Category: Experiment

What Do You Need to Make Cold Atoms? Part 2: Lasers and Optics

Following on yesterday’s discussion of the vacuum hardware needed for cooling atoms, let’s talk about the other main component of the apparatus: the optical system. The primary technique used for making cold atoms is laser cooling, and I’m sure it will come as no surprise that this requires lasers, and where there are lasers, there… Continue reading What Do You Need to Make Cold Atoms? Part 2: Lasers and Optics

What Do You Need to Make Cold Atoms? Part 1: Vacuum Hardware

Over in the reader request thread, Richard asks for experimental details: I’d be interested in (probably a series) of posts on how people practically actually do cold atoms experiments because I don’t really know. I needed to take some new publicity photos of the lab anyway, so this is a good excuse to bust out… Continue reading What Do You Need to Make Cold Atoms? Part 1: Vacuum Hardware

Cold Atoms and Cooper Pairs

So, last week, I talked about how superconductors work, and I have in the past talked about the idea of making cold atoms look like electrons. And obvious question, then, whould be: Do cold atoms systems allow us to learn anything about superconductivity? The answer here is, unfortunately, “Yes and no.” That’s pretty weaselly, dude.… Continue reading Cold Atoms and Cooper Pairs

What’s a Photon, and How Do We Know they Exist?

A reader emailed me with a few questions regarding How to Teach Physics to Your Dog, one of which is too good not to turn into a blog post: What is a photon from an experimental perspective?… Could you perhaps provide me with a reference that discusses some experiments and these definitional issues? The short… Continue reading What’s a Photon, and How Do We Know they Exist?

Baez on Leggett on High-Temperature Superconductors

I had the tab open and everything, and still somehow forgot to include a link to John Baez’s blog post reporting on a talk by Tony Leggett which directly addresses some of the questions asked about yesterday’s superconductivity post. It’s about a talk called “Cuprate superconductivity: the current state of play” (“state of play” apparently… Continue reading Baez on Leggett on High-Temperature Superconductors

How Do Superconductors Work?

In the reader request thread, Brad asks about superconductors: Why is a room temperature superconductor so hard? Why do things have to be cold for there to be no resistance (I can guess, but my knowledge of super conductors consists of the words “Cooper pairs” which does not get me very far.) Since next year… Continue reading How Do Superconductors Work?

Murphy Violation in Science

Over at Unqualified Offerings, Thoreau proposes an an experimental test of Murphy’s Law using the lottery. While amusing, it’s ultimately flawed– Murphy’s Law is something of the form: Anything that can go wrong, will. Accordingly, it can only properly be applied to situations in which there is a reasonable expectation of success, unless something goes… Continue reading Murphy Violation in Science

When Should You Open Your Car Windows? An Experiment

Back at the start of the summer, I asked a question about automotive thermodynamics: On a hot day, is it better to open your car windows a crack when making a short stop, or leave them closed? For a long term– say, leaving your car parked outside all day– I hope everyone will agree that… Continue reading When Should You Open Your Car Windows? An Experiment

Measuring Temperature by Counting Atoms: “Suppressed Fluctuations in Fermi Gases”

When one of the most recent issues of Physical Review Letters hit my inbox, I immediately flagged these two papers as something to write up for ResearchBlogging. This I looked at the accompanying viewpoint in Physics, and discovered that Chris Westbrook already did most of the work for me. And, as a bonus, you can… Continue reading Measuring Temperature by Counting Atoms: “Suppressed Fluctuations in Fermi Gases”