Category: Physics

Dorky Poll: Document Preparation Software

The Pip is home with coxsackie virus today, and we’re having a big party for SteelyKid tomorrow (her fifth birthday is next week), so I’m too busy to do more cold-atom blogging today. So instead, we’ll consider one of the great linguistic conundra of modern physics: The document preparation system LaTeX is pronounced: This is… Continue reading Dorky Poll: Document Preparation Software

Tools of the Cold-Atom Trade: Light Shifts and Optical Dipole Traps

Schematic of a crossed-beam dipole trap from the Chen group at Chicago http://ultracold.uchicago.edu/csli_expwork

The last post in this series on the core technologies of cold-atom physics dealt with optical molasses, where you use the scattering of light to exert forces on atoms to make them very, very cold. It turns out, they end up even colder than the simple theory would lead you to expect, which is very… Continue reading Tools of the Cold-Atom Trade: Light Shifts and Optical Dipole Traps

Tools of the Cold-Atom Trade: Optical Molasses

The dormouse being stuffed into a teapot, from http://www.alice-in-wonderland.net/alice2a.html

`Once upon a time there were three little sisters,’ the Dormouse began in a great hurry; `and their names were Elsie, Lacie, and Tillie; and they lived at the bottom of a well–‘ `What did they live on?’ said Alice, who always took a great interest in questions of eating and drinking. `They lived on… Continue reading Tools of the Cold-Atom Trade: Optical Molasses

Tools of the Cold-Atom Trade: Light Scattering Forces and Slow Atomic Beams

Ryan McMartin '05 next to the Zeeman slower he built in my lab.

This series of posts is intended to explain the tools and tricks used to create and manipulate samples of ultra-cold atoms; thus, it’s appropriate to start with how we get those atoms in the first place. This will be a very quick background on the basic force used to make atoms cold, and then the… Continue reading Tools of the Cold-Atom Trade: Light Scattering Forces and Slow Atomic Beams

Tools of the Cold-Atom Trade: Introduction

Me and Emmy with some of the laser cooling apparatus in my lab.

I have a small collection of recent research papers that I’d like to write up open in various browser tabs and suchlike, but many of these would benefit from having some relatively clear and compact explanations of the underlying techniques. And while I can either dig up some old posts, or Google somebody else’s, it’s… Continue reading Tools of the Cold-Atom Trade: Introduction

Neil de Grasse Tyson Is John Harrison

Cover for The Hot Rock, from http://www.aintitcool.com/node/39275

Over at Galileo’s Pendulum, Matthew Francis expresses an opinion that’s sure to get him in trouble with the Inquisition and placed under house arrest: Carl Sagan’s Cosmos isn’t all that: However, even taking into account the differences in TV between 1980 and 2013, the show is very slow-paced at times. I’m not talking about the… Continue reading Neil de Grasse Tyson Is John Harrison

Driving a Simulated Pendulum

A simulated pendulum driven near resonance.

Some time back, I spent a bunch of time writing a VPython program that simulated the motion of a pendulum, which turned out to do some strange things. In the comments to that, there were two things worth mentioning: first and foremost, Arnoques at #5 spotted a small error in the code that fixes the… Continue reading Driving a Simulated Pendulum

Reflecting, Totally; or Why the Pool Looks Shiny from Underwater

Total internal reflection of a laser off a water surface.

The other day, I made a suggestion to one of my research students of an experiment to try. When I checked back a day later, she told me it hadn’t worked, and I immediately realized that what I had told her to do was very stupid. As penance, then, I’ll explain the underlying physics, which… Continue reading Reflecting, Totally; or Why the Pool Looks Shiny from Underwater

Baseball and Gender Bias: “Number of Women in Physics Departments: A Simulation Analysis “

Figure 3 from the AIP report discussed in the post.

I’ve spent a bunch of time recently blogging about baseball statistics, which you might be inclined to write off as some quirk of a sports-obsessed scientist. I was very amused, therefore, to see Inside Higher Ed and ZapperZ writing about a new AIP report on women in physics (PDF) that uses essentially the same sort… Continue reading Baseball and Gender Bias: “Number of Women in Physics Departments: A Simulation Analysis “

Naming Names in QED

Attendees at the Shelter Island workshop, from the APS: http://www.aps.org/units/fhp/newsletters/spring2011/schweber.cfm

I’m doing edits on the QED chapter of the book-in-progress today, and I’m struck again by the apparent randomness of the way credit gets attached to things. QED is a rich source of examples of this, but two in particular stand out, one experimental and the other theoretical. On the experimental side, it’s interesting to… Continue reading Naming Names in QED