Built on Facts

Archives for April, 2009

Normally I stay mostly on the physics beat, trying to mostly stay out of the controversy arena except occasionally when my lunatic reactionary politics crops up in something like my Social Security piece a while back. But all things considered I much prefer to a nice, collegial, uncontroversial discussion about eigenfunctions of the Dirichlet problem…

Rockets!

That Professor Goddard, with his ‘chair’ in Clark College and the countenancing of the Smithsonian Institution, does not know the relation of action to reaction, and of the need to have something better than a vacuum against which to react – to say that would be absurd. Of course he only seems to lack the…

Sunday Function

Yes, it’s Tuesday. Busy weekend, including a Relay for Life (you should find your local one and donate!). Today we’ll get back on schedule a bit and make this one a rather more utilitarian than usual Sunday Function, playing into the last step we’ll need in order to complete the Bose-Einstein condensation discussion. In the…

[This post is tremendously nerdy Star Wars fan ranting. There is no physics. You have been warned!] Let me get this straight: I tremendously enjoyed Star Wars: Episodes 1-3. I enjoyed them in all their badly-acted, incoherently characterized, effects-dependent glory. Every single one of them I walked into and out of the theater with a…

Bose-Einstein Condensates, pt. 3

“Everybody listen up!” shouts the high school PE coach, “I’m splitting you up into N teams of equal size. I’m going to make the selection of players randomly, so with any luck the teams will be of equal skill. The players with high skills all the way down the continuum to the players with low…

Bose-Einstein Condensates, pt. 2

Today we’re going to have to do some groundwork to set up for a step we’re going to need a post or two from now. It has to do with density in a slightly more abstract context than usual. Imagine you want to know how many people are living in a particular region. You can…

Bose-Einstein Condensates, pt. 1

It’s been a while since we’ve worked on some slightly more heavy-duty physics, so I’m going to spend the next couple of days going through the basics of the theory of Bose-Einstein condensation. Let me set the stage: Particles can be divided into two classes based on a quantum mechanical property called spin. Spin in…

Sunset Someday

Reader Timothy writes in with a question: It seems that the north pole would get more daylight during the summer solstice than the equator does during an equinox. During the summer solstice, the north pole would get the equivalent of (24hrs)sin(23.5 ° ) = 9.57 hours of sunlight from directly overhead (the zenith). During the…

Sunday Function

“So,” Herr Schrodinger says to us, “I’m looking for a function of x. It needs to be equal to the negative of its second derivative, up to a constant factor. When x is zero, the function itself should be zero. And when x equals L for some constant L greater than zero, the function also…

Testing 123

An emailer sends in a link to a comment on The White Coat Underground. It’s in the context of naturopathy, the idea that medical problems ought to be treated with natural means. Some of it’s a good idea – eating right, exercising, that sort of thing. Those sort of things aren’t going to cure much,…