Unlike some pursuits, in science new information sometimes means having to revise your conclusion. Just after snarking about how unscientific congress is, I read that Bill Foster, another physicist, has been elected to fill Dennis Hastert’s seat.
So the raising operator has been applied by the good people of the 14th district in Illinois, at least until November, when the measurement gets redone.
Why Can’t a Woman Be More Like a Man?
An interesting article on the gender-representation issue in the sciences. Many assume it’s all sexism, but whenever somebody checks to see if that’s really the case, two things seem to happen: they come to the conclusion, “Not so much,” and they are often attacked for raising the question. Congress has gotten into the act, with a push for a “Title IX for Science.” I’m all for removing barriers that might prevent women from pursuing a career in a science discipline, or shunt them into some other discipline against their desire, but if you don’t ask the question of how we know it’s sexism, such a path is, well, unscientific. (of course, that’s not surprising, since politics and political-correctness is involved). But the Title IX analogy fails, because science doesn’t have a men’s league and women’s league.
There is another essential difference between sports and science: in science, men and women play on the same teams. Very few women can compete on equal terms with men in lacrosse, wrestling, or basketball; by contrast, there are many brilliant women in the top ranks of every field of science and technology, and no one doubts their ability to compete on equal terms.
I think one of the problems in this issue is that some people are taking “men and women are equal” and subtly (or not-so-subtly) taking that to mean “men and women are identical.” And assuming that because the former is true that the latter must be as well.
via Twisted One 151
There’s also a new book, reviewed at the NY TImes, related to this topic. The Sexual Paradox by Susan Pinker.
Pinker parks herself firmly among “difference” feminists. Women’s brains aren’t inferior, she argues, but they vary considerably from men’s, and this is the primary explanation for the workplace gender divide
Over at Physics and Physicists, ZapperZ has a short post on an interference experiment that looks like a useful apparatus to demonstrate some of the quirkiness of QM. It shows both single-photon interference and, since it’s a Mach-Zehnder interferometer, it’s also easy to show the “which-path” effect that washes away the fringes.
While poking around looking into the DST-doesn’t-save-energy story, looking for something that didn’t just link back to the WSJ story, I ran across this: a new lamp being hyped by some sites with a “green” tint, called Gravia. (a second story is here at treehugger)
The lamp took second place in the Greener Gadgets Design Competition. It’s described as being gravity-powered, which is wrong. It’s human-powered — you lift 50 lbs, and the weight falling back down supplies energy to some LEDs, and is supposed to supply 600-800 lumens, or the equivalent of about a 40-W light bulb, for four hours. Something about this immediately struck me as being wrong. You aren’t going to power the equivalent of a 40-W light bulb with that, not even with really efficient LEDs. 50 lbs, lifted a bit over a meter, will require 250 Joules of work. Over 4 hours, that’s 17 milliWatts of output. That didn’t add up — even the best LEDs are only 5 to 10 times more efficient than incandescent bulbs. There’s no way this can work.
And sure enough, that’s what I found
My memory was just jogged, bringing this to the fore. A series of cool analemma pictures taken in Greece, showing ruins in the foreground, with the additional feature of some being multiple exposures on a single frame of film.
The analemma — which you can often see on a globe — describes the variation in the position of the sun over the course of the year. Besides the pretty obvious vertical motion you get from the axial tilt of the earth, there is also the effect from the noncircular nature of the earth’s orbit. This causes the earth’s speed to change over the course of the year, so we do not sweep out exactly the same angle from day to day, if you were to assume that noon is when the sun reaches some position in the sky (like straight overhead, or on the vertical line that includes that point). In other words, the time you would read on a sundial will not agree with the time kept by a very good clock. The variation over the course of the year is on order of ± 15 minutes, or almost 4º of arc in each direction. The math that describes this is known as the equation of time.
For a peek at a few more illusions, of the “interchanging 2-D and 3-D” variety, as well as some history & physics behind it all, head on over to Skulls in the Stars.
One of the neat things about traffic is how it can be analyzed in terms of some physics parameters. You get density waves that can propagate, and end up getting slowdowns that can persist long after the original cause is gone. Or, as this video shows, there doesn’t have to be a real cause, like an accident or scantily-clad jogger distracting the drivers. Just statistical fluctuation can be enough to send a shockwave through the traffic.
There’s a short article as well
(via Cognitive Daily)
UPDATE: more on this at Backreaction. Actual analysis.
The plot shows nicely how the perturbation – the zone of zero velocity (aka the jam) – travels at constant speed in the direction opposite to the traffic flow.
FemaleScienceProfessor discusses the pros and cons of talk vs. poster, confounded by the politics of being involved in the conference. Physics conferences in particular have a certain breakdown that’s mentioned over at Uncertain Principles, that being invited talks, contributed talks and posters. It was my impression that posters weren’t nearly as big a thing in the particle physics community vs the AMO community, during my postdoc at an accelerator lab some years back — I was gearing up for an atomic physics conference, to discuss the double-MOT system we had, and how we transferred the atoms, and the particle men acted like they weren’t familiar with the concept of a poster session.
One aspect of talk vs. poster is how important is it to be seen, as opposed to how important it is to get experimental details out (as much as you can do that in 10 minutes or so). In that case it was a description of an apparatus and not any real experimental results, so a poster made sense. When we had some experimental results, I gave a talk, and that gave the attendees a chance to see me and associate my face with that experiment — several or many dozen, as opposed to a smaller number that might have dropped by a poster. (Of course, a smaller number isn’t so bad when it includes a Nobel prize-winner or winner-to-be).
What I remember about that particular talk is that the program listed the talks as being 15 minutes long: 12 minutes of talking, with 3 more for questions. During the announcements preceding the plenary session, we were informed that that was a typo in the program, and the talks were actually just 12 minutes total: 10 for presentation and 2 for questions. The poor people giving talks that day had no chance to revise things and cut down their presentations, and everything ran late. I at least had that evening to make adjustments and drop a slide to bring my talk in in the allotted time.
Of Two Minds discussing Could Superman’s X-Ray Vision Really Exist?