Archive for May, 2009

CSI Utah

Mysterious disappearance of explorer Everett Ruess solved after 75 years

The mysterious disappearance of Everett Ruess, a 20-year-old artist, writer and footloose explorer who wandered the Southwest in the early 1930s on a burro and who has become a folk hero to many, has been solved with the help of University of Colorado at Boulder researchers and the National Geographic Society. The short, compelling life of Ruess, who went missing in 1934 after leaving the town of Escalante, Utah, has been the subject of much speculation.

Not-so-Great Expectations

Gendered expectations in teaching

[T]he expectations of how a male versus female instructor will behave are actually quite different. One of the papers I read discussed the fact that they interviewed students after they filled out evaluations (where a male versus a female teacher were rated and came out the same, quantitatively). It turns out that while the teachers were rated the same, the students have obvious differences in expectations. It came out that female instructors were available outside of class for more time than male instructors, but that they were still viewed as not being sufficiently accessible outside of class. In other words, students expected that female instructors should be willing to put in more time outside of class to help students in order to rate as well as male instructors who put in less time. If you think about the implications, it basically means that women will often have to do more work to get the same ratings.

The Color of Math

sciencegeekgirl: Physics Toys Tuesday: Colored shadows

Color subtraction is what happens when you mix together pigments. Red pigment absorbs all light but red (which is reflected to your eye). Blue pigment absorbs all light but blue. So mix red and blue and you’ve subtracted all colors, getting black.

Light’s weird, though. You mix together all colors of light and you get white. The primary colors of light are red, green, and blue. You have receptors in your eyes for each of those colors. If your eye senses both red and green light at the same place, your brain says “cyan” (sort of blue-green).

Oh, Sure. Take All of the Fun Out of It.

A Unified Quantum Theory of the Sexual Interaction

In the simplest theories of the sexual interaction, the eigenstates of the Hamiltonian describing all allowed forms of two-body coupling are identified with the conventional gender states, “Male” and “Female” denoted |M> and |F> in the Dirac bra-ket notation; note that the bra is superfluous in this context so, as usual, we dispense with it at the outset. Interactions between |M> and |F> states are assumed to be attractive while those between |M> and |M> or |F> and |F> are supposed either to be repulsive or, in some theories, entirely forbidden.

The treatment, however, is incomplete. There is no mention of the difficulty of describing an interaction in the dressed-state picture. Nor any analysis showing that M-F coupling with aligned spins may, with some probability, be equivalent to applying the creation operator (clearly, these are bosons), while in interactions with spins anti-aligned, this does not happen; both interactions usually occur with both particles in an excited state.

wavefunction

Evidence of Things Not Seen

Until you do a CAT scan.

NYT: Autopsies of War Dead Reveal Ways to Save Others

Col. Howard T. Harcke, a 71-year-old Marine Corps radiologist who delayed retirement to read CT scans at Dover, noticed something peculiar in late 2005. The emergency treatment for a collapsed lung involves inserting a needle and tube into the chest cavity to relieve pressure and allow the lung to reinflate. But in one case, Colonel Harcke could see from a scan that the tube was too short to reach the chest cavity. Then he saw another case, and another, and half a dozen more.

In an interview, Colonel Harcke said it was impossible to tell whether anyone had died because the tubes were too short; all had other severe injuries. But a collapsed lung can be life-threatening, so proper treatment is essential.

Colonel Harcke pulled 100 scans from the archives and used them to calculate the average thickness of the chest wall in American troops; he found that the standard tubing, five centimeters long, was too short for 50 percent of the troops. If the tubing was lengthened to eight centimeters, it would be long enough for 99 percent.

“Soldiers are bigger and stronger now,” Colonel Harcke said.

The findings were presented to the Army Surgeon General, who in August 2006 ordered that the kits given to combat medics be changed to include only the longer tubing.

This reminds me of a story, possibly apocryphal, of a study done in WWII. The army wanted more armor on bombers to protect them, but needed to be selective about where it was placed, lest the speed and/or range suffer too much. And they didn’t really want to take planes in production to test them, since they were all needed in battle. So some people analyzed the damage pattern of planes that returned from missions. They assumed that anti-aircraft bursts were basically random, so the pattern of damage from returning aircraft indicated non-critical harm, and were areas that didn’t need reinforcing — it was the gaps in the pattern which indicated the fatal hits. and that was where additional armor would do the most good.

Escape from Flatland

3-D Sheep Animal Crackers

Who’s That, Jack Spratt?

In the recent foray into the physics of Goldilocks and the Three Bears, there was a comment on Chad’s post which mentioned Jasper Fforde’s The Fourth Bear. I had read the first book in the series, so I picked this one up a few weeks ago, and since this is the Jell-0 of reading material — always room for it — I finished it while atomic physics was still leaking out of my ears.

It’s good. Detective Inspector Jack Spratt is in charge of the Nursery Crimes Division, responsible for investigating any crimes involving anthropomorphized animals or persons of dubious reality from works of fiction, especially nursery rhymes. Vaguely reminiscent of Douglas Adams in terms of zanyness, but it all makes some weird sort of sense. As promised, the thermodynamics of the three bowls of porridge (a quasi-controlled substance, permissible only in rationed amounts) gives Jack a major clue to solve the intertwined mysteries in the book. There is another physics nit, though. It’s a spoiler, though, so stop reading if you plan on reading the book. Continued below the fold.
Read more »

What He Said

PhD Comics: The science news cycle

The Inside Job

Scott Adams (fellow Hartwick alum) continually tells people, “No, I don’t work at your company,” because the problems he lampoons are so widespread.

Allyson points out a problem that is less so, that of purchasing within government regulations, in the shoe bomber theory of purchasing regulations. So in this case she does work at my company, in a sense. I feel her pain. And this is exactly right.

In 2001, a jackhole named Richard Reid got on a plane and attempted to make it go ‘splody by lighting a bomb in his shoes.

Now we all have to suffer the indignity of standing barefoot in line at the airport while the security goons X-ray my Hello Kitty flip flops. An appropriate punishment for Mr. Reid would be to chain him to the metal detector at various airports and then we could all smack him in the chops with our shoes before boarding the plane.

Likewise, somewhere out there, some jackass probably used his government p-card to buy a hooker, forty-eight pounds of veal, a case of absinthe, and a weed whacker for a groovy night of debauchery at a conference in Madrid.

Then some bored reporter showed up to blow the lid off this travesty as if s/he had discovered a Woodward and Bernsteinesque plot, it all ended up on the evening news, and suddenly I need to get sixty-eight approvals from the head of NASA all the way to my mom (hi mom!) to order a box of Kim Wipes. I hate waiting for stuff.

Most of the “solutions” with which we purchase card holders are burdened are the result of poor oversight. The probably-not-so-farfetched scenario Allyson describes would normally be caught in the routine audit when the jackass submitted his statement, and it was reviewed by the next person up the chain — no need for any additional regulations at all, if the reviewing official was doing the job properly. But somehow lapdances and sushi are purchased and not discovered until much later, and the solution is to add more rules to the mix. The problem is that it doesn’t really do any good — incompetent review hasn’t changed, and if someone is hell-bent on defrauding the government, they (by definition) don’t follow the rules, so a new layer of them won’t matter. Especially if the new rule has huge loopholes in it, as it usually does.

So I heartily endorse the solution

Whenever a new control is put in place that causes me to wait additional time for an approval, I believe that the new approval process should be named after the jerk who caused the problem to begin with.

Those Who Can, Do.

The Breakdown: Defying Death at the Gym

Neat little gymnastics demonstration that you will never catch me attempting, because it looks like an engraved invitation to a serious injury. The physics is much less strenuous, being an exercise in conservation of linear and angular momentum. If you read through the comments you’ll find someone who insists the explanation is wrong, because kinetic energy isn’t conserved in inelastic collisions. But kinetic energy isn’t mentioned in the explanation, so file that under “W” for “WTF?” The same poster returns to dig his hole even deeper by insisting that momentum isn’t conserved, either. It’s scary if they are indeed a teacher of statics and dynamics.

Fuelish

World’s first battery fuelled by air

I don’t think so. No more than your car is fueled by air when you have combustion. The difference is between carrying around oxygen in the cell, and drawing some oxygen in from the air in order to complete the reaction and release energy.

If you go to the group’s website, they explain the basic process:

On discharge, Li+ from the electrolyte and e- from the external circuit combine with O2 from the air, the process is reversible.

The big win is not carrying around Oxygen, which is more than twice as massive as Lithium. There’s also carbon and a catalyst involved, but of course a catalyst gets reused, and so you don’t need a stoichiometric fraction of that present. In the article at Green Car Congress it’s mentioned that the catalyst is Mn.

The Guardian article also claims

And as the cycle of air helps re-charge the battery as it is used, it has a greater storage capacity than other similar-sized cells and can emit power up to 10 times longer.

I see nothing supporting the claim that any kind of recharging is going on.

Every Dog Bowl Has its Day

I’m way behind in my blog reading. Here’s a little optics something from ZapperZ:
Can a dog bowl start a fire? Test shows idea does hold water

A Bellevue Fire Department investigator said earlier this week that he suspects a house fire started when a partially filled glass bowl, resting in a wire stand on the home’s deck, concentrated the sun’s rays like a magnifying glass.

Reminiscent of the snow globes that were recalled for their similar qualities of refraction.

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