Category: Experiment

Gravity Probe B Is in the Air

I no longer remember the context, but the Gravity Probe B experiment came up in discussion around the department last week, and nobody could really remember what the status of it was. It came up again during the “Physics: What We Don’t Understand” panel Saturday morning, where Geoff Landis was able to supply a few… Continue reading Gravity Probe B Is in the Air

Science and Sociology of Dark Matter

There’s a new paper from the PAMELA dark matter search out that’s written up in Physics, including a link to a free version of the PDF. This paper is considerably less dramatic than one that appeared last year, leading Physics World to suggest that they’re backing off the earlier claim. What’s the deal? Sean Carroll… Continue reading Science and Sociology of Dark Matter

Ultra-Cold Atoms and Neutrino Masses

Physics World‘s news aggregator had a story yesterday with the headline Chilly solution to neutrino mass problem, and the one-sentence teaser Ultracold atoms could be used to measure the mass of the neutrino. This creates a wonderful image of somehow turning a magneto-optical trap or a Bose-Einstein Condensate into a neutrino detector, which is a… Continue reading Ultra-Cold Atoms and Neutrino Masses

The Prestige for Ytterbium: Quantum Teleportation with Separated Atoms

My graduate alma mater made some news this week, with a new quantum teleportation experiment in which they “teleport” the state of one ytterbium ion to another ytterbium ion about a meter away. That may not sound like much, but it’s the first time anybody has done this with ions in two completely separate traps,… Continue reading The Prestige for Ytterbium: Quantum Teleportation with Separated Atoms

Subtracting Photons from Arbitrary Light Fields

There’s been a fair bit of press for the article Subtracting photons from arbitrary light fields: experimental test of coherent state invariance by single-photon annihilation, published last month in the New Journal of Physics, much of it in roughly the same form as the news story in Physics World (which is published by the same… Continue reading Subtracting Photons from Arbitrary Light Fields

Freezing Coherent Field Growth in a Cavity by the Quantum Zeno Effect

When I saw ZapperZ’s post about this paper (arxiv version, expensive journal version) from the group of Serge Haroche in Paris, I thought it might be something I would need to incorporate into Chapter 5 of the book-in-progress. Happily, it’s much too technical to require extensive re-writing. Having taken the time to read it, though,… Continue reading Freezing Coherent Field Growth in a Cavity by the Quantum Zeno Effect

Photoelectric Follies

I spent most of yesterday helping out with an on-campus workshop for high school teachers and students. Seven high school physics teachers and seventeen high school students spent the day doing a half-dozen experiments to measure various physical constants. I was in charge of having them measure Plack’s constant using the photoelectric effect. The actual… Continue reading Photoelectric Follies