Bridget Duffy at Gel 2008 from Gel Conference on Vimeo.

• Academic Earth
• Free Science Online
• Best Documentaries Blog
• Google Tech Talks
• TED

• Robert Morrison and Frank Lambert (two papers, pay special attention to the first half of the second paper)
• Eric Mazur on Classroom Clickers
• Ira Flatow on the NPR talking with Lei Boh from Ohio State
• A paper from Harvard Med on Live vs Recorded lectures from Harvard
• Edward Tufte's essay The Cognitive Style of PowerPoint"
• A review article by Johnathon Sweller, who works on cognitive load and considers PowerPoint a disaster.
• These last two are because I think to understand why your students are they way they are, you need to get some different perspectives on where they come from
  • The Underground History of American Education by John Gatto
  • Why are nerds so unpopular? by Paul Graham

• In the 1970s, Uri Triesman found disadvantaged youth did better in calculus when they worked in groups. Selected works:
• Carney et al acknowledged in 2004 that this was a problem and, in a special article in JAMA, called for an epidemiological approach to the problem.
• My own survey of my classmates, to assess the time value of study habits according to self-reported performance. This is a quick and dirty thumbnail sketch that I *really* need to follow up on. Unfortunately, it is the best data I know of, of its kind. If anyone knows of something similar, please let me know.
• Noel Entwistle and a related group in the UK have done some very interesting work, but why aren't students *taught* these things, explicitly () (I should also qualify that it's been an uphill battle getting quantitative results)
• Ference Marton is a Swedish educational psychologist. Disentangling Marton and Entwistle in the literature is an exercise left to the reader.
• I would also recommend John Pelley, though I believe his thought process is still too heavily influence by the lecture-oriented focus chucking content into standard sizes regardless of the natural size of the topic. Wikipedia, however, uses naturally found sizing of chunks. They are as long as they need to be, infinitely malleable, and infinitely linkable; the linking is really what puts Pelley's customized mind-mapping strategies and into the same class as Wikipedia.
• I have recently been experimenting with journaling my own wiki, inspired in part by Pelley. It is actually remarkably easy to install MediaWiki, the engine of Wikipedia, on your own laptop via this link (it's really a database company, but they package mediawiki as a "sample app" to see how the database performs:http://www.enterprisedb.com/products/pgdownload.do). If anyone actually wants to try this, let me know, as I have a couple of tweaks that will make life *much* easier. Here are three screenshots (Index, Random chunk of article, and the WYSIWYG editor, illustrating my custom special character palate)]]> http://nielsolson.us/Haversian/2009/02/some_current_thoughts_on_teach.php http://nielsolson.us/Haversian/2009/02/some_current_thoughts_on_teach.php Wed, 04 Feb 2009 17:23:18 -0600 $ w 14:52:53 up 19:57, 4 users, load average: 0.08, 0.05, 0.00 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT root pts/0 98.99.108.102 12:42 1:50 0.12s 0.12s -bash tadmin pts/1 24.252.72.55 14:52 0.00s 0.02s 0.02s -bash niels pts/2 70.180.123.187 14:48 0.00s 0.16s 0.02s sshd: niels [pr tadmin pts/3 24.252.72.55 14:52 10.00s 0.02s 0.02s -bash We're interested in pts/0, so we'll look up it's teletype $ ps -t pts/0 PID TTY TIME CMD 6594 pts/0 00:00:00 bash Now, if you try to close this bash session, even as root, you may be stymied, because that process actually belongs to the ssh process that spawned it. So we need to find the sshd session owned by root that immediately preceded this bash session. This will be a long list, especially if you're searching for processes owned by root. $ ps -U root ... 6590 ? 00:00:00 sshd 6594 pts/0 00:00:00 bash ... Now just kill those $ kill 6590 6594 $ w 14:52:53 up 19:57, 4 users, load average: 0.08, 0.05, 0.00 USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT tadmin pts/1 24.252.72.55 14:52 0.00s 0.02s 0.02s -bash niels pts/2 70.180.123.187 14:48 0.00s 0.16s 0.02s sshd: niels [pr tadmin pts/3 24.252.72.55 14:52 10.00s 0.02s 0.02s -bash ]]> http://nielsolson.us/Haversian/2009/01/howto_kill_an_orphaned_ssh_ses.php http://nielsolson.us/Haversian/2009/01/howto_kill_an_orphaned_ssh_ses.php Sat, 10 Jan 2009 14:58:28 -0600 1) right-click on icon ==> Properties ==> Shortcut ==> Change Icon 2) Delete shortcut and recreate from Start ==> All Programs 3) Desktop right-click ==> Properties ==> Appearance ==> Effects ==> use large icons ==> ok ==> ok, then switched back to regular size icons 4) restarted in safe mode (press F8 right after the BIOS finishes and before the normal Windows boot starts), then restarted back into normal mode 5) Used Tweak UI to rebuild icon cache and restarted 6) Resized Max Cached Icons in the registry using the Kelly's Korner VB script (this sets the Max Cahced Icons value to 12000) and restarted 7) Manually resized Max Cached Icons to 4096 with regedt32, deleted C:\Documents and Settings\{user name}\Local Settings\Application Data\Iconcache.db and restarted 8) Manually resized Max Cached Icons to 8192, deleted C:\Documents and Settings\{user name}\Local Settings\Application Data\Iconcache.db, and restarted 9) If all else fails, by this point you surely have cleaned up any issues with the icon cache and you may be prevented from modifying the unfortunately botched icons on some .exe files (Photoshop, Illustrator, InDesign, and Opera were some of the ones I just couldn't fix). What finally fixed them was to download the free utility IconExtract, and manually extract the icons from the .exe files and save them to a new folder (I recommend creating the path C:\usr\share\icons for this task). Then you have to go back to step 1 and reset each icon manually.]]> http://nielsolson.us/Haversian/2009/01/fixing_broken_icons_in_windows.php http://nielsolson.us/Haversian/2009/01/fixing_broken_icons_in_windows.php Sun, 04 Jan 2009 12:09:01 -0600 Bluehost's cpanel can create cnames, it just doesn't call the whole process by its real names. Let's say you want to use Google Apps. 1) visit http://google.com/a/ to get your account set up. 2) To verify your domain, Google gives you a code and you can either make an html file or make a CNAME entry. Copy the code Google gives you. 3) Go to bluehost's cpanel 4) subdomains 5) paste that code into the subdomain field 6) make up a directory name, you'll never use it. foo is a perfectly good name. 7) click "Create" 8) "googlefffffffffsplat37493.yourdomain.com has been created!" now go back. 9) click "Manage Redirection" 10) On the left is your subdomain. In more standard BIND parlance, this is the "Record-Key" part of your CNAME. The "Value" part, where you want to redirect to, is um, where, you, want, to, redirect, to. In the google apps verification example, you would type in google.com. Once you're verified, to set up gmail for your domain, you would set up a subdomain "mail", pointing to some random, made up directory name, then "Manage Redirection" to point to google.com/a/yourdomain.com http://nielsolson.us/Haversian/2008/12/how_to_make_a_cname_dns_entry.php http://nielsolson.us/Haversian/2008/12/how_to_make_a_cname_dns_entry.php Sat, 06 Dec 2008 19:47:44 -0600 Angela Morelli, asked me by email why we understand numbers and graphs differently. A revised and sources-cited version of my response is below.

  People interpret numbers and graphs differently because they are handled differently in the brain. Numbers are generally handled by the verbal linguistic system and graphs are handled by both the non-verbal linguistic system and the limbic system. The bit rate of the visual system is about 10 million bits/second (see Tufte's original thread). The rate of reading, listening, braille, typing, maxes out at around 150-400 words per minute. To understand how this works, and provide a foundation for further reading, a *very* brief review of the relevant neuroscience seems in order.

  Visual processing begins in the retina with some very simple edge definition. Further edge definition occurs where the neurons of the optic nerve enter the brain at the lateral geniculate nucleus. The neurons synapse and new neurons run in the optic radiations from the LGN to the banks of the calcarine sulcus, where further edge definition and integration occurs. The calcarine sulcus is at the very posterior part of the cerebrum and represents the first time the visual information enters the cerebral grey matter. From there, the final elements of subconscious analysis and pattern recognition occur in the lingual gyrus and cuneus, which sort of wrap around the banks of the calcarine sulcus like concentric rings (heavily folded, of course). Everything up to and including this point is essentially image processing.

  Conscious recognition starts to occur in the inferotemporal region, Brodmann's areas 37 and 7a. Lesions to these areas lead to what are called agnosias. Oliver Sacks' The Man Who Mistook His Wife for a Hat has a good example of an agnosia. In fact, most of the back half of the cerebrum (abaft your ears) that isn't involved in basic visual perception is involved in this kind of unimodal association. The other major exception is the angular gyrus and Wernicke's area.

  Once the basic conversion to symbolic information occurs, information is routed based on type. Basic numeracy is handled by Brodmann's area 39 in the angular gyrus of the parietal lobe, just slightly above Brodmann's area 37 where the numbers were recognized as numbers. The syntactic region of the brain, Wernicke's area, exists very close by, and can be considered to involve the angular gyrus. A stroke to Wernicke's area leads to expressive aphasia. The patient has access to their entire vocabulary and will speak words clearly, but can't understand and can't compose syntactically correct thoughts. This is commonly described as a "word salad". Wernicke's area is where mathematical training or computer science training trains new syntactic structures. A physicist, in some ways, can think thoughts a non-physicist can't. If Noam Chomsky's syntactic structures exist, they are mainly constructed in Wernicke's area. Now, Wernicke's area is still in the back half of the brain. It is evolutionarily older than Homo sapiens. And, indeed, apes and even dogs, rats, cats, and insects can construct syntacticly different sequences of sounds.

  Where we really start to diverge from other species is in Broca's area, which structurally lies in the relatively new prefrontal cortex and consists of the Pars triangularis and Pars opercularis. Functionally, Broca's area contains the dictionary. A person with a stroke in Broca's area can, with great difficulty, construct sentences, but they have profound word-finding problems which get worse with stress. And they're always stressed out because they can't find the word! Between Wernicke's area and Broca's area is the arcuate tract, a superhighway of axons committed to carrying information between the neurons of Wernicke's area and Broca's area. Damage to the arcuate tract results in a person who can understand and can speak, but can't hear what you say and then formulate a reply. In higher math, it is the left-sided verbal linguistic system that is involved in equations. In basic number recognition, it is simply the angular gyrus that is involved. This whole system is essentially verbal and exists on the left side. A non-verbal, musical, spatial, temporal, inflection-oriented corollary system exists on the right side.

  Someone with a right-sided stroke can communicate, but may have inappropriate responses because they can't understand, interpret, or compose the "how you say it". They also have difficulties interpreting space and, perhaps, time, as they tend to have attention disorders. Interestingly, mathematicians are commonly interested in music and often find spatial expressions of their mathematics particularly appealing, suggesting a high degree of integration between their verbal and non-verbal language centers. And, similar to the syntactic function of Wernicke's area, a musician can compose syntactic structures a non-musician may have a hard time understanding.

  As an aside, I am inclined to wonder if general intelligence is an emergent property of our neurons in a way that is similar to how a Turing complete programming language can emerge from Church numerals and lambda calculus. One could think of a neuron as an atom, two neurons connected by a synapse as a list, and every neural synapse is an additive function activated by an action potential.

  Regardless of how many bits go between Broca's area and Wernicke's area over the arcuate tract, that word-per-minute limit is still representative of how fast people can cogitate about abstract things like numbers. Obviously 150-400 words per minute is much slower that 10 million bits/second. However, the trained mind can handle numbers faster than the untrained mind, and scanning a table of numbers for the high and low and getting a feel for the median and the nature of the distributions and the relationships between variables can be done quite quickly without cogitating too explicitly about each number. One need not advance every number to the level of free will to appreciate that some are bigger than others.

  Outwardly the difference between computer graphics processors and general purpose central processors is very similar to the difference between the visual system and the verbal or non-verbal linguistic systems. At the nVidia08 conference, Mythbusters provided a very nice demonstration of the difference between manipulating a single-threaded general processor (analogous to the linguistic system composed of Broca's area, Wernicke's area, and the arcuate tract) to render an image, and a function-specific system like a graphics processor or the visual system. While faster general processors are desirable, their power is not in their speed. Their power is in their generality, their ability to deal with any abstract issue and, potentially, make value judgments and exert free will. The mythbusters's CPU illustration, for example, could also be used to pick things up, or whatever else a robotic arm can be made to do.
  
  

  Judgment, free will, and risk analysis occur on two levels. Judgment and free will occur in the very newest part of the cerebrum, the anterior cingulate gyrus, roughly Brodmann area 24. Recent findings suggest this is the last part of the brain to mature, at about the age of 25. I guess the car insurance companies know what they're talking about :-) Risk analysis can occur in this area, but, as we all know, the average bee can also conduct risk analysis. This reflexive risk analysis occurs in the limbic system, part of the reptilian brain that underlies our newer cerebrum. marketeers like graphs with a positive slope because society teaches us over and over the a positive slope is good, income-positive, growing, whatever. It's the repetitive association with primal desires that causes the positive slope to be imprinted on the reptilian brain. Me like up and right! Can I has cookie? Valuations that are repeated, over and over, are more likely to be imprinted, branded in the limbic system's primordial type of memory. Commercial television really is all about holding your eyes still while they spray your brain with advertising. Imprinting those brands on the limbic system. Over and over. Until the reptilian brain learns. The great thing about this, for marketeers, is that the reptilian brain keeps us alive in a lot of situations so it tends to get privileged access to information so it can respond very quickly, when necessary, or at least when certain preconditions are met. Marketeers have leveraged those preconditions to train the imprinted, branded, conditioned reptile to pick things up off the shelf before the human brain intervenes.

  What we have then is an input system, the visual system, that provides input to multiple analytical systems. We are, at a minimum, a multi-core processor. Understanding numbers and thinking about math and interpreting graphics and making value decisions requires the newest and most complex parts of our brain, but there is a very real possibility of sending the information to the wrong system, the reptilian system. The association (positive slope)==(good), in any human who grew up in modern society, can be safely assumed to be imprinted in the reptilian brain. Unfortunately, even very educated and successful people may be are usually susceptible to such simple tricks.

  So, making graphics to represent numbers can be tricky work, and society has rewarded ET and others for grappling with the problem. There are some books on how to think about these problems :-) If you want to evoke things that the reptile values, like hunger and fear, then activate the reptile. If you want things that are assigned by prefrontal centers, like credibility, reputation, and respect, then you should try to activate the prefrontal centers, and providing numerical information is one way to do that. If you need graphs because there are too many numbers, then you should make sure those graphs activate the non-verbal linguistic system: they should carry a fair bit of information, describe multiple variables,, prompt further decision-making by the prefrontal cortex, cite your sources, etc.
  
  ¹The neuroanatomy for this post was checked against DE Haines, Fundamental Neuroscience for Basic and Clinical Applications, 3rd Ed, Elsevier 2006, pp 518-522.]]> http://nielsolson.us/Haversian/2008/11/why_do_we_think_about_numbers.php http://nielsolson.us/Haversian/2008/11/why_do_we_think_about_numbers.php Natural Science Sat, 08 Nov 2008 14:17:47 -0600 I just ordered a coffee at Starbucks. I always order "a medium cappuccino for here, in a ceramic cup". It's redundant, but I want to make sure I don't use a paper cup. So today the girl took out a paper cup, after I told her three times I wanted a ceramic cup, she wrote my order on the paper cup, dropped it in the ceramic cup, and gave it to the barista, giving me a look, like "You didn't expect me to be *that* clever, did you, silly customer?" Why not just tell the barista "medium cappuccino"? http://nielsolson.us/Haversian/2008/10/starbucks_fail.php http://nielsolson.us/Haversian/2008/10/starbucks_fail.php Social Science Sat, 25 Oct 2008 16:31:06 -0600 The Congress shall have power to . . . [do a whole list of things, including] . . . promote the progress of science and useful arts, by securing for limited times to authors and inventors the exclusive right to their respective writings and discoveries; Amendment I:

  Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press . . .

  Just in case anyone obsessed with their "intellectual property rights" missed it. If you're not promoting the progress of science or useful arts, your attempts to restrict freedom of the press are in violation of the spirit of the Constitution.]]> http://nielsolson.us/Haversian/2008/09/copyright_in_the_constitution.php http://nielsolson.us/Haversian/2008/09/copyright_in_the_constitution.php Social Science Mon, 22 Sep 2008 19:56:27 -0600 There are two basic ways electromagnetic radiation can transfer energy to a biological system to cause damage: thermal and molecular. Thermal energy is cooking, heating, sunburns. You need a large amount of energy and it's typically in the range of visible light (in order: radio -- infrared -- visible -- ultraviolet -- x-ray/cosmic ray/nuclear). The peak instantaneous power output from any cell phone is 3.6 watts; the average power output is substantially lower. The capacity of a Lithium-polymer battery is about 300 Watt*hours per liter (Wh/L); a cell phone battery is about 6 milliliters, so the average cell phone battery has a capacity of about 2 Watt*hours. Given that people typically charge their phone once a day and probably talk between 30 minutes and 1 hour per day, plus the constant discharge rate required by the phone to check in with the network on occasion. Let's assume the energy of the talking-for-an-hour and not-talking-for-23-hours demands are roughly equivalent. That is you expend no more than 1 watt on talking, and one watt on being ready to talk. Assuming you plug in your phone before it dies, you're virtually certain the power output during that hour is less than 1 Watt, which agrees with the wikipedia article below. Let's say it's 0.8 watts. More than half of that is radiated away from you. The geometry might be an interesting exercise for solid geometry students. But let's say the flux through your head is 50%, we're now talking 400 mW for one hour, probably broken up into several chunks, but let's assume you just blast your head for one hour straight. And, remember, the intensity decays at a rate proportional to r^2. Ignoring the attenuation due to scattering induced by hair, molecular cell membranes, proteins, extracellular elements, like your bony skull, etc, we can model the head as a bag of water. That's pretty much the worst case scenario. So what happens to that 400 mW in your bag-of-water head? The real permittivity of liquid water at 25 C to light at 827 MHz is about 78.27 (a unitless number) and the imaginary component of permittivity is about 2.00*, so the absorption coefficient, alpha, is about 7x10^15 Watts per meter. That is, the power attenuation per unit length is 7,000,000,000,000,000 watts per meter. That 400 milliwatts is absorbed by the first few layers of skin and dissipated spherically as black body radiation, just as though you were sitting outside in the sun and your scalp got warm. You expose your brain to more black body radiation taking a 10 minute walk on a sunny day than you do listening to a cell phone. Now, let's assume your head is a vacuum and that cell phone radiation got clean through many more times flesh than it actually takes (see above paragraph). Molecular damage occurs when a photon is of just the right frequency to snap a bond and happens to run in to just that kind of bond. These interactions are almost universally at wavelengths much much shorter (higher frequency) than thermal radiation. Ultraviolet light, which has wavelengths in the nanometers, about the length of molecular bonds, is famous for this. It actually takes very special biological molecules to capture visible light, which is at 500 to 700 nanometers. Mainly the porphyrin rings in clorophyll and blood. In any case, it is still dose dependent. Cell phones transmit between 824 and 829 Megahertz, roughly in the VHF radio range, rather deep into the radio spectrum, with a wavelength of about a meter. Roughly speaking, you would need a homogenous structure (like metal, salt, or a body of water) at least 0.25 meters in length to expect any interaction. While DNA may be longer than 0.25 meters, it is not stretched out inside a cell: there are no intracellular nuclei that are 0.8 feet long to accomodate such a stretched out piece of DNA. Here is a fairly good article on the issue if you want stats; if you find the part about mobile phones and cancer, you'll see that in large population samples studied over decades, no evidence of increased risk has been found. http://en.wikipedia.org/wiki/Mobile_phone_radiation_and_health *Permittivity values interpolated from CRC Handbook of Chemistry and Physics, 81st Edition, CRC Press, 2000. I just rough-guessed between the published values (freq, real, imaginary): (500MHz, 78.31, 1.90) and (1000GHz, 78.16, 3.79) http://nielsolson.us/Haversian/2008/09/simple_models_of_cell_phone_ra.php http://nielsolson.us/Haversian/2008/09/simple_models_of_cell_phone_ra.php Medicine on the Web Sun, 21 Sep 2008 14:43:48 -0600 ]]> http://nielsolson.us/Haversian/2008/08/uss_nimitz_cvn_68_transiting_t.php http://nielsolson.us/Haversian/2008/08/uss_nimitz_cvn_68_transiting_t.php Navy Sun, 03 Aug 2008 14:06:38 -0600 Journal_Club and surgery.]]> http://nielsolson.us/Haversian/2008/07/journal_club_and_surgery_subre.php http://nielsolson.us/Haversian/2008/07/journal_club_and_surgery_subre.php Wed, 23 Jul 2008 00:42:15 -0600