Monthly Archives: June 2008

But Why is it so Hot in the Okefenokee?

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Evaporative (Swamp) Coolers

I was discussing this with our resident mechanical systems guru just a few days ago — really hot, humid weather had some of the HVAC systems gasping, and if you can’t reject heat anymore, the system stops cooling (a basic bit of thermodynamics lost on some people). He was reminiscing about when he could use swamp coolers, in the southwest part of the US.

Evaporation works as a cooling mechanism, which is why we sweat when we get hot, because the molecules that go to the gas phase take more than their share of energy with them — somewhere around 2300 J/g, depending on the temperature. And the energy to change that one gram of water’s temperature by a single degree is 4.18 J, so if I have 100g of water and lose one gram to evaporation, the remaining water will cool by 5.5ºC! (Assuming, of course, no other heat transfer to warm it back up. But hey, we’re physicists. Our cows are spherical and inclined planes frictionless)

You can use this cool things off without ice — put the beverages in a canvas bag and hose it down and let evaporation do the work (the canvas holds on to the water, so it doesn’t just run off). It won’t make the beer frosty, but as long as the water can evaporate, it’ll cool it off some. (rule of thumb — if your cold beverage containers tend to “sweat,” then this probably isn’t going to work very well. But here’s another trick for you, from my navy days aboard the USS Disneyworld — to keep that pitcher cold, fill a tall glass or cup with ice and let it float in the pitcher. Cold but no dilution.)

You're So Analytic

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Sometime you have to let art flow over you. But apparently, this is not one of those times. How To Win the New Yorker Cartoon Caption Contest

Should you make a pun or, perhaps, create a visual gag about a cat surreptitiously reading its owner’s e-mail? Neither. You must aim for what is called a “theory of mind” caption, which requires the reader to project intents or beliefs into the minds of the cartoon’s characters.

I’ve entered this exactly once. To me, caption contests are backwards. I have an idea and draw a situation to match — the trick is distilling an allegedly funny idea into something that I can draw in a single-panel cartoon.

The “theory of mind” approach lets you take a single point in time — the utterance of the whatever’s in the caption — and force the reader to construct what has just happened (and sometimes the drawing does that anyway), but that and the common experience the reader must have is as much of a setup as you get. I’ve had people tell me a joke and suggest that it would make a funny cartoon, and I have to point out it took 45 seconds of talking to set up the punchline. It’s rare that that will lend itself to a single-panel cartoon.

via Cosmic Variance

From the Files of Doctor Obvious

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The Bikini Effect

[M]en alternately fondled t-shirts and bras (which were not being worn during the test). After touching the bras, men valued the future less and the present more, said lead researcher Bram Van Den Bergh of Katholieke Universiteit Leuven in Belgium. Viewing ads with women in bikinis had the same effect.
[…]
The bikini effect does vary in strength from person to person, Van Den Bergh said. While most men are vulnerable to subtle types of stimuli — like sexy ads and touching lingerie — others may need to see a woman nude before feeling impulsive. No matter, Van Den Bergh warned, “being exposed to a sexy girl may influence what stock you invest in or what candy bar you buy.”

OMG, they may start using this to influence purchasing patterns!