Friday, November 30, 2012

Effect of Good Teachers

This NYTimes article alerts us to work done on the efficacy of good teachers. The conclusion: good teachers are good. The article mentions "poor performing" teachers and the some comments debate about what do do about them, now that there is proof that good teachers are good.

A couple of thoughts. First, the effect is quite modest for an individual student, an increase of about $4600 in LIFETIME income. To me, the modesty of the gain underscores the notion that one teacher is just one variable in a sea of about 1000 variables, including socioeconomic status, family situation, race, peers, administrators, etc. But cumulatively, over a teacher's career, this results in about 2.5 million in increased earnings.

Maybe "good" teachers should get this figure as bonus on retirement. Not kidding, but wouldn't it be peachy?

Of course the question remains, how to weed out the bad apples. This seems the exact opposite tack to take. Our best and brightest (and medium best and medium brightest) are choosing "professional" careers. Teaching, in this country, has not garnered the respect of a profession, because it is historically low-paying. [Actually, most jobs once (or currently) dominated by women are underpaid, and that's another article I'll get to some day.]

Can we please just raise teachers' salaries and attract the good ones, rather than focusing on weeding out the bad ones?

Film Consulting

I'm sure they do good work, can we please have more of this stuff?


http://www.hollywoodmath.com/index.htm


How hard would it be for almost every film to have a bona-fide science consultant? Even "low-budget" films have a pretty high sticker price. Not that they should be underpaid, but I'm sure a fair number of scientists would be willing to help out for far less than their market value as a consultant (a different sort of mini-sabbatical, for sure!). Bottom line, having a science consultant shouldn't affect the budget too much - why wouldn't you?

And for your extremely high budget pictures, don't skimp and just get one consultant. You don't skip on cameramen or costume designers. Far too many good movies, even movies with a heaping serving of science, are riddled with errors.


Protein Folding

I'm currently in the process of going through a monstrous stack of periodicals I've accumulated, including the magazine Physics Today, which comes with my APS membership.

This article by Ashley Smart is simply a research summary on experiments on proteins.

But Smart evoked a lot of thoughts about proteins. We need them to be folded correctly to work, but how are they folded? How is this the minimum energy state.

Smart's description of various denatured (unfolded) proteins reminded me a lot of the language used in the glass/jamming community. A fried egg consists of proteins denatured by heat. A similar transition happens for
"glassy" systems: raise the temperature and the material will flow.

Mechanical stress can cause also cause the protein in egg white to denature, resulting in a foamy, stiff, meringue. In jammed systems, like mayonnaise, mechanical stress (i.e. using a butter knife) causes the material to unjam (i.e. deform and spread on the sandwich).

The third variable discussed in the jamming community is volume fraction, which I won't delve into here. The third variable for the egg example is acidity, mixing egg whites with lime juice will also cause the proteins to denature. Completely different, can't win 'em all.

What also drew me into this simple piece was the description of the experiments. (Smart does a commendable job of trying to explain the math in words.) There are two processes that contribute to the overall signal the researchers measure, only one of which relates to protein folding. But if you change the temperature, each process responds on a vastly different timescale.Taking measurements at the right frequency and using a trick of derivatives, they can isolate the process of interest. An experiment like this would be a great lab in a biophysics class.

Friday, November 2, 2012

Hurricane Science

A good article about physics and hurricanes! I am also reminded of my article which emphasized the effects of storm surge rather than category (though the editors wanted to emphasize the forecast more that anything else). And indeed, surge was the issue with Sandy.