g" href="http://gasstationwithoutpumps.wordpress.com/2012/01/13/newtons-measurement-of-g/">Newton&#8217;s measurement of g</a>, I said <em>&#8220;In preparation for this, I had bought a “<a href="http://www.sparkfun.com/products/9299">photo interrupter</a>” from <a title="SparkFun Electronics" href="http://www.sparkfun.com/commerce/categories.php" rel="homepage">Sparkfun</a> and a breakout board to mount it. (Actually, I ordered 2, which was a good thing, since one of them did not work—Sparkfun is sending me a replacement).&#8221;</em></p>
<p>I think I owe Sparkfun a couple of bucks for that replacement, because I now no longer believe that the part was faulty.</p>
<p>The replacement part arrived yesterday, so this morning I unsoldered the part that I believed was faulty and put in the new one.  Getting the holes clear enough to insert the new part was a bit difficult with just a soldering iron and a solder sucker, but I eventually managed to do it.  Since I already had the good photogate set up for the physics lab, I did not get a chance to test the spare until after lab was over.  It didn&#8217;t work either!</p>
<p>Now, I&#8217;m willing to believe in one random part failing, but two in a row seemed unlikely.  That lead me to suspect problems with either the soldering or with the breakout board.I had already checked thoroughly for shorts (I always do that before powering up a board), and I knew there were none.</p>
<p>I had noticed when taking pictures of the photogate that the IR LED is clearly visible on the camera&#8217;s LCD display (strangely, it comes out looking blue, not red), so I looked at the IR diode through the camera—not lit up!  I double checked with the good part and it lit up very visibly.</p>
<p>I then checked the bad board for open circuits.  I quickly found that the resistor, which should be connected on one side to the ground plane was not connected to the ground pin of the header.  I re-examined all the solder joints, and one of the ones on the resistor looked a little bit less than perfect, so I reflowed the solder joints on the resistor.  Still nothing.</p>
<p>In desperation, I tried reflowing the solder joints on the header, although they all looked good.  Success!  It seems that the solder to the ground pad, though looking like a perfect connection, was not connecting. Now the second photogate is working just as well as the first, and I&#8217;m feeling very sheepish about having trusted visual inspection of a solder joint—I should know better than to do that.  I certainly should have done a better job of debugging before complaining to SparkFun, who were very nice about replacing the part, no questions asked.</p>
<p>So what can I do?  I feel I owe Sparkfun for the $1.95 part they sent me, but I&#8217;m not sure that the effort to get them the money wouldn&#8217;t cost them so much in labor costs for handling something unusual that they would lose money on my attempt to pay them.  About all I can do is encourage others to do business with them, since they seem to have real superb customer service.</p>
<p>If anyone does get Sparkfun&#8217;s <a href="http://www.sparkfun.com/products/9299">photogate</a> and <a href="http://www.sparkfun.com/products/9322">breakout board</a>, look at the easy Lego mounting I have in <a title="More on pendulums" href="http://gasstationwithoutpumps.wordpress.com/2012/01/19/more-on-pendulums/">More on pendulums</a>, which was easy to set up and worked very well. And check your solder joints carefully!</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/photogate/'>photogate</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/soldering/'>soldering</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun/'>SparkFun</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/sparkfun-electronics/'>SparkFun Electronics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3397/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3397/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3397/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3397/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3397/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3397/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3397/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3397/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3397&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>What I&#8217;m teaching next year</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/20/what-im-teaching-next-year/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/20/what-im-teaching-next-year/#comments</comments>
		<pubDate>Sat, 21 Jan 2012 02:15:00 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[bioinformatics]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[higher education]]></category>
		<category><![CDATA[programming]]></category>
		<category><![CDATA[teaching]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3393</guid>
		<description><![CDATA[The Curriculum Leave Plan for our department was just approve by the Dean, so now I know what I&#8217;m teaching next year: Fall How to be a grad student.  That&#8217;s not its official name, but that&#8217;s what its purpose is.  I created this course and have taught it (except for Fall 2011) ever since.  I&#8217;ll [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3393&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>The Curriculum Leave Plan for our department was just approve by the Dean, so now I know what I&#8217;m teaching next year:</p>
<h4>Fall</h4>
<ul>
<li><em>How to be a grad student.</em>  That&#8217;s not its official name, but that&#8217;s what its purpose is.  I created this course and have taught it (except for Fall 2011) ever since.  I&#8217;ll find out if anything new was added this year, but otherwise this course is pretty straightforward for me to teach.</li>
<li><em>Bioinformatics: Models and Algorithms</em>.  I&#8217;ve been teaching this forever also.  I definitely plan to talk to the person who taught it this year, as we may be alternating years from here on, and I&#8217;d like to incorporate any novel stuff he did.</li>
</ul>
<h4>Winter</h4>
<p>no courses, but I&#8217;ll have to do some course design and prep work for Spring</p>
<h4>Spring</h4>
<ul>
<li><em>Introduction to Programming for Biologists and Biochemists.</em> I&#8217;ve never taught this course—for that matter I&#8217;ve never taught any large introduction-to-programming course, so I&#8217;m definitely going to have to do some prep work.  I need to find out what has been taught in this class in the past, what pedagogical tricks are needed to get math-phobic biologists to program, what texts (paper or on-line) are available and suitable, and so forth.  I suspect a big chunk of my winter quarter will be prepping for my first lower-division course in over a decade.</li>
<li><em>Senior Thesis Presentation. </em>I assume that this course is an attempt to get the senior thesis students to write their theses and prepare poster and oral presentations.  It strikes me that the last quarter of senior year is far too late for this.  They needed to start writing their senior theses when they started doing the projects updating drafts as they go, but I doubt that even one in ten will come in with an outline, much less a draft. Half of them probably will not be able to reconstruct what they have done from their inadequate notes in their lab notebooks, since their research advisers never made them write anything up in any detail and never looked at their lab notebooks or taught them what to record. (Not all the research advisers are so unhelpful with their undergrads, but enough are to make this course be too little, too late.)<br />
I&#8217;ve done something like this before, but a quarter earlier in the year, when students were still working on their thesis research.  The work load for providing student feedback is incredibly high (practically a full-time job for just this one course), and I expect it to be worse this coming year.</li>
</ul>
<p>There are no surprises for me in the official CLP—these are the courses that I had agreed to.  It is a higher than usual load, because the budget cuts meant we could not afford to hire instructors for some of the courses we usually use them for, and I volunteered to take on the intro programming course, so that we could continue to hire a lecturer for the popular Human Genome course.  It isn&#8217;t quite as high as the load I had last year, so I should survive it, but Spring will be rough.</p>
<p>&nbsp;</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/bioinformatics/'>bioinformatics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/higher-education/'>higher education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/programming/'>programming</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/teaching/'>teaching</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3393/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3393/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3393/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3393/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3393/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3393/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3393/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3393/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3393&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Pendulum lab went well</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/20/pendulum-lab-went-well/</link>
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		<pubDate>Sat, 21 Jan 2012 00:02:38 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[AP physics]]></category>
		<category><![CDATA[Arduino]]></category>
		<category><![CDATA[circular pendulum]]></category>
		<category><![CDATA[g]]></category>
		<category><![CDATA[gravity]]></category>
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		<category><![CDATA[Newton]]></category>
		<category><![CDATA[pendulum]]></category>
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		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3390</guid>
		<description><![CDATA[In today&#8217;s lab we derived the formula for the period of a simple pendulum (assuming the small-angle approximation), , then measured both circular and simple pendulums.  For the circular pendulum we measured the radius of the cone on the first orbit and the last orbit, the length of the string (the slant height of the [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3390&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In today&#8217;s lab we derived the formula for the period of a simple pendulum (assuming the small-angle approximation), <img src='http://s0.wp.com/latex.php?latex=T%3D+2%5Cpi+%5Csqrt%7BL%2Fg%7D&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='T= 2&#92;pi &#92;sqrt{L/g}' title='T= 2&#92;pi &#92;sqrt{L/g}' class='latex' />, then measured both circular and simple pendulums.  For the circular pendulum we measured the radius of the cone on the first orbit and the last orbit, the length of the string (the slant height of the cone), and approximated the period by timing 10 or 20 periods and dividing.  For the simple pendulum, we used the photogate setup described in <a title="More on pendulums" href="http://gasstationwithoutpumps.wordpress.com/2012/01/19/more-on-pendulums/">More on pendulums</a>, to get very precise and repeatable measurements of the period.  The hardest part for us was measuring the length of the pendulums, since the center of mass for the bob was not obvious and the exact position of the pivot was not obvious—these uncertainties probably resulted in length measurements being ±5mm, making a large contribution to inaccuracy.</p>
<p>Here is a table of the measurements (and calculated g) we made for the circular pendulum:</p>
<table>
<tbody>
<tr>
<th>Length cm</th>
<th>radius cm</th>
<th>num orbits</th>
<th>period sec</th>
<th>g cm/sec^2</th>
</tr>
<tr>
<td> 212.4</td>
<td> 48.6–46.6</td>
<td>10</td>
<td>2.90</td>
<td> 970.8–972.6</td>
</tr>
<tr>
<td> 212.4</td>
<td> 38–52.4</td>
<td>20</td>
<td>2.601</td>
<td> 959.8–974.7</td>
</tr>
<tr>
<td> 161.5</td>
<td> 58–60.5</td>
<td>20</td>
<td>2.501</td>
<td> 938.7–984.2</td>
</tr>
</tbody>
</table>
<p>The range of estimates for g is larger than I would like.  I think that the decay of the oscillation of the pendulum makes quite a difference.  The average of all the estimates of g is 967 gm/sec^2, which is rather low.</p>
<p>And for the simple pendulum:</p>
<table>
<tbody>
<tr>
<th>Length cm</th>
<th>num ticks</th>
<th>mean period sec</th>
<th>standard deviation</th>
<th>g cm/sec^2</th>
</tr>
<tr>
<td>207.2</td>
<td>47</td>
<td>2.8958</td>
<td>0.0050</td>
<td>975.4</td>
</tr>
<tr>
<td>171.3</td>
<td>74</td>
<td>2.6272</td>
<td>0.0065</td>
<td>979.8</td>
</tr>
<tr>
<td>95.5</td>
<td>89</td>
<td>1.9565</td>
<td>0.0025</td>
<td>984.9</td>
</tr>
<tr>
<td>54.7</td>
<td>58</td>
<td>1.4809</td>
<td>0.0042</td>
<td>984.7</td>
</tr>
<tr>
<td>28.7</td>
<td>44</td>
<td>1.0730</td>
<td>0.0019</td>
<td>984.0</td>
</tr>
</tbody>
</table>
<p>The pendulum ticked reliably for quite a while, and the periods were remarkably consistent.  The estimates of g from the simple pendulum are good to about 0.5%, which is the limitation of accuracy on our pendulum length measurements and close to the limit of the accuracy of the small-angle approximation.  The average of the 5 measurements looks good to about 0.2%, which seems pretty good to me, since we certainly weren&#8217;t measuring the lengths that accurately.</p>
<p>I looked up the gravitational field in Santa Cruz on <a href="http://www.wolframalpha.com/widgets/view.jsp?id=d34e8683df527e3555153d979bcda9cf">Wolfram Alpha&#8217;s gravitational fields widge</a>t:</p>
<div id="scannerresult_0200_1"><img title="total field | 9.7995 m/s^2  (meters per second squared)..." src="http://www4c.wolframalpha.com/Calculate/MSP/MSP5331a014i47g72ff1gg0000309ea0057cc9ggd5?MSPStoreType=image/gif&amp;s=48&amp;w=496&amp;h=269" alt="total field | 9.7995 m\/s^2  (meters per second squared)\nangular deviation from local vertical | 0.00322°  (degrees)\ndown component | 9.79945 m\/s^2  (meters per second squared)\nwest component | 3.4×10^-4 m\/s^2  (meters per second squared)\nsouth component | 0.0316 m\/s^2  (meters per second squared)\n(based on EGM2008 12th order model; 11 meters above sea level)" width="496" height="269" /></div>
<p>While the lab was running, one of the students wrote a <a class="zem_slink" title="Python (programming language)" href="http://www.python.org/" rel="homepage">Python</a> script (using <a href="http://numpy.scipy.org/">numpy</a> for mean and standard deviation) to read the data and compute the numbers in the table.  We could have talked directly to the <a class="zem_slink" title="Arduino" href="http://arduino.cc" rel="homepage">Arduino</a>, but it was simpler to cut the numbers from the Arduino serial monitor and paste them into a file for the script to read. That allowed us to keep the Arduino running throughout, and just cut and paste the good numbers, discarding the junk from starting or stopping the pendulum.</p>
<p>I&#8217;m quite pleased with the photogate setup, which was very simple to build and worked reliably during the experiment. Crudely wrapping tape around the string made a lumpy opaque object, whose rotation probably contributed to the standard deviation of the  period—having a smoother cylinder for the optical blocker would probably make the period measurement much more consistent.  But that would not improve the mean estimates much since errors in adjacent period measurements cancel.  I believe that our mean periods are much more accurate than the standard deviations suggests, with errors less than 1 per thousand.</p>
<p>I had to make one change in the Arduino code during the lab to accommodate all the different pendulum lengths—I had a dead time before recognizing the next pulse, to prevent getting 2 pulses per period as the string passed through the beam twice.  I started with a dead time of 1 second, which as a bit too long for the smallest pendulum.  Reducing the dead time to 500 msec for that pendulum made it count reliably.  Note that for the 2nd and 3rd pendulum, we measured for about 3 minutes without a bad time measurement, and could have gone longer if we had had the patience.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/ap-physics/'>AP physics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/arduino/'>Arduino</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/circular-pendulum/'>circular pendulum</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/g/'>g</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/gravity/'>gravity</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/high-school/'>high school</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/newton/'>Newton</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/pendulum/'>pendulum</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/photogate/'>photogate</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/physics/'>physics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3390/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3390/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3390/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3390/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3390/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3390/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3390/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3390/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3390&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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			<media:title type="html">total field &#124; 9.7995 m/s^2  (meters per second squared)...</media:title>
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		<title>More on pendulums</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/19/more-on-pendulums/</link>
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		<pubDate>Fri, 20 Jan 2012 05:42:26 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[AP physics]]></category>
		<category><![CDATA[Arduino]]></category>
		<category><![CDATA[circular pendulum]]></category>
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		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3382</guid>
		<description><![CDATA[In Newton&#8217;s measurement of g, I described a failed experiment to measure g with a motorized circular pendulum. Further experimentation on my own lead me to adopt for this week&#8217;s lab the standard approach using an unpowered circular pendulum.  The cone formed by the string can be described as having height , base radius , [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3382&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In <a title="Newton’s measurement of g" href="http://gasstationwithoutpumps.wordpress.com/2012/01/13/newtons-measurement-of-g/">Newton&#8217;s measurement of g</a>, I described a failed experiment to measure g with a motorized circular pendulum. Further experimentation on my own lead me to adopt for this week&#8217;s lab the standard approach using an unpowered circular pendulum.  The cone formed by the string can be described as having height <img src='http://s0.wp.com/latex.php?latex=h&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='h' title='h' class='latex' />, base radius <img src='http://s0.wp.com/latex.php?latex=R&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='R' title='R' class='latex' />, and hypotenuse <img src='http://s0.wp.com/latex.php?latex=L&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='L' title='L' class='latex' />, the length of the string.  If the circular pendulum has period <img src='http://s0.wp.com/latex.php?latex=T&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='T' title='T' class='latex' />, then <img src='http://s0.wp.com/latex.php?latex=g%3D+4%5Cpi%5E2+h%2FT%5E2&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g= 4&#92;pi^2 h/T^2' title='g= 4&#92;pi^2 h/T^2' class='latex' />(derived in the Newton post).  If we make the string long and push the pendulum with the right speed to get a nearly circular (rather than elliptical) motion, then <img src='http://s0.wp.com/latex.php?latex=h%3D%5Csqrt%7BL%5E2-R%5E2%7D&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='h=&#92;sqrt{L^2-R^2}' title='h=&#92;sqrt{L^2-R^2}' class='latex' /> is nearly constant for many orbits, and we can estimate the period with just a stopwatch by counting 20 or 30 periods.  Using a large enough mass means that neglecting air resistance is now reasonable (which it was not for the tiny mass I started with).</p>
<p>Thanks to John Burk for suggesting that I forget about the motor—that seems to be the best approach, even though I then can&#8217;t use the photogate to time the period.  I&#8217;m hopeful that we can measure the height and the period accurately enough to get within about 2% of the right value for <img src='http://s0.wp.com/latex.php?latex=g&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g' title='g' class='latex' />.</p>
<p>This week in addition to doing the circular pendulum right, I wanted to do simple pendulums.  I&#8217;ve assigned problem 4.P.89 in <a href="http://matterandinteractions.org/">Matter and Interactions</a>, which seems to be the only place in the book that simple pendulums are done.  It is a computational problem, since there isn&#8217;t an analytic solution (though the small-angle approximation works pretty well up to about 45°).  I hope the students have done that by tomorrow!</p>
<p>I wanted to measure the period of the pendulum directly (not averaging over many periods), to demonstrate that the amplitude does not matter much.  Unfortunately, I&#8217;ve not yet built a sensor that works for this. I tried using the photogate, but I could not hit the 1 cm gap consistently, even with a shorter pendulum.</p>
<p>I also tried using a magnetic sensor (using the circuit I used for the <a title="Speed of sound lab writeup" href="http://gasstationwithoutpumps.wordpress.com/2012/01/03/speed-of-sound-lab-writeup/">speed-of-sound lab</a>) with a magnet for the pendulum weight, but that triggered at random times as the magnet came close.  Even 20cm away the field was enough to trigger the detector, and I got almost random timings.  A magnetometer was no better than the coil and comparator, as the magnetic field varied chaotically (from movements of the magnet other than the simple pendulum swing, such as twirling on the string).  The magnetometer was usable as a compass, though, which is good, because I originally bought it for the robotics club to use as a compass.  There are some tricky points to using it as a compass, which I&#8217;ll talk about in a different post.</p>
<p>I then tried marking the top of the string with a bit of electrical tape and using the photogate there.  That was the most successful so far—if I hold the photogate steady enough, I can get readings repeatable to ±20msec, which is much better than I can do with any other approach I&#8217;ve tried.  For one pendulum hanging from the edge of my desk, I either got  two pulses at about 1.11 and 0.45 seconds or one pulse every 1.56 seconds, depending on whether the marker on the string passes all the way through the beam or blocks it continuously at the end of the swing. The random variation I get is probably because of holding the sensor by hand (to align with the string).</p>
<p>If I had a more rigid way to mount the sensor, I should be able get more consistent readings, so my main engineering task was to get a rigid pivot point on the ceiling beam (without making any holes) and mount the photogate in a rigid, but adjustable, way.  Of my two standard mechanical engineering techniques, duct tape and <a class="zem_slink" title="Lego" href="http://www.lego.com/" rel="homepage">Lego</a>, I chose Lego:</p>
<div id="attachment_3386" class="wp-caption alignleft" style="width: 410px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/photogate_on_lego.jpg"><img class="size-full wp-image-3386" title="photogate_on_lego" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/photogate_on_lego.jpg" alt="" width="400" height="600" /></a><p class="wp-caption-text">A view of the photogate mounted on the Lego beam next to the pendulum string.</p></div>
<div id="attachment_3384" class="wp-caption alignright" style="width: 410px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/photogate_closeup.jpg"><img class="size-full wp-image-3384" title="photogate_closeup" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/photogate_closeup.jpg" alt="" width="400" height="600" /></a><p class="wp-caption-text">Closeup of the photogate, showing the breakout board and sensor wedged between a plate and a beam, with a 2-plate spacer.</p></div>
<p>Having come up with a nice way to grip the photogate and still be able to swing a pendulum string into the gap, I connected the beam holding the photogate to the same right-angle platform that we had used last week for the motorized pendulum. This left a little gap that I could rest the <a class="zem_slink" title="Arduino" href="http://arduino.cc" rel="homepage">Arduino</a> board in, so that there was no tension on the wires to the photogate.</p>
<p>I was a bit worried that I might have to put my laptop on top of a ladder, since the USB cord is not very long, but I have a spare pair of USB-to-Cat5 converters (one set is for the robotics project), so I was able to make an extension cord out of a flexible Cat-5 Ethernet cable, giving me enough length to put my laptop safely on the desk.</p>
<div id="attachment_3385" class="wp-caption alignnone" style="width: 410px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/arduino-on-beam.jpg"><img class="size-full wp-image-3385" title="Arduino-on-beam" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/arduino-on-beam.jpg" alt="" width="400" height="600" /></a><p class="wp-caption-text">The same Lego that holds the photogate can also support the Arduino, so I don&#039;t need to hold anything in my hands.</p></div>
<p>I had two other ideas I haven&#8217;t tried: using one of the ultrasonic range finders to track the pendulum motion and using a video camera to time the motion.  These require interpolation of position data to estimate the period, so I&#8217;d rather avoid them for now. The top-of-string photogate will work (I think) for the simple pendulum, and the circular pendulum can be timed with a stopwatch averaged over many periods.  (I could even use the photogate timer as a stopwatch, though the resolution of the stop watch on my Casio wristwatch is 0.01 seconds, and human reflexes make anything less than 0.1 second pretty much noise.)</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/ap-physics/'>AP physics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/arduino/'>Arduino</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/circular-pendulum/'>circular pendulum</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/g/'>g</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/gravity/'>gravity</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/high-school/'>high school</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/lego/'>Lego</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/newton/'>Newton</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/pendulum/'>pendulum</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/photogate/'>photogate</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/physics/'>physics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3382/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3382/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3382/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3382/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3382/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3382/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3382/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3382/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3382&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>UCSC the only UC with Google virtual tour</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/19/ucsc-the-only-uc-with-google-virtual-tour/</link>
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		<pubDate>Fri, 20 Jan 2012 01:36:51 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[Google maps]]></category>
		<category><![CDATA[Street View]]></category>
		<category><![CDATA[UCSC]]></category>
		<category><![CDATA[virtual tour]]></category>

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		<description><![CDATA[According to Google&#8217;s Street View University Partners &#8211; Maps Help, the only University of California campus that currently has a virtual tour is UCSC. The &#8220;virtual tour&#8221; is not a tour so far as I can tell, but heavy Street View coverage of the campus.  The coverage of UCSC campus is adequate, including major roads [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3378&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>According to Google&#8217;s <a href="http://support.google.com/maps/bin/answer.py?hl=en&amp;answer=2418148">Street View University Partners &#8211; Maps Help</a>, the only University of California campus that currently has a virtual tour is UCSC.</p>
<p>The &#8220;virtual tour&#8221; is not a tour so far as I can tell, but heavy Street View coverage of the campus.  The coverage of UCSC campus is adequate, including major roads and the bike paths, but not including many of service roads and footpaths that a real tour would cover.  It would be good for Google to hire a student to walk a number of the paths (particularly some of the single-track trails in the woods, which are not properly mapped) with a geotagging street-view camera, to capture the campus more thoroughly.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/google-maps/'>Google maps</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/street-view/'>Street View</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/ucsc/'>UCSC</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/virtual-tour/'>virtual tour</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3378/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3378/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3378/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3378/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3378/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3378/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3378/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3378/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3378&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Bogus story in Science Times</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/19/bogus-story-in-science-times/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/19/bogus-story-in-science-times/#comments</comments>
		<pubDate>Thu, 19 Jan 2012 22:14:31 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[evolution]]></category>
		<category><![CDATA[experimental evolution]]></category>
		<category><![CDATA[flocs]]></category>
		<category><![CDATA[multicellular organism]]></category>
		<category><![CDATA[New York Times]]></category>
		<category><![CDATA[yeast]]></category>

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		<description><![CDATA[In this week&#8217;s Science Times (a section of Tuesday&#8217;s NY Times, and the only reason we buy a newspaper on Tuesdays), Carl Zimmer wrote and article Yeast Reveals How Fast a Cell Can Form a Body, which reports claims from William Ratcliff to have evolved a primitive form of multi-cellularity in yeast. I think that [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3375&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In this week&#8217;s Science Times (a section of Tuesday&#8217;s <a class="zem_slink" title="New York Times" href="http://www.newyorktimes.com" rel="homepage">NY Times</a>, and the only reason we buy a newspaper on Tuesdays), Carl Zimmer wrote and article <a href="http://www.nytimes.com/2012/01/17/science/yeast-reveals-how-fast-a-cell-can-form-a-body.html">Yeast Reveals How Fast a Cell Can Form a Body</a>, which reports claims from William Ratcliff to have evolved a primitive form of multi-cellularity in yeast.</p>
<p>I think that Mr. Zimmer may have been fooled.  The process described in the article, of yeast cells clumping together is known as <em>flocculation</em> and it a natural property of yeast that evolved (most likely) millions of years ago.  It has been well studied as it is critically important for beer brewers (even Wikipedia has an article  on <a href="http://en.wikipedia.org/wiki/Yeast_flocculation">yeast flocculation</a>). Standard lab strains often have a disabling mutation in one of the flocculation genes (for instance, strain S288C has a mutation in FLO8), since lab strains have been selected for non-flocculation. Some of these mutations are frame shifts and  it is generally very easy to restore flocculation to yeast by having a compensating mutation that restores the correct reading frame to the disabled gene.</p>
<p>Of course, Mr. Zimmer may have left out some crucial information from the paper. The article itself is</p>
<blockquote><p><span class="cit-auth cit-auth-type-author">William C. <span class="search-result-highlight">Ratcliff</span></span><span class="cit-sep cit-sep-separator">, </span><span class="cit-auth cit-auth-type-author">R. Ford Denison</span><span class="cit-sep cit-sep-separator">, </span><span class="cit-auth cit-auth-type-author">Mark Borrello</span><span class="cit-sep cit-sep-separator">,  </span><span class="cit-sep cit-sep-last-separator">and </span><span class="cit-auth cit-auth-type-author">Michael Travisano</span><span class="cit-title"><br />
Experimental evolution of multicellularity</span><br />
<cite><abbr class="site-title" title="Proceedings of the National Academy of Sciences"><a class="zem_slink" title="Proceedings of the National Academy of Sciences of the United States of America" href="http://www.pnas.org/" rel="homepage">PNAS</a></abbr> <span class="cit-print-date">2012 </span><span class="cit-sep cit-sep-after-article-pages">; </span><span class="cit-ahead-of-print-date"><span class="cit-sep cit-sep-before-article-ahead-of-print-date">published ahead of print </span>January 17, 2012<span class="cit-sep cit-sep-after-article-ahead-of-print-date">, </span> </span><span class="cit-doi"><span class="cit-sep cit-sep-before-article-doi">doi:</span><a class="libx-autolink" style="border-bottom:1px dotted;" title="DOI was not found" href="http://ucelinks.cdlib.org:8888/sfx_ucsc?url_ver=Z39.88-2004&amp;rft_val_fmt=info:ofi/fmt:kev:mtx:journal&amp;__char_set=utf8&amp;rft_id=info:doi/10.1073/pnas.1115323109&amp;rfr_id=info:sid/libxucsc&amp;rft.genre=article">10.1073/pnas.1115323109</a></span></cite></p></blockquote>
<p>and is open-access, so anyone can read it.</p>
<p>The authors claim that their &#8220;snowflake&#8221; phenotype differs from the flocs of flocculent strains of yeast:</p>
<blockquote><p><em>During this time each cell was seen to give rise to a new snowflake-type cluster, whereas aggregation was never seen, demonstrating that clusters arise via post-division adhesion and not by aggregation of previously separate cells</em> [as would be the case for flocs].</p></blockquote>
<p>They also distinguished their phenotype from another way yeast cells are known to cluster:</p>
<blockquote><p><em>The snowflake clusters are distinct from </em>S. cerevisiae<em> pseudohyphal phenotypes, which have filamentous elongate cells and arise under conditions of nutrient stress. Clustering in snowflake-phenotype yeast is independent of pseudohyphal growth, as the snowflake phenotype is stable under both high- and low-nutrient conditions. Individual cells within clusters retain the ancestral ability to form pseudohyphae when starved, but remain oval (not elongate) during standard culture conditions</em></p></blockquote>
<p>So they do seem to have observed a new phenotype for yeast, but it is it a new evolution (as they claim) or simply a new observation of something that evolved a long time ago? They do &#8220;evolution&#8221; but do not then look to see what has changed in the genome—probably because they know that they have just turned on a pre-existing gene and don&#8217;t want to spoil their fantasy of &#8220;evolving multicellularity&#8221;.</p>
<p>I&#8217;d need a lot more data to show that multicellularity had evolved within 60 days, as they claim.  It is so much more likely that they turned on a pre-existing pathway that is not normally on in the yeast strains people study.  If I had been refereeing this paper, I would have made them tone down their claims for having evolved something new—given that all replications resulted in the same phenotype, it was almost certainly a pre-existing possibility in the genome.  (I fault PNAS, which has such a crummy refereeing process that I refuse to referee for them.)</p>
<p>Disclaimer: I&#8217;m not a yeast biologist.  If the &#8220;snowflake&#8221; phenotype really is a new evolution, I&#8217;d like to hear about it from someone who is an expert on yeast, and what the evidence is that it is really newly evolved.</p>
<p>&nbsp;</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/evolution/'>evolution</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/experimental-evolution/'>experimental evolution</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/flocs/'>flocs</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/multicellular-organism/'>multicellular organism</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/new-york-times/'>New York Times</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/yeast/'>yeast</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3375/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3375/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3375/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3375/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3375/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3375/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3375/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3375/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3375&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Teaching is not quite like programming</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/18/teaching-is-not-quite-like-programming/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/18/teaching-is-not-quite-like-programming/#comments</comments>
		<pubDate>Thu, 19 Jan 2012 07:39:11 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[assessment]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[programming]]></category>
		<category><![CDATA[unit testing]]></category>

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		<description><![CDATA[In one of the comments at Kitchen Table Math, the sequel, SteveH compared teaching students to programming.  In particular, he was railing against holistic evaluations: If students can do a complex task, that really only means that they can do that one problem, no matter how much understanding is applied. If they can&#8217;t, it&#8217;s very [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3373&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In one of the comments at <a href="http://kitchentablemath.blogspot.com/2012/01/new-new-thing.html?showComment=1326945284608#c5949032316938612018">Kitchen Table Math, the sequel</a>, <a href="http://www.blogger.com/profile/03956560674752399562">SteveH</a> compared teaching students to programming.  In particular, he was railing against holistic evaluations:</p>
<blockquote><p><em>If students can do a complex task, that really only means that they can do that one problem, no matter how much understanding is applied. If they can&#8217;t, it&#8217;s very difficult to find the gap or problem in understanding. It reminds me of unit testing versus system testing in programing. Testing doesn&#8217;t start at the &#8220;authentic&#8221; system level. You might define tests that work, but you will never properly exercise the code.</em></p>
<p><em>For any complex system, you have to validate the parts before you put them together to test and validate the whole. For education, you have to validate that students have mastered basic skills before letting them loose on complex &#8220;authentic&#8221; or real world problems.</em></p></blockquote>
<p>This analogy seemed pretty reasonable at first, so I thought about how in interacts with my own assessment methods.  I&#8217;m usually dealing with students at a fairly advanced level, and there is no way that I could assess them on all the basic skills they are supposed to have acquired over the preceding 16 years of their education.  The new skills I want them to develop are layered on top of the writing, math, biology, and programming skills and knowledge they are supposed to already have.  I can test some of the new skills incrementally (and I do to some extent, having usually 6 programs of gradually increasing difficulty, plus a couple of papers), but most of the problems I uncover tend to be underlying problems in their previous training.</p>
<p>I disagree with him that evaluating a complex task results in only one bit of information (they can or can&#8217;t do it).  The complex task produces a complex output that can be debugged—though not always easily. So my teaching and assessment is often more like debugging someone else&#8217;s poorly tested and undocumented library.  I can&#8217;t write unit tests for everything in the library—I can&#8217;t even figure out what is in the library, but I can look for errors in the output and try to trace them back to their sources. That is why it takes me forever to grade programs or papers—I&#8217;m not doing a pass/no-pass assessment, but attempting to debug the underlying thought processes of the person. Like all debugging tasks, it is difficult and the first guess at the problem is usually wrong.</p>
<p>I would love it if the students I taught had all been excellently educated and I knew precisely what their skills were (like tested and documented libraries).  But that is a fantasy world.  Every one of my students comes in with a different skill set, often with great strengths in some areas and unexpected holes in others. Part of my job is to try to identify some of those holes and point them out to the students, so that they can patch them up. Another part is to help them build new capabilities on top of what they already have.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/assessment/'>assessment</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/programming/'>programming</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/unit-testing/'>unit testing</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3373/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3373/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3373/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3373/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3373/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3373/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3373/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3373/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3373&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Where does learning happen?</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/16/where-does-learning-happen/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/16/where-does-learning-happen/#comments</comments>
		<pubDate>Mon, 16 Jan 2012 15:21:12 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[flipped classroom]]></category>

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		<description><![CDATA[The Chronicle of Higher Education has a rather lightweight article about a Stanford student complaining about the online machine-learning class at Stanford: Debating the &#8216;Flipped Classroom&#8217; at Stanford.  There was, however, some very interesting discussion in the comments. One commenter, Derek Bruff, summarized the pro-flipped-classroom position well: As Eric Mazur often points out, in the [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3369&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>The Chronicle of Higher Education has a rather lightweight article about a Stanford student complaining about the online machine-learning class at Stanford: <a href="http://chronicle.com/blogs/wiredcampus/debating-the-flipped-classroom-at-stanford/34811">Debating the &#8216;Flipped Classroom&#8217; at Stanford</a>.  There was, however, some very interesting discussion in the comments.</p>
<p>One commenter, Derek Bruff, summarized the pro-flipped-classroom position well:</p>
<blockquote><p><em>As Eric Mazur often points out, in the traditional model, the &#8220;transfer&#8221; of information happens during class and the &#8220;assimilation&#8221; of that information—the much harder step—happens after class when students are on their own. Why not move the harder step to class time, during which the instructor and other students are around to help?</em></p>
<p><em>In the inverted classroom, it&#8217;s still important that students spend time outside of class doing work (and that can be problematic for the reasons you point out in your blog post), but the hardest work happens during class when the teacher is around to help. </em></p>
<p>[Derek is responding to a comment by Ira Socol which pointed to several blog posts. I think the one he means is <a href="http://speedchange.blogspot.com/2012/01/changing-gears-2012-rejecting-flip.html">Changing Gears 2012: rejecting the "flip" </a>.]</p></blockquote>
<p>I&#8217;ve been thinking about that pedagogical assumption: that assimilation of information works best if it happens during class when the teacher is around to help.  I can&#8217;t decide if I really believe it.</p>
<p>Certainly my deepest understanding of material has come when I&#8217;ve worked with it extensively on my own—writing programs, doing mathematical derivations, writing papers, … .  Having other people around when I&#8217;m doing this just makes it harder to focus, and does not aid in the assimilation.</p>
<p>But initial entry into the material is aided by having a guide who can quickly point me to productive lines of thought, so that I don&#8217;t flail around on trivia.  Some forms of learning are definitely helped by having interaction with the teacher as the practice is done (physical training like martial arts, dance, and sports seem to particularly benefit from supervised practice).</p>
<p>My son is taking an online calculus class that meets in a chat room once a week.  That time is spent doing a lecture with students asking questions for clarification, and he often refers back to the lecture transcript (an advantage of the chat-room format is that you get a full transcript, which is much easier to search than a video) rather than to the book for clarification of methods. Even my son, who is a diligent, top student, rarely reads the calculus book before class (or afterwards for that matter—he seems to get most of his information from the chat-room lecture, though I think that the book they are using is one of the best I&#8217;ve seen for top students).</p>
<p>But most of the learning takes place when he does the problem sets, not in the class.  There is an opportunity for the students to interact on the homework: there is a forum where the students can publish their solutions, ask one another for help, or read other students&#8217; solutions (there is a social convention of hiding the solutions so that it requires an extra click to get them, so that no one looking at the forum is forced to see solutions before they want to).  My son posts solutions to all the problems, and I believe that there is some social status associated with doing so, though no explicit recognition from the instructors.  Still, the learning is not happening on the forum—it is happening when the problems are solved, with the forums providing an incentive for doing the individual work. The forums do also provide for communication with the instructor—particularly for clarification of confusing points in the homework problems or lectures.</p>
<p>Just this last week, we experimented with another approach: he and I each took a small (2&#8242; × 3&#8242;) whiteboard and simultaneously worked independently on the same problem.  I sometimes had to ask him about what they had covered in class, as I&#8217;ve not done integration for 30 years  and have forgotten some of the techniques. I admit that I struggled a bit with <img src='http://s0.wp.com/latex.php?latex=%5Cint+x+e%5Ex+cos%28x%29+dx&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='&#92;int x e^x cos(x) dx' title='&#92;int x e^x cos(x) dx' class='latex' />, though I eventually came up with a simpler solution than my son did, by &#8220;cheating&#8221; and using <img src='http://s0.wp.com/latex.php?latex=cos%28x%29+%3D+%5Cmbox%7BRe%7D+e%5E%7Bix%7D&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='cos(x) = &#92;mbox{Re} e^{ix}' title='cos(x) = &#92;mbox{Re} e^{ix}' class='latex' />.  Integration by parts was always the least fun part of calculus for me. When we both finished a problem, we compared solutions, and then each looked for algebra errors if we got different results.  This provided more social interaction than working alone on a problem and the slightly competitive nature of trying to finish quicker with a more accurate answer resulted in the homework problems being done faster.</p>
<p>I think that this sort of synchronized but mostly independent work can be a good way to combine the individual effort needed for learning with some social incentives for doing it, as long as the problems are small enough ones and the people working on them are working at about the same pace.  (I&#8217;m rusty enough on my calculus that I&#8217;m at about the same pace as my son who is just learning it.)  I can&#8217;t see it working in a classroom, where students are likely to have a 5-fold different range of the pace at which they work—the faster students will be bored to tears and the slower students will be left behind.  I also don&#8217;t see it working in classes involving bigger problems (like programming projects that take &gt;10 hours to do).</p>
<p>My son has developed a very different way of working on his science-fair project, which involves talking with me or his postdoc mentor at the university about the problem he is working on, then going and spending hours coding and testing.  He learns little bits from books, from Wikipedia, and from conversations (like what a decision tree is, or feature selection, or how to calculate entropy), but it is the hours of coding and testing by himself that really makes the ideas his.  He needs the contact with others to talk through points where he gets stuck, though often all he needs is a sympathetic ear and not guidance by an instructor.  The need for interaction is hard to schedule, though, as it does not come a fixed intervals—sometimes he needs to be left alone for days to write his programs, other times he wants to check on ideas every half hour.  This is one advantage of home schooling or (for the fantastically rich) a live-in tutor: learning on demand, without the tyranny of a class schedule.</p>
<p>I&#8217;ve often wondered whether the desirability of the flipped classroom is in extravert/introvert thing: as an introvert, I find working in a group that is trying to interact as they work extremely draining.  So much effort for so little accomplished! The traditional lecture classroom is much more suited for introverts, as there are only occasional social interactions required, and they are more like performances than like ordinary social interactions, and so are less stressful. (I know, extraverts can&#8217;t imagine performance being less stressful than ordinary social interaction, but introverted actors and professors may understand.) I think I might not have made it through college and grad school if my classes had all been &#8220;flipped classrooms&#8221; that relied on having &#8220;instructors and students around to help&#8221;.</p>
<p>I thought about using some of my sabbatical to record mini-lectures on various topics to experiment with a &#8220;flipped classroom&#8221; next year, but I doubt now that I&#8217;ll do it.  My lectures are extemporaneous performances that would be very hard to do without the interaction with a live audience, and I&#8217;m not convinced that flipping would really help learning any—the students are still going to have to spend many hours outside class struggling with their programs, and having to watch videos as well just reduces the time they have for the programming.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/flipped-classroom/'>flipped classroom</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3369/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3369/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3369/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3369/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3369/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3369/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3369/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3369/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3369&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Individual work in collaborations</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/15/individual-work-in-collaborations/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/15/individual-work-in-collaborations/#comments</comments>
		<pubDate>Sun, 15 Jan 2012 20:09:47 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[bioinformatics]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[group work]]></category>
		<category><![CDATA[Helicobacter pylori]]></category>
		<category><![CDATA[research]]></category>

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		<description><![CDATA[I have protested in this blog before about the excessive use of inappropriate group work in schools, though recognizing that there are projects that are big enough or varied enough that groups are the appropriate way to tackle them. A much more eloquent article on the subject by Susan Cain was just published in the [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3366&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>I have <a title="Group work" href="http://gasstationwithoutpumps.wordpress.com/2010/07/17/group-work/">protested in this blog before about the excessive use of inappropriate group work in schools</a>, though recognizing that there are projects that are big enough or varied enough that groups are the appropriate way to tackle them.</p>
<p>A much more eloquent article on the subject by Susan Cain was just published in the <a class="zem_slink" title="New York Times" href="http://www.newyorktimes.com" rel="homepage">NY Times</a>: <a href="http://www.nytimes.com/2012/01/15/opinion/sunday/the-rise-of-the-new-groupthink.html?_r=1&amp;pagewanted=all">The Rise of the New Groupthink</a>.</p>
<p>There are nice sound bites like</p>
<blockquote><p><em>But decades of research show that individuals almost always perform better than groups in both quality and quantity, and group performance gets worse as group size increases.</em></p></blockquote>
<p>She does suggest that on-line brainstorming may work better than in-person brainstorming, quoting Proust&#8217;s description of reading as a &#8220;miracle of communication in the midst of solitude&#8221;.  Her prescription for effective teamwork seems reasonable to me:</p>
<blockquote><p><em>To harness the energy that fuels both these drives, we need to move beyond the New Groupthink and embrace a more nuanced approach to creativity and learning. Our offices should encourage casual, cafe-style interactions, but allow people to disappear into personalized, private spaces when they want to be alone. Our schools should teach children to work with others, but also to work on their own for sustained periods of time. And we must recognize that introverts like Steve Wozniak need extra quiet and privacy to do their best work. </em></p></blockquote>
<p>I certainly have found that my best collaborative work has come out of fairly incidental contacts (meeting someone from another department in a hallway, chatting after a research seminar, talking with a student in someone else&#8217;s research group), followed by days or weeks of intensive work on the problem.</p>
<p>My sabbatical this year has been going through fertile and dead periods.  The dead periods have been times when I was not getting any contact with students and colleagues, and was not getting anything done.  The fertile periods were intense bursts of activity by myself after a chance contact with someone sparked an interest in a particular problem.</p>
<p>Most recently, I&#8217;ve been working on putting together a bioinformatics protocol that will let us reconstruct the cagY genes from hundreds of strains of <em>Helicobacter pylori</em> using PacBio sequencing.  Most of the sequencing technologies are not suitable for this gene, as it has long blocks of many repeats that vary from strain to strain.  Because the tandem replication is very recent (divergence between the strains may be only a few generations earlier) and there is selective pressure to maintain the open reading frame, the different repeats are often identical for long stretches, making short-read data nearly impossible to assemble. Even Sanger sequencing to confirm the gene assembly is difficult, as it is hard to find unique primer locations.</p>
<p>I started this project as a result of a short discussion with a couple of <em>H. pylori</em> researchers, but I spent weeks writing programs and Makefiles, testing them, twiddling parameters to see if they were robust, and so on.  I could not have done the work without the collaboration (I needed someone who had a difficult, interesting problem and the data to work on), but I could not have done the work if someone had kept interrupting me or making suggestions either.  The project would probably have died halfway through if I had had to do it with my usual teaching load, as I was spending 12–16 hours a day on it for weeks.</p>
<p>I need to alternate between working alone and contact with others. Sometimes talking through a problem with someone who understands and can ask good questions helps me clarify my thinking, after which I need hours or days to work out the details, after which I want to share again.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/bioinformatics/'>bioinformatics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/group-work/'>group work</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/helicobacter-pylori/'>Helicobacter pylori</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/research/'>research</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3366/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3366/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3366/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3366/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3366/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3366/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3366/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3366/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3366&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>How many AP courses are too many?</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/14/how-many-ap-courses-are-too-many/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/14/how-many-ap-courses-are-too-many/#comments</comments>
		<pubDate>Sun, 15 Jan 2012 06:17:12 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[Advanced Placement]]></category>
		<category><![CDATA[AP]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[high school]]></category>

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		<description><![CDATA[Jill Tucker, a San Francisco Chronicle staff writer wrote an article this week on AP courses: Stressful AP courses &#8211; a push for a cap. At some of the Bay Area&#8217;s most competitive public and private high schools, teachers and counselors have started pushing for a cap on the number of Advanced Placement courses a [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3363&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>Jill Tucker, a <a class="zem_slink" title="San Francisco Chronicle" href="http://sfgate.com/" rel="homepage">San Francisco Chronicle</a> staff writer wrote an article this week on AP courses: <a href="http://www.sfgate.com/cgi-bin/article.cgi?f=%2Fc%2Fa%2F2012%2F01%2F08%2FMN9A1MLR0Q.DTL">Stressful AP courses &#8211; a push for a cap</a>.</p>
<blockquote><p><em>At some of the Bay Area&#8217;s most competitive public and private high schools, teachers and counselors have started pushing for a cap on the number of Advanced Placement courses a student can take.</em></p></blockquote>
<p>The problem she outlined is clear: many students are taking so many AP classes that they have no time for anything else.</p>
<p>Why? A lot of colleges (including University of California) give a bonus point on grades for honors and AP courses, and with grade inflation causing most grades now to be As, there is no way to distinguish good students from mediocre ones except by how challenging their courses are.  She mentions that last year the average GPA of accepted freshmen at UCLA was 4.34, but <a href="http://www.universityofcalifornia.edu/admissions/campuses/ucla/freshman-profile/index.html">the official UCLA freshman profile for 2011</a> says 4.11 (UCB is higher at 4.14, and no UC is close to 4.34).</p>
<p>For a student to get a 4.14 GPA with a typical high-school load of 24–28 classes, they must get straight As and take at least 4 honors courses (or get an occasional lower grade but take even more honors classes to compensate).</p>
<p>AP classes are intended to be college-equivalent classes taken in high school. When the program was started it was used for small numbers of students who needed more challenge than the high schools normally provided (about 40 students in my high school class of around 600 were taking AP-level courses, and that was an unusually academic school).  Now, with everyone who wants to get into a name-brand college taking AP courses, they have gotten watered down to the point where they are roughly the equivalent of the standard &#8220;college track&#8221; courses of 40 years ago, and more and more colleges are refusing to give credit for passing the AP exam.</p>
<p>The workload in the courses is often large, because teachers remember how many hours of homework they had in college and think that they should assign the same amount in high school, forgetting that college students have fewer classes at once and spend many fewer hours in class.  So the workload (class+homework) of AP classes is often much larger than for the corresponding college classes, but the quality is highly variable (some are much better than corresponding college classes, some are much worse).</p>
<p>What is a student or parent to do?  Taking no AP or honors courses generally makes the student look like they are not interested in academics, so even those colleges that don&#8217;t give bonus points for AP courses are likely to downgrade the student somewhat.  Taking huge numbers of AP courses gives no room for students to pursue their passions, and often indicates an education heavy on memorization and cramming for tests, rather than deep understanding.</p>
<p>Probably the most reasonable course is for students to take AP courses (and exams!) in those subjects that most interest them and pursue interests outside the AP classroom.  Community college courses that go beyond the AP courses are also a cost-effective choice, if you can get in.</p>
<p>For students interested in STEM majors, I recommend taking AP calculus (at least AB, and BC if it is offered), AP Physics B (or C, though that is rare for high schools to offer), AP statistics, and AP chemistry.  Those interested in bio or health careers could take AP Bio, but at the moment it is too much work for too little reward—a non-AP bio course may cover less material but get students to end up understanding more.  (That may get fixed in the next couple of years as teacher adapt to the new AP Bio curriculum and reduce the &#8220;memorize a million factoids&#8221; approach.)  In addition to the core AP courses, only one or two others should be taken, based on student strengths (a foreign language, English, art, or history, for example).  More important for a STEM student is to do research projects and enter them in county (and state and international, if possible) science fairs, or to join robotics clubs and do engineering projects.</p>
<p>I don&#8217;t know what advice to give humanities students—I guess the corresponding advice would be to enter essay contests, write for local literary magazines, do book reviews for the student paper, send history articles to <a href="http://www.tcr.org/">Concord Review</a>, and so forth.  Intensive immersion programs in foreign languages might also look good.</p>
<p>Showing independent interest in a subject by doing it outside of courses is more impressive than getting an extra point for the GPA by taking an AP class.</p>
<p>Schools, however, should not ration the AP courses, as they have not shown great ability in the past in being able to determine who can and who can&#8217;t benefit from the courses.  It is far better to let students and parents choose, as long as students meet the prerequisites for the courses (so the courses don&#8217;t get further watered down).  The schools should not be pushing everyone into AP courses (as some schools seem to be doing), but neither should they be holding back kids who want to take them.</p>
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		<title>Typing speed</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/14/typing-speed/</link>
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		<pubDate>Sun, 15 Jan 2012 04:48:28 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[typing speed]]></category>
		<category><![CDATA[typing test]]></category>

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		<description><![CDATA[I usually warn female engineering students not to put typing speed on their resumes, to avoid getting stereotyped as typists rather than engineers. But being able to type quickly and accurately is an important skill for an engineer (or anyone else who works on a computer). I gave myself a typing test using one of [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3360&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>I usually warn female engineering students not to put typing speed on their resumes, to avoid getting stereotyped as typists rather than engineers. But being able to type quickly and accurately is an important skill for an engineer (or anyone else who works on a computer). I gave myself a typing test using one of the many on-line tools for the job:</p>
<p><a href="http://speedtest.10fastfingers.com"><img src="http://speedtest.10fastfingers.com/badge/1_wpm_score_BA.png" alt="Typing Test Score" /></a></p>
<p>I&#8217;d be a lot faster if I did not make so many mistakes and have to keep back-spacing. I actually had a typing class in high-school, back in the days when you had to hit the keys pretty hard and slipping off a key could mean getting your finger caught between the keys. My first typewriter was an extremely heavy manual &#8220;portable&#8221; with an 11&#8243; carriage (so you could put paper in sideways). Its keys were so stiff that I could not operate them with my little fingers, so I quickly lost the typing technique taught in class and created my own style which used only three fingers on each hand, plus the right thumb for spaces. I was trying to observe what I do now, and it seems that I use all the fingers of the left hand, and only two on the right, plus the right thumb. Of course when I&#8217;m trying to be aware of my fingers, the usage of them changes, but I think I use the little finger of the left hand only for shifting.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/typing-speed/'>typing speed</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/typing-test/'>typing test</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3360/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3360/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3360/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3360/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3360/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3360/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3360/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3360/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3360&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Newton&#8217;s measurement of g</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/13/newtons-measurement-of-g/</link>
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		<pubDate>Sat, 14 Jan 2012 06:02:37 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[AP physics]]></category>
		<category><![CDATA[circular pendulum]]></category>
		<category><![CDATA[g]]></category>
		<category><![CDATA[gravity]]></category>
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		<category><![CDATA[Newton]]></category>
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		<description><![CDATA[In Chapter 5 of Matter and Interactions, the authors describe an experiment that Newton did to measure , the gravitational field at the surface of the Earth.  The idea is a simple one: have a pendulum moving in a circle.  The size of the circle is a function of the length of the pendulum, the [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3339&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<div id="attachment_3340" class="wp-caption alignleft" style="width: 410px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/pendulum_on_beam.jpg"><img class="size-full wp-image-3340" title="Pendulum_on_beam" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/pendulum_on_beam.jpg" alt="" width="400" height="600" /></a><p class="wp-caption-text">The motor for the circular pendulum mounted on a ceiling beam, with a short string attached.</p></div>
<p>In Chapter 5 of <a href="http://matterandinteractions.org/">Matter and Interactions</a>, the authors describe an experiment that Newton did to measure <img src='http://s0.wp.com/latex.php?latex=g&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g' title='g' class='latex' />, the gravitational field at the surface of the Earth.  The idea is a simple one: have a pendulum moving in a circle.  The size of the circle is a function of the length of the pendulum, the speed of rotation, and <img src='http://s0.wp.com/latex.php?latex=g&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g' title='g' class='latex' />. So I thought it would be fun to do an experiment along those lines in physics lab today.</p>
<p>The first step was to make a circular pendulum that could be driven to move at a constant speed.  My idea here was to build something out of <a class="zem_slink" title="Lego" href="http://www.lego.com/" rel="homepage">Lego</a>, so that we could adjust the speed as needed with pulleys and belts. My son and I built such a device early in the week and put it up on one of the ceiling beams in the room where we do our physics labs.  I put it up that high so that we could have a long string for the pendulum that would be easy to measure.  I had not done any calculations, just guessed that the bead on the string would fly out as we spun the shaft.</p>
<p>We had quite a surprise when we tried it out with a fast-spinning motor (about  9Hz or 540rpm) and a 2m long string.  The bead hung straight below the motor, but the string bowed out in several places, forming a nice pattern of nodes and antinodes. Changing the speed of the motor changed the number of nodes and antinodes. That is where I stopped the pre-lab preparation—the rest of the lab was done with the students.</p>
<p>The first thing we did was rederive the formulas the motion of the mass at the end of the pendulum, using the new whiteboards I had made for the class.  The whiteboards cost under $8 each for 2 2&#8242;×3&#8242; boards—the lumberyard sells dry-erase hardboard for $1 a square foot (less if you buy a full sheet, but that was too hard to get home on my bike), plus $1 for the cutting.  The rest was the cost of the duct tape for the edge and taxes.</p>
<p>The cone formed by the string can be described as having height <img src='http://s0.wp.com/latex.php?latex=h&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='h' title='h' class='latex' />, base radius <img src='http://s0.wp.com/latex.php?latex=R&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='R' title='R' class='latex' />, and hypotenuse <img src='http://s0.wp.com/latex.php?latex=L&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='L' title='L' class='latex' />, the length of the string.  The idea was to measure <img src='http://s0.wp.com/latex.php?latex=L&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='L' title='L' class='latex' />, <img src='http://s0.wp.com/latex.php?latex=R&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='R' title='R' class='latex' />, and the period of the pendulum <img src='http://s0.wp.com/latex.php?latex=T&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='T' title='T' class='latex' />, and from these try to calculate <img src='http://s0.wp.com/latex.php?latex=g&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g' title='g' class='latex' />.</p>
<div id="attachment_3342" class="wp-caption alignleft" style="width: 610px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/whiteboard.jpg"><img class="size-full wp-image-3342" title="whiteboard" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/whiteboard.jpg" alt="" width="600" height="400" /></a><p class="wp-caption-text">One of the new whiteboards.</p></div>
<p>We neglected air resistance (probably not a good idea) and so had just two forces acting on the mass: the gravitational attraction to the Earth <img src='http://s0.wp.com/latex.php?latex=%280%2C+-mg%2C+0%29&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='(0, -mg, 0)' title='(0, -mg, 0)' class='latex' /> and the diagonal pull from the string with magnitude <img src='http://s0.wp.com/latex.php?latex=F_s&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='F_s' title='F_s' class='latex' />. We can get the horizontal and vertical components of the force exerted by the string: <img src='http://s0.wp.com/latex.php?latex=F_s%28R%2FL%2C+h%2FL%29&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='F_s(R/L, h/L)' title='F_s(R/L, h/L)' class='latex' />. The vertical component must match the force due to the Earth as the mass is not moving vertically, so <img src='http://s0.wp.com/latex.php?latex=F_s+h%2FL%3Dmg&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='F_s h/L=mg' title='F_s h/L=mg' class='latex' />, or <img src='http://s0.wp.com/latex.php?latex=F_s+%3D+mgL%2Fh&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='F_s = mgL/h' title='F_s = mgL/h' class='latex' />. The magnitude of horizontal component is <img src='http://s0.wp.com/latex.php?latex=F_s+R%2FL%3D+mg+R%2Fh&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='F_s R/L= mg R/h' title='F_s R/L= mg R/h' class='latex' />.</p>
<p>The horizontal component is what is accelerating the mass around the circle.  We rederived the formula for that by describing the position of the mass in the complex plane <img src='http://s0.wp.com/latex.php?latex=%5CXi%28t%29+%3D+R+e%5E%7Bi%5Comega+t%7D&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='&#92;Xi(t) = R e^{i&#92;omega t}' title='&#92;Xi(t) = R e^{i&#92;omega t}' class='latex' /> and taking the derivative twice: <img src='http://s0.wp.com/latex.php?latex=d%5E2+%5CXi%28t%29+%2F+dt%5E2+%3D+-R+%5Comega%5E2+e%5E%7Bi%5Comega+t%7D&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='d^2 &#92;Xi(t) / dt^2 = -R &#92;omega^2 e^{i&#92;omega t}' title='d^2 &#92;Xi(t) / dt^2 = -R &#92;omega^2 e^{i&#92;omega t}' class='latex' />.  One of the students was very comfortable with this, the other (who had ostensibly had more calculus), had never seen <img src='http://s0.wp.com/latex.php?latex=e%5E%7Bi+%5Comega%7D&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='e^{i &#92;omega}' title='e^{i &#92;omega}' class='latex' />.  I gave a very brief mention of doing it with sines and cosines, but did not take the time to do the derivation in those terms.  Note that the magnitude of the force is <img src='http://s0.wp.com/latex.php?latex=m+R%5Comega%5E2&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='m R&#92;omega^2' title='m R&#92;omega^2' class='latex' /> and it is directed towards the center of the circle, as we would expect.  The angular frequency <img src='http://s0.wp.com/latex.php?latex=%5Comega&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='&#92;omega' title='&#92;omega' class='latex' /> is just the speed in radians per second, so <img src='http://s0.wp.com/latex.php?latex=%5Comega%3D2%5Cpi%2FT&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='&#92;omega=2&#92;pi/T' title='&#92;omega=2&#92;pi/T' class='latex' />.</p>
<p>Combining the two formulas for the horizontal force, we get <img src='http://s0.wp.com/latex.php?latex=mgR%2Fh+%3D+mR%5Comega%5E2+%3D+m+R+4+%5Cpi%5E2+%2FT%5E2&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='mgR/h = mR&#92;omega^2 = m R 4 &#92;pi^2 /T^2' title='mgR/h = mR&#92;omega^2 = m R 4 &#92;pi^2 /T^2' class='latex' />.  We can simplify this to <img src='http://s0.wp.com/latex.php?latex=g%3D4+%5Cpi%5E2+h%2FT%5E2&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g=4 &#92;pi^2 h/T^2' title='g=4 &#92;pi^2 h/T^2' class='latex' />.  If we don&#8217;t want to measure <img src='http://s0.wp.com/latex.php?latex=h&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='h' title='h' class='latex' />,we can use Pythagoras&#8217;s Theorem to get <img src='http://s0.wp.com/latex.php?latex=g%3D+4%5Cpi%5E2+%5Csqrt%7BL%5E2-R%5E2%7D%2FT%5E2&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g= 4&#92;pi^2 &#92;sqrt{L^2-R^2}/T^2' title='g= 4&#92;pi^2 &#92;sqrt{L^2-R^2}/T^2' class='latex' />. After demonstrating the unexpected behavior of the long string, I challenged the students to compute <img src='http://s0.wp.com/latex.php?latex=h&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='h' title='h' class='latex' /> from the known value of <img src='http://s0.wp.com/latex.php?latex=g&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g' title='g' class='latex' />.</p>
<p>To do the calculation we needed the period <img src='http://s0.wp.com/latex.php?latex=T&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='T' title='T' class='latex' />. In preparation for this, I had bought a &#8220;<a href="http://www.sparkfun.com/products/9299">photo interrupter</a>&#8221; from <a class="zem_slink" title="SparkFun Electronics" href="http://www.sparkfun.com/commerce/categories.php" rel="homepage">Sparkfun</a> and a breakout board to mount it. (Actually, I ordered 2, which was a good thing, since one of them did not work—Sparkfun is sending me a replacement).</p>
<div id="attachment_3344" class="wp-caption alignnone" style="width: 610px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/closeup_photo_gate.jpg"><img class="size-full wp-image-3344 " title="closeup_photo_gate" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/closeup_photo_gate.jpg" alt="" width="600" height="400" /></a><p class="wp-caption-text">Photo interrupter with a 1cm gap between the infrared LED and the detector.</p></div>
<p>I hooked up the photo interrupter to my <a class="zem_slink" title="Arduino" href="http://www.arduino.cc/en/" rel="homepage">Arduino</a> microprocessor, which I programmed to measure the time between falling edges of pulses (with a 20msec minimum pulse width). By letting the Lego beam on the motor pass through the gap, I could get pretty consistent measurements of the period. Because the beam is not quite centered, I believe I was getting just one end to pass through the gap. I could have made the measurement easier by having a piece of opaque tape sticking out the end of the beam to pass through the gap. I believe that the period as the motor was initially set up was 119 msec. The students computed that this should result in lifting the mass by 3.5 mm, which is a bit small to measure at the end of a 2m string!</p>
<div id="attachment_3345" class="wp-caption alignnone" style="width: 610px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/photo_gate_and_arduino.jpg"><img class="size-full wp-image-3345" title="photo_gate_and_Arduino" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/photo_gate_and_arduino.jpg" alt="" width="600" height="500" /></a><p class="wp-caption-text">Photo interrupter hooked up to an Arduino microprocessor, connected in turn to a laptop.</p></div>
<div id="attachment_3346" class="wp-caption alignright" style="width: 260px"><a href="http://gasstationwithoutpumps.files.wordpress.com/2012/01/pendulum_on_desk.jpg"><img class="size-full wp-image-3346 " title="Pendulum_on_desk" src="http://gasstationwithoutpumps.files.wordpress.com/2012/01/pendulum_on_desk.jpg" alt="" width="250" height="600" /></a><p class="wp-caption-text">Pendulum on desk with short string.</p></div>
<p>The next step was to have the students compute a period that would involve a decent value for <img src='http://s0.wp.com/latex.php?latex=h&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='h' title='h' class='latex' />, say 20 cm. They computed it to be about 0.9 seconds, which was easily arranged by changing the pulleys on the motor and shaft. We then shortened the string to about 30 cm, and put the motor on the desk. I forget exactly what the period turned out to be: something close to 910 msec, I believe. We did not take careful notes, because we were still playing around with the setup when it was time to end the class (one student&#8217;s mother came to fetch him, another had to go off to improv class, and I had a meeting with 4 grad students and an AP bio teacher about a bioinformatics lesson the students are going to do for his classes in 2 weeks).</p>
<p>Why were we still fussing around? Well, when we turned on the motor the pendulum mass did indeed move out into a big circle, but it didn&#8217;t stay there! Instead the circle slowly shrank until the bead was hanging almost straight down, then grew again to a big circle, then shrank again, and so on. This was the second, even less anticipated result from the lab. I still don&#8217;t have a good explanation for it. Am I getting some sort of beating between the natural period of the pendulum and the forced rotation? I think I&#8217;ll have to play around with the setup this weekend to see the effect of different variations. Some things I plan to play with include</p>
<ul>
<li>using a heavy weight for the mass, instead of a tiny one.  Originally, I had thought the I would need to allow the mass to pass through the gap in the photo interrupter, and I didn&#8217;t want to risk damaging it. But now I see that I can measure the period using the beam, so the mass can be larger.</li>
<li>adjusting the length of the string, to change the natural period of the pendulum.</li>
<li>adjusting the speed of rotation.  It would be nice to have a real slow rotation, so that I could do a decent measurement with a long string.</li>
</ul>
<p>Question for the physics people who read my blog: have any of you done the circular pendulum experiment in class?  Are there some things I should have known about to make this work better? Do you have an explanation for why I got such a varying amplitude in the size of the circle with the short pendulum? Will the long string with a fairly fast motor always produce nice nodes and antinodes, or did I get lucky on the two speeds I tried?</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/ap-physics/'>AP physics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/circular-pendulum/'>circular pendulum</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/g/'>g</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/gravity/'>gravity</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/high-school/'>high school</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/newton/'>Newton</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/physics/'>physics</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3339/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3339/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3339/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3339/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3339/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3339/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3339/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3339/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3339&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Student loans as indentured servitude</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/13/student-loans-as-indentured-servitude/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/13/student-loans-as-indentured-servitude/#comments</comments>
		<pubDate>Fri, 13 Jan 2012 18:03:33 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[debt]]></category>
		<category><![CDATA[indentured servitude]]></category>
		<category><![CDATA[student loan]]></category>
		<category><![CDATA[student loan debt]]></category>

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		<description><![CDATA[AAUP has recently published an article by Jeffrey J. Williams, Academic Freedom and Indentured Students, which makes a clear case for a view I&#8217;ve held for a while: that student loan debt is the functional and moral equivalent of indentured servitude. The idea is simple: students acquire enormous debt in the hopes of getting a [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3335&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>AAUP has recently published an article by Jeffrey J. Williams, <a href="http://www.aaup.org/AAUP/pubsres/academe/2012/JF/Feat/will.htm">Academic Freedom and Indentured Students</a>, which makes a clear case for a view I&#8217;ve held for a while: that student loan debt is the functional and moral equivalent of indentured servitude.</p>
<p>The idea is simple: students acquire enormous debt in the hopes of getting a better life, but they are required to labor for many years to repay that debt.  The main differences from indentured servitude are that the debt-holder doesn&#8217;t guarantee the existence of a job that will repay the debt, the student loan period lasts much longer than indentured servitude did, and indentured servitude is now illegal.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/debt/'>debt</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/indentured-servitude/'>indentured servitude</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/student-loan/'>student loan</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/student-loan-debt/'>student loan debt</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3335/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3335/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3335/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3335/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3335/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3335/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3335/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3335/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3335&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Codecademy Code Year</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/11/codecademy-code-year/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/11/codecademy-code-year/#comments</comments>
		<pubDate>Thu, 12 Jan 2012 03:40:06 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[computer science]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[online education]]></category>
		<category><![CDATA[programming]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3332</guid>
		<description><![CDATA[Codecademy is encouraging people to learn to program in 2012, and they are offering interactive lessons in learning JavaScript.  They describe it as a &#8220;beginner-friendly programming language&#8221;, which is not the reaction I or my son has to the language, but it is easy to do web-based lessons for, because (almost) every browser comes with [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3332&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p><a href="http://www.codecademy.com/codeyear/week/1">Codecademy</a> is encouraging people to learn to program in 2012, and they are offering interactive lessons in learning JavaScript.  They describe it as a &#8220;beginner-friendly programming language&#8221;, which is not the reaction I or my son has to the language, but it is easy to do web-based lessons for, because (almost) every browser comes with a JavaScript interpreter.</p>
<p>I wonder how many people will sign up for Code Year, and how many will make it through the year.</p>
<p>I&#8217;m curious about the pedagogy of the Codecademy lessons, but not curious enough to sit through the slow pace of interactive lessons on stuff I either already know or am not interested in learning.  I&#8217;d be interested to hear reactions from anyone who is in the intended audience (that is, complete novices at programming who want to learn JavaScript).</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/computer-science/'>computer science</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/online-education/'>online education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/programming/'>programming</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3332/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3332/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3332/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3332/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3332/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3332/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3332/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3332/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3332&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<slash:comments>28</slash:comments>
	
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		<title>NSF &#8220;clarifies&#8221; Broader Impacts</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/10/nsf-clarifies-broader-impacts/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/10/nsf-clarifies-broader-impacts/#comments</comments>
		<pubDate>Wed, 11 Jan 2012 05:08:53 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[borader impacts]]></category>
		<category><![CDATA[funding]]></category>
		<category><![CDATA[National Science Foundation]]></category>
		<category><![CDATA[NSF]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3326</guid>
		<description><![CDATA[Since 1997 NSF has required that all grant proposals be evaluated on two dimensions: Intellectual Merit and Broader Impacts. Intellectual Merit has always been clear to grant writers and grant reviewers (though they often disagree about the merits of any particular proposal).  &#8220;Broader Impacts&#8221; has always been rather murky with different grant writers and grant [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3326&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>Since 1997 NSF has required that all grant proposals be evaluated on two dimensions: Intellectual Merit and Broader Impacts.</p>
<p>Intellectual Merit has always been clear to grant writers and grant reviewers (though they often disagree about the merits of any particular proposal).  &#8220;Broader Impacts&#8221; has always been rather murky with different grant writers and grant reviewers interpreting it in incompatible ways.  It has also been very difficult to evaluate whether &#8220;Broader Impacts&#8221; have been achieved by a funded project.</p>
<p>To try to clarify things, NSF just approved a report titled <em>National Science Foundation’s Merit Review Criteria:</em><em> Review and Revisions</em><em> December 14, 2011</em>, subject to final edits.  Unfortunately, they have not put the report on their own web site yet, so I had to get a <a href="http://news.sciencemag.org/scienceinsider/MR%20Report%20Final%201_4_2012_ln.pdf">copy from scienceinsider</a>.  After reading the report (the body, not the hundreds of pages of appendices), I&#8217;m at least as confused as I was before about what the h*** NSF expects for Broader Impacts.</p>
<p>It seems that the guidance they offer is pretty much limited to one page:</p>
<blockquote>
<h4><em>Merit Review Criteria</em></h4>
<p><em>When evaluating NSF proposals, reviewers should consider what the proposers want to do, why they want to do it, how they plan to do it, how they will know if they succeed, and what benefits would accrue if the project is successful. These issues apply both to the technical aspects of the proposal and the way in which the project may make broader contributions. To that end, reviewers are asked to evaluate all proposals against two criteria:</em></p>
<p style="padding-left:30px;"><em>Intellectual Merit: The intellectual Merit criterion encompasses the potential to advance knowledge; and</em><br />
<em>Broader Impacts: The Broader Impacts criterion encompasses the potential to benefit society and contribute to the achievement of specific, desired societal outcomes.</em></p>
<p><em>The following elements should be considered in the review for both criteria:</em></p>
<ol>
<li><em>What is the potential for the proposed activity to<br />
a. advance knowledge and understanding within its own field or across different fields (Intellectual Merit); and<br />
b. benefit society or advance desired societal outcomes (Broader Impacts)?</em></li>
<li><em>To what extent do the proposed activities suggest and explore creative, original, or potentially transformative concepts?</em></li>
<li><em>Is the plan for carrying out the proposed activities well-reasoned, well-organized, and based on a sound rationale? Does the plan incorporate a mechanism to assess success?</em></li>
<li><em>How well qualified is the individual, team, or institution to conduct the proposed activities?</em></li>
<li><em>Are there adequate resources available to the PI (either at the home institution or through collaborations) to carry out the proposed activities?</em></li>
</ol>
</blockquote>
<p>They deliberately avoided further clarity:</p>
<blockquote><p><em>Because of the great breadth and diversity of research and education activities that are supported by NSF, the Board has decided not to recommend a specific set of activities related to Broader Impacts, just as it would not recommend particular types of research–those decisions are best left to the PIs to describe and to the NSF to evaluate, for relevance to programmatic priorities and alignment with NSF’s core strategies for achieving its mission, as described in the NSF Strategic Plan for FY 2011- 2016 “Empowering the Nation Through Discovery and Innovation:”</em></p>
<ul>
<li><em>Be a leader in envisioning the future of science and engineering.</em></li>
<li><em>Integrate research and education and build capacity.</em></li>
<li><em>Broaden participation in the science and engineering research and education enterprises.</em></li>
<li><em>Learn through assessment and evaluation of NSF programs, processes, and outcomes.</em></li>
</ul>
</blockquote>
<p>So grant writers and reviewers are left with nothing more specific than &#8220;benefit society or advance desired societal outcomes&#8221;. Different people will have very different ideas about what societal outcomes are &#8220;desired&#8221;, and Broader Impacts will continue to be used as a blunt instrument to reject intellectually worthy proposals based on the whims of reviewers.  If there were a list of &#8220;desired societal outcomes&#8221; then it might be possible to compare proposals, but without such a list, politics, religion, and random taste prevail.</p>
<p>More likely, there is a secret list of what NSF really wants for broader impacts, which is supposed to be &#8220;understood&#8221; without ever being stated.  So far as I can tell, NSF has just said &#8220;read our minds, we&#8217;re going to judge whether you address our goals without ever telling you what those goals are&#8221;. When this is combined with NSF&#8217;s new policy of funding bunches of stuff without external review, it becomes absolutely critical that there be clarity on what the goals are.</p>
<p>I hate guessing games like this.</p>
<h6 class="zemanta-related-title" style="font-size:1em;">Related articles</h6>
<ul class="zemanta-article-ul">
<li class="zemanta-article-ul-li"><a href="http://news.sciencemag.org/scienceinsider/2012/01/nsf-tweaks-its-merit-review-rule.html">NSF Tweaks Its Merit Review Rules</a> (news.sciencemag.org)</li>
<li class="zemanta-article-ul-li"><a href="http://blogs.nature.com/news/2011/12/nsf_takes_broad_look_at_broade.html">NSF takes broad look at broader impacts</a> (blogs.nature.com)</li>
<li class="zemanta-article-ul-li"><a href="http://writedit.wordpress.com/2011/12/15/nsf-broader-impacts-broadened/">NSF Broader Impacts Broadened</a> (writedit.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://gasstationwithoutpumps.wordpress.com/2011/11/15/new-nsf-program-without-peer-review/">New NSF program without peer review</a> (gasstationwithoutpumps.wordpress.com)</li>
<li class="zemanta-article-ul-li"><a href="http://news.sciencemag.org/scienceinsider/2011/11/new-nsf-program-sidesteps-external.html">New NSF Program Sidesteps External Peer Review</a> (news.sciencemag.org)</li>
</ul>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/borader-impacts/'>borader impacts</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/funding/'>funding</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/national-science-foundation/'>National Science Foundation</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/nsf/'>NSF</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3326/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3326/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3326/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3326/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3326/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3326/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3326/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3326/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3326&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>ISCB opposes HR 3699</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/10/iscb-opposes-hr-3699/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/10/iscb-opposes-hr-3699/#comments</comments>
		<pubDate>Tue, 10 Jan 2012 23:59:52 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[funding]]></category>
		<category><![CDATA[NIH]]></category>
		<category><![CDATA[open access]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3323</guid>
		<description><![CDATA[In the post Rolling back open access, I passed on the message about the badly thought-out Research Works Act (H.R.3699),  which is intended to prohibit federal agencies from requiring public online access to grant-funded research results. The International Society for Computational Biology has sent e-mail to all its members: As many of you may be [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3323&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In the post <a title="Rolling back open access" href="http://gasstationwithoutpumps.wordpress.com/2012/01/06/rolling-back-open-access/">Rolling back open access</a>, I passed on the message about the badly thought-out Research Works Act (<a href="http://www.opencongress.org/bill/112-h3699/show">H.R.3699</a>),  which is intended to prohibit federal agencies from requiring public online access to grant-funded research results.</p>
<p>The International Society for Computational Biology has sent e-mail to all its members:</p>
<blockquote><p><em>As many of you may be aware, the U.S. House of Representatives has recently been presented with a bill called the Research Works Act (HR 3699) that threatens the current U.S. requirements of public access to federally funded research results. ISCB strongly opposes this bill. Burkhard Rost, ISCB President, and Richard Lathrop, ISCB Public Affairs &amp; Policies Committee Chair, are drafting a letter to the bill&#8217;s authors that expresses our opposition and emphasizes the importance of the <a href="http://www.iscb.org/iscb-policy-statements/literature_open_access">ISCB Public Policy Statement on Open Access to Scientific and Technical Research Literature</a> that was released in 2010. If you are a member of ISCB and have not yet signed on to our statement, you are invited to do so at your earliest opportunity via the link to current signatories from the above URL.</em></p></blockquote>
<p>I&#8217;m glad to see that the ISCB is taking action.  It would be valuable for people to write letters to their congressional representatives.  Those who are members of professional societies should write letters to the president or board of the society asking them to take action.</p>
<p>Of course, some professional societies behave more like publishing houses than like member-serving societies, and may be perfectly happy getting back the right to keep all taxpayer-paid research behind a paywall.  Has anyone gotten ACM or IEEE to recognize the importance of open access to scientific literature?</p>
<p>Note: the NIH rule does not prevent publishers from making money selling articles, as the articles don&#8217;t become open access until a year after publication, and the user interface for getting access to the publications is rather awkward.  Several journals had already adopted an &#8220;open after a year&#8221; policy before the NIH ruling took effect.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/funding/'>funding</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/nih/'>NIH</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/open-access/'>open access</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3323/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3323/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3323/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3323/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3323/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3323/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3323/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3323/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3323&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Ways to respond to literature using New York Times models</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/08/ways-to-respond-to-literature-using-new-york-times-models/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/08/ways-to-respond-to-literature-using-new-york-times-models/#comments</comments>
		<pubDate>Sun, 08 Jan 2012 21:04:42 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[1984]]></category>
		<category><![CDATA[Alice in Wonderland]]></category>
		<category><![CDATA[book report]]></category>
		<category><![CDATA[Brave New World]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[English class]]></category>
		<category><![CDATA[Left Hand of Darkness]]></category>
		<category><![CDATA[literature]]></category>
		<category><![CDATA[NewSpeak]]></category>
		<category><![CDATA[Planiverse]]></category>
		<category><![CDATA[writer's block]]></category>
		<category><![CDATA[writing]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=2981</guid>
		<description><![CDATA[Last November, the NY Times published an article about alternatives to the standard school book report for English classes: Beyond the Book Report: Ways to Respond to Literature Using New York Times Models.  I read the article then, and forwarded the link to my son, my wife (who supervises his humanities education), and my son&#8217;s [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=2981&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>Last November, the <a class="zem_slink" title="New York Times" href="http://www.newyorktimes.com" rel="homepage">NY Times</a> published an article about alternatives to the standard school book report for English classes: <a href="http://learning.blogs.nytimes.com/2011/11/10/beyond-the-book-report-ways-to-respond-to-literature-using-new-york-times-models/">Beyond the Book Report: Ways to Respond to Literature Using New York Times Models</a>.  I read the article then, and forwarded the link to my son, my wife (who supervises his humanities education), and my son&#8217;s consultant teacher.  I meant to blog about it right away, but it got buried in my over-100 draft posts of things I mean to blog about as soon as I have time.  The pointer just got forwarded to the other home-schoolers at <a href="http://www.afe.santacruz.k12.ca.us/">Alternative Family Education</a>, so it is past time for me to write this post.</p>
<p>The article offers 13 alternative assignments for the usual &#8220;book report&#8221; or &#8220;literary analysis&#8221; assignment (which I have ranted about before in posts like <a href="http://gasstationwithoutpumps.wordpress.com/2011/05/11/death-to-high-school-english-education-salon-com/">Death to high school English</a> and <a href="http://gasstationwithoutpumps.wordpress.com/2011/10/23/reluctant-writers/">Reluctant Writers</a>).  I don&#8217;t know that we will use any of them exactly, but they did help spur some thinking about some of the assignments my son has done for his &#8220;Alternative Realities&#8221; English class so far this year:</p>
<ul>
<li>description of the caste system in <em>Brave New World</em></li>
<li>sociolinguistic analysis of NewSpeak in <em>1984</em></li>
<li>extra chapter for <em>Alice in Wonderland</em>, describing her adventures in a land that looks a lot like Minecraft</li>
<li>map of Gethen, the world (or part of the world) in <em>Left Hand of Darkness</em></li>
<li>travel guide for Arde, the world in <em>Planiverse</em></li>
</ul>
<p>He has not been having the huge problems with writer&#8217;s block that he had last year.  I think that being able to craft his own style of response to each book (in consultation with his mother, who is choosing the books, discussing them with him, and giving him feedback on his drafts) has helped a lot in allowing him to keep moving on the assignments.  His consultant teacher has indicated that he needs to do six assignments each semester to get full credit for an English class, and he seems to be on track for that.  We&#8217;re thinking of a dramatic reading (with sound effects) for the 6th project.</p>
<p>He&#8217;s been doing writing in his other classes also.  His time-line for history class requires a lot of one-paragraph summaries, he&#8217;s done one lab report for physics (I should require a couple more), and he has been doing fairly detailed write-ups for his calculus homework sets (the Art of Problem Solving faculty provide feedback on the writing, so his math writing has improved enormously since he started precalculus with them last year). His science fair and robotics projects have not generated much writing yet, but he&#8217;s been keeping notes in his science-fair lab notebook and has a draft of the general introduction to his science fair project, so I&#8217;m hopeful that he&#8217;ll produce a decent report this year without too much prodding.  (His previous science fair reports are good, but took a lot prodding to get him to complete.)</p>
<p>Overall, I think that the writing he has done this year has been good for him and has not been much different in quantity than if he had been in school.  He&#8217;s felt less pressured about it, because each writing project has been one he has chosen, or at least agreed is a necessary component of something he has chosen.  We&#8217;ll see whether he can do the writing needed for the Shakespeare class he is taking this spring (in preparation for a trip to Ashland), or whether the prompts there turn out to be too inflexible for him.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/1984/'>1984</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/alice-in-wonderland/'>Alice in Wonderland</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/book-report/'>book report</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/brave-new-world/'>Brave New World</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/english-class/'>English class</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/left-hand-of-darkness/'>Left Hand of Darkness</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/literature/'>literature</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/newspeak/'>NewSpeak</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/planiverse/'>Planiverse</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/writers-block/'>writer's block</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/writing/'>writing</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/2981/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/2981/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/2981/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/2981/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/2981/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/2981/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/2981/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/2981/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=2981&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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		<title>Preclass learning</title>
		<link>http://gasstationwithoutpumps.wordpress.com/2012/01/06/preclass-learning/</link>
		<comments>http://gasstationwithoutpumps.wordpress.com/2012/01/06/preclass-learning/#comments</comments>
		<pubDate>Sat, 07 Jan 2012 00:25:06 +0000</pubDate>
		<dc:creator>gasstationwithoutpumps</dc:creator>
				<category><![CDATA[home school]]></category>
		<category><![CDATA[education]]></category>
		<category><![CDATA[high school]]></category>
		<category><![CDATA[science education]]></category>
		<category><![CDATA[physics]]></category>

		<guid isPermaLink="false">http://gasstationwithoutpumps.wordpress.com/?p=3312</guid>
		<description><![CDATA[In my recent post NPR reports on peer instruction, I conjectured that a lot of the gains of Mazur&#8217;s peer instruction came from getting the students to interact with the material before class.  Although there may well be other aspects of Mazur&#8217;s pedagogy that are as important or more important, many teachers are looking at [...]<img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3312&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></description>
			<content:encoded><![CDATA[<p>In my recent post <a title="NPR reports on peer instruction" href="http://gasstationwithoutpumps.wordpress.com/2012/01/02/npr-reports-on-peer-instruction/">NPR reports on peer instruction</a>, I conjectured that a lot of the gains of Mazur&#8217;s peer instruction came from getting the students to interact with the material before class.  Although there may well be other aspects of Mazur&#8217;s pedagogy that are as important or more important, many teachers are looking at how to get students to read and think about material before class.  It is much more productive for a teacher to be clearing up confusions in the mind of someone who has already started thinking about a problem than trying to get them started from nothing.</p>
<p>Joss Ives, on <a href="https://learnification.wordpress.com">The Science Learnification blog</a> had a nice post on this today, <a href="https://learnification.wordpress.com/2012/01/06/learning-before-class-strategies-quick-update/">Learning Before Class Strategies – Quick Update</a>, which included pointers to  other blog posts and articles by various people about pre-reading.</p>
<p>Unfortunately, the data from Joss&#8217;s own class do not show any correlation between completing &#8220;pre-lecture and checkpoint assignments&#8221; and the final exam scores.  It is not clear whether this means that the pre-reading was not effective, or whether the scoring on the pre-class assignments was measuring the wrong thing.  It was an effort measure, but it may well be that the students were just going through the motions of doing the pre-reading, and not actually engaging with the material.</p>
<p>Or maybe students were only reading the material once, in which case it may not matter much whether it is before or after the class in which the material is &#8220;covered&#8221;.</p>
<p>My own experience trying to learn physics this fall with my son is that I learn very little from reading the book—I have to work several exercises to get the ideas firmly into my head.  The book (<a href="http://matterandinteractions.org/">Matter and Interactions</a>) has several places where the reader is supposed to stop and think about an example, but I rarely find myself doing so.  Only when I&#8217;m working a problem &#8220;for real&#8221; do I actually think in much detail about the models and formulas.  Sometimes the formulas stick in my head without much effort, but other times not (I particularly have problems with arbitrary constants like <img src='http://s0.wp.com/latex.php?latex=1%2F%284%5Cpi%5Cepsilon_0%29&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='1/(4&#92;pi&#92;epsilon_0)' title='1/(4&#92;pi&#92;epsilon_0)' class='latex' />).</p>
<p>So perhaps the secret is not pre-reading, but discussing homework problems after students have struggled with them a bit.  That is the approach our home-schooling class is taking, where we spend our 2 hours a week either comparing solutions to homework problems (and clarifying any confusion brought up by the problems) or doing a lab.  I find the lab classes more fun, though they take more prep time, as I have to design and build or buy whatever equipment we need.  I just got a pair of &#8220;<a href="http://www.sparkfun.com/products/9299">photo interrupters</a>&#8221; from Sparkfun, together with breakout boards that I hope we&#8217;ll use next week for timing the period of a circular pendulum to do Newton&#8217;s measurement of <img src='http://s0.wp.com/latex.php?latex=g&amp;bg=ffffff&amp;fg=000000&amp;s=0' alt='g' title='g' class='latex' />.</p>
<p>Comparing solutions has turned out to be useful, even when we have all made the same mistake, because we talk through the method and compare intermediate results as well as the final result. On one mass and spring exercise in Chapter 4, I noticed that we had all left out the force due to gravity, which happened to matter for that exercise.  We re-worked the exercise in class, and got a slightly different solution.</p>
<br /> Tagged: <a href='http://gasstationwithoutpumps.wordpress.com/tag/education/'>education</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/high-school/'>high school</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/physics/'>physics</a>, <a href='http://gasstationwithoutpumps.wordpress.com/tag/science-education/'>science education</a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gocomments/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/comments/gasstationwithoutpumps.wordpress.com/3312/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godelicious/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/delicious/gasstationwithoutpumps.wordpress.com/3312/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gofacebook/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/facebook/gasstationwithoutpumps.wordpress.com/3312/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gotwitter/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/twitter/gasstationwithoutpumps.wordpress.com/3312/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/gostumble/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/stumble/gasstationwithoutpumps.wordpress.com/3312/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/godigg/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/digg/gasstationwithoutpumps.wordpress.com/3312/" /></a> <a rel="nofollow" href="http://feeds.wordpress.com/1.0/goreddit/gasstationwithoutpumps.wordpress.com/3312/"><img alt="" border="0" src="http://feeds.wordpress.com/1.0/reddit/gasstationwithoutpumps.wordpress.com/3312/" /></a> <img alt="" border="0" src="http://stats.wordpress.com/b.gif?host=gasstationwithoutpumps.wordpress.com&amp;blog=13967059&amp;post=3312&amp;subd=gasstationwithoutpumps&amp;ref=&amp;feed=1" width="1" height="1" />]]></content:encoded>
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			<media:title type="html">gasstationwithoutpumps</media:title>
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