I’m pretty sure I’ve used this topic before, but not with PollDaddy. And while I really ought to do a ResearchBlogging post today to make it a clean sweep for the week, I just don’t have the energy. So here’s a poll: what’s your favorite fundamental force? What’s your favorite fundamental force?online surveys Those of… Continue reading Dorky Poll: Favorite Force?
Tag: physics
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
High Excitement in Review: “Quantum information with Rydberg atoms”
I’m a big fan of review articles. For those not in academic science, “review article” means a long (tens of pages) paper collecting together the important results of some field of science, and presenting an overview of the whole thing. These vary somewhat in just how specific they are– some deal with both experiment and… Continue reading High Excitement in Review: “Quantum information with Rydberg atoms”
How Many Physics Professors Does It Take?
Johan Larson emails a suggestion for a post topic: How many profs would it take to offer a good, but not necessarily excellent, undergraduate physics degree? I can give you an empirical answer to this: Six. I say that because in the course of my undergraduate physics degree at Williams, I took classes from only… Continue reading How Many Physics Professors Does It Take?
The Science Mindset List
It’s nearly time for classes to resume, which means it’s time for a zillion stories about Beloit College’s annual Kids These Days List, listing off a bunch of things that this year’s entering college class, who were mostly born in 1992, have always taken for granted. A sample: 1. Few in the class know how… Continue reading The Science Mindset List
Why Antibunching Equals Photons
In my post about how we know photons exist, I make reference to the famous Kimble, Dagenais, and Mandel experiment showing “anti-bunching” of photons emitted from an excited atom. They observed that the probability of recording a second detector “click” a very short time after the first was small. This is conclusive evidence that photons… Continue reading Why Antibunching Equals Photons
Waves: Moving Without Going Anywhere
At the tail end of Tuesday’s post about wind and temperature, I asked a “vaguely related fun bonus question:” If the air molecules that surround us are moving at 500 m/s anyway, why isn’t the speed of sound more like 500 m/s than 300 m/s? This is another one that people are sometimes surprised by.… Continue reading Waves: Moving Without Going Anywhere
Quantum Optics from the Opposite Direction: QED Limits on Laser Intensities
Most of the time, when we talk about seeing quantum effects from light, we talk about extremely weak beams– looking at intensities where one photon more or less represents a significant change in the intensity of the light. Last week, though, Physics Buzz wrote up a paper that goes in the other direction: they suggest… Continue reading Quantum Optics from the Opposite Direction: QED Limits on Laser Intensities