Earlier this week, I talked about the technical requirements for taking a picture of an interference pattern from two independent lasers, and mentioned in passing that a 1967 experiment by Pfleegor and Mandel had already shown the interference effect. Their experiment was clever enough to deserve the ResearchBlogging Q&A treatment, though, so here we go:… Continue reading Interference of Independent Photon Beams: The Pfleegor-Mandel Experiment
Tag: experiment
Experiment vs. Theory: The Eternal Debate
Melissa at Confused at a Higher Level offers some thoughts on the relative status of experimental vs. theoretical science, spinning off a comprehensive discussion of the issues at Academic Jungle. I flagged this to comment on over the weekend, but then was too busy with SteelyKid and football to get to it. since I’m late… Continue reading Experiment vs. Theory: The Eternal Debate
The ABC’s of AMO Physics
Over at Confused at a Higher Level, Melissa offers an alphabetical list of essential supplies for a condensed matter experimentalist at a small college. This is a fun idea for back-to-school time, so I’ll steal it, and offer the following alphabetical list of essentials for Atomic, Molecular, and Optical physics at a small college, kind… Continue reading The ABC’s of AMO Physics
Without Experiment, There Is No Theory
A lot of people have been blogging and Twittering about this subway map of science, which puts various branches of science in the place of the lines on the London Underground map, showing connections between them. It’s a huge graphic, but a kind of cool image. I do, however, have a problem with it, which… Continue reading Without Experiment, There Is No Theory
Backyard Fluid Dynamics Revisited
Back in July, I did a post looking at how the fountain in our ornamental backyard pond shoots higher when the level of the pond drops. I set up a simple model of the process, which worked surprisingly well, but I said at the time that I really needed more data to say whether that… Continue reading Backyard Fluid Dynamics Revisited
Measuring Gravity: Ain’t Nothin’ but a G Thing
There’s a minor scandal in fundamental physics that doesn’t get talked about much, and it has to do with the very first fundamental force discovered, gravity. The scandal is the value of Newton’s gravitational constant G, which is the least well known of the fundamental constants, with a value of 6.674 28(67) x 10-11 m3… Continue reading Measuring Gravity: Ain’t Nothin’ but a G Thing
Melting Simulated Insulators
The Joerg Heber post that provided one of the two papers for yesterday’s Hanbury Brown Twiss-travaganza also included a write-up of a new paper in Nature on Mott insulators, which was also written up in Physics World. Most of the experimental details are quite similar to a paper by Markus Greiner’s group I wrote up… Continue reading Melting Simulated Insulators
Bunches and Antibunches of Atoms: Hanbury Brown and Twiss Effects in Ultracold Atoms
Two papers in one post this time out. One of these was brought to my attention by Joerg Heber, the other I was reminded of when checking some information for last week’s mathematical post on photons. They fit extremely well together though, and both relate to the photon correlation stuff I was talking about last… Continue reading Bunches and Antibunches of Atoms: Hanbury Brown and Twiss Effects in Ultracold Atoms
What Do You Need to Make Cold Atoms? Appendix: “No-Laser” Methods
Last week’s series of posts on the hardware needed for laser cooling and trapping experiments dealt specifically with laser-cooling type experiments. It’s possible, though, to make cold atoms without using laser cooling, using a number of techniques I described in two posts back in January. Those didn’t go into the hardware required, though, so what’s… Continue reading What Do You Need to Make Cold Atoms? Appendix: “No-Laser” Methods
What Do You Need to Make Cold Atoms? Part 3: Test and Measurement
The third category in our look at lab apparatus, after vacuum hardware and lasers and optics is the huge collection of electronic gear that we use to control the experiments. I’ll borrow the sales term “test and measurement” as a catch-all description, though this is really broader than what you’ll usually find in that category.… Continue reading What Do You Need to Make Cold Atoms? Part 3: Test and Measurement