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
Tag: science
Bad Universe, No Biscuit
Sunday was a really long day around Chateau Steelypips, and I couldn’t see staying awake to watch the premiere of Phil Plait’s Bad Universe on the Discovery Channel, so I’m way late in writing about it. I DVRed it, though, and watched it last night. The theme of the premiere/ pilot was killer rocks from… Continue reading Bad Universe, No Biscuit
Indirect Excitation Control: Ultrafast Quantum Gates for Single Atomic Qubits
Last week, John Baez posted a report on a seminar by Dzimitry Matsukevich on ion trap quantum information issues. In the middle of this, he writes: Once our molecular ions are cold, how can we get them into specific desired states? Use a mode locked pulsed laser to drive stimulated Raman transitions. Huh? As far… Continue reading Indirect Excitation Control: Ultrafast Quantum Gates for Single Atomic Qubits
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