Archive for May 28th, 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.