Useful and freaky

OK, sometimes a thing is just plain wierd, grabs you viscerally and makes you say "huh?"... and sometimes a thing is a useful manipulation of visual imagery that allows you to instantly grasp a very complicated quantitative concept. And sometimes, it's both!

There are a number of examples of anatomical homunculi (pleural of homunculus, Latin for "little man"), used to illustrate the relative sensory and motor real estate in the brain assigned to the various body parts. The hands and face require much more precise control of movement than, say, the legs. These areas also have much better sensory discrimination. Because of this, they require more motor and sensory neurons in the brain, and therefore they are proportionally bigger in the homunculus.

This concept has been around for decades, but usually just as a crude drawing. The natural history museum in London has two terrific three dimensional renderings of these little guys- here is the motor version, and here is the sensory version.


For those of you who google reflexively, the term homunculus has other usage as well. Initially a homunculus was a legendary manmade assistant to alchemists (starting in 16th century Switzerland with the infamous Paracelsus). Various recipies for making these creatures were described, usually involving human semen. Later, the concept was used to visualize a miniature human inside each individual sperm, in one of the early theories of conception.

Interesting, huh? Sure beats sifting through votes in Ohio like all the other blggers...

The title of this post is the title of this post, which is...

Yeah, yeah... I know... "what happened to all the blogging, Mike? Bored already..?" Well I was out of town, and then I got busy with work, and then there's a lot of stuff to do to get ready for the holidays, and OK I'm finished now.

Here's something that is both fun and is NOT a political diatribe. Recursion!

What is recursion? Well, it's something that is recursive. Hehehe...that's a little linguistics joke there. Here's another one, by Andrew Plotkin, and cited in the recursion entry in wikipedia.com: "If you already know what recursion is, just remember the answer. Otherwise, find someone who is standing closer to Douglas Hofstadter than you are; then ask him or her what recursion is."

Recursion has also been cited by the patron saint of geek humor. Dilbert once referred to joining TTP, which stands for "The TTP Project".

Anyway, recursion may be a difficult mathematical construct, but it makes for very amusing Web thingies. Here is one. And here is how to make one of these (thanks to Dave Pescovitz (BoingBoing.net), who seems to have found this on Cliff Pickover's Reality Carnival). And finally, take a look at this beautiful recursive cruise through some very interesting artwork (hint: pick the "flash" option).