American Scientist presents an interesting proposal in its Macroscope column this month. The authors want to explicitly redefine Avogadro's number (~6.022 × 10²³, as you may remember from physics) to be a specific integer.

I remember learning that this number represented a mole, the number of molecules of water in a gram. It turns out, of course, that this depends on the definition of a gram. At the moment, the gram is defined by a specific chunk of metal held in a vault somewhere in France. This chunk of metal (Le Gran K, according to the article) is changing over time (due to handling, cleaning, etc), so the actual definition of a gram is changing, as is (consequently) Avogadro's number. Redefining Avogadro's number to be a constant would remove the Système International's dependence on this physical artifact.

I know I'm supposed to be studying, but this is too funny, and physics related, so it's ok. I stumbled upon this site that reviews the best and worst (mostly worst) representations of physics in the movies. Very funny. It includes a movie phyics rating system. The earth catasrophe movies seem to fair the worst, as is to be expected if you've ever seen one.

Jim Crooks pointed me to an experimental group who have created bizarre things from cornstarch. Their techniques are simple: a basic solution in a drum, oscillated at a specific frequency and amplitude. Then they inject puffs of air, and simple holes are formed in the liquid. But at certain frrequencies and amplitudes, the holes will persist indefinitely. And at certain frequencies, the holes generate creepy, writhing structures that dance across the entire surface of the drum.

The linked site contains a movie (you should watch it all the way through to the end!) and a pdf detailing the specifics of their experimental apparatus and their findings.

Some fun links from yesterday's NYTimes:

• Is Time Travel Possible?
• Reality influenced by others?
• Best of web art