Theory

Category archives for Theory

We cleared a bunch of space in our deep storage area over the summer, and one of the things we found was a box full of old student theses from the 1950′s and 1960′s. The library already had copies of them, but I thought it was sort of cool to have a look into the…

I’m putting together slides for a TED audition talk in a couple of weeks, about how the history of quantum mechanics is like a crossword puzzle. This involves talking about black-body radiation, which is the problem that kicked off QM– to explain the spectrum of light emitted by hot objects, Max Planck had to resort…

Trapping Neutrinos?

One of the chapters of the book-in-progress talks about neutrino detection, drawing heavily on a forthcoming book I was sent for blurb/review purposes (about which more later). One of the little quirks of the book is that the author regularly referred to physicists trying to “trap” neutrinos. It took me a while to realize that…

Fun With Simulated Scattering

Two chapters of the book-in-progress will be devoted to the development of the modern understanding of the atom. One of these is about the Bohr model, which turned 100 this year, but Bohr’s model would not have been possible without an earlier experiment. The actual experiment was done by Ernest Marsden and Hans Geiger, but…

Spooky Action at What Distance?

When I wrote up the giant interferometer experiment at Stanford, I noted that they’ve managed to create a situation where the wavefunction of the atoms passing through their interferometer contains two peaks separated by almost a centimeter and a half. This isn’t two clouds of atoms each definitely in a particular position, mind, this is…

I’m writing a bit for the book-in-progress about neutrinos– prompted by a forthcoming book by Ray Jaywardhana that I was sent for review– and in looking for material, I ran across a great quote from Arthur Stanley Eddington, the British astronomer and science popularizer best known for his eclipse observations that confirmed the bending of…

Driving a Simulated Pendulum

Some time back, I spent a bunch of time writing a VPython program that simulated the motion of a pendulum, which turned out to do some strange things. In the comments to that, there were two things worth mentioning: first and foremost, Arnoques at #5 spotted a small error in the code that fixes the…

Naming Names in QED

I’m doing edits on the QED chapter of the book-in-progress today, and I’m struck again by the apparent randomness of the way credit gets attached to things. QED is a rich source of examples of this, but two in particular stand out, one experimental and the other theoretical. On the experimental side, it’s interesting to…

The Making of a Sign Error

One thing I left out of the making-of story about the squeezed state BEC paper last week happened a while after publication– a few months to a year later. I don’t quite recall when it was– I vaguely think I was still at Yale, but I could be misremembering. It’s kind of amusing, in an…

I spend a lot of time promoting Rhett Allain’s Dot Physics blog, enough that some people probably wonder if I get a cut of his royalties (I don’t). I’m going to take issue with his latest, though, because he’s decided to revive his quixotic campaign against photons, or at least teaching about photons early in…