Photons and Atoms Approaching Equilibrium

The latest snowstorm is wreaking some havoc on my plans for the day, which means I’m going to lift another question and answer from the Physics Stack Exchange, with some modification. This one is a question about thermal radiation: What are the quantum mechanisms behind the emission and absorption of thermal radiation at and below… Continue reading Photons and Atoms Approaching Equilibrium

Physics Announcements: New Forum, Undergraduate Research Session

I was at a meeting of the Committee on Informing the Public of the American Physical Society at the tail end of last week, so it seems appropriate to post a couple of APS-related announcements here on my return: 1) The APS has just created a Forum on Outreach and Engaging the Public. You may… Continue reading Physics Announcements: New Forum, Undergraduate Research Session

BEC: What Is It Good For?

Another response copied/adapted from the Physics Stack Exchange. The question was: What are the main practical applications that a Bose-Einstein condensate can have? Bose Einstein Condensation, for those who aren’t familiar with it, is a phenomenon where a gas of particles with the right spin properties cooled to a very low temeprature will suddenly “condense”… Continue reading BEC: What Is It Good For?

The Status of Simulations

Most of what would ordinarily be blogging time this morning got used up writing a response to a question at the Physics Stack Exchange. But having put all that effort in over there, I might as well put it to use here, too… The question comes from a person who did a poster on terminology… Continue reading The Status of Simulations

Poll: Top Physics Story of 2010?

It’s the last week of the (calendar) year, which means it’s a good time to recap the previous twelve months worth of scientific news. Typically, publications like Physics World will publish a list of top ten physics stories of 2010, but we’re all Web 2.0 these days, so it seems more appropriate to put this… Continue reading Poll: Top Physics Story of 2010?

How Does Light Travel Through Glass?

I’ve mentioned before that I’m answering the occasional question over at the Physics Stack Exchange site, a crowd-sourced physics Q&A. When I’m particularly pleased with a question and answer, I’ll be promoting them over here like, well, now. Yesterday, somebody posted this question: Consider a single photon (λ=532 nm) traveling through a plate of perfect… Continue reading How Does Light Travel Through Glass?

How Do You Trap an Ion, Anyway?

One of the many physics stories I haven’t had time to blog about recently is the demonstration of relativistic time effects using atomic clocks. I did mention a DAMOP talk about the experiment, but the actual paper was published in Science (and is freely available from the NIST Time and Frequency Division (PDF file), because… Continue reading How Do You Trap an Ion, Anyway?

Physics Is All About Analogies

Regular commenter onymous left a comment to my review of Warped Passages that struck me as a little odd: The extended analogy between the renormalization group and a bureaucracy convinced me that she was trying way too hard to make sophisticated concepts comprehensible. Also, I’m not really sure that analogies are the best way to… Continue reading Physics Is All About Analogies