Writing up the evaporative cooling post on cold atom techniques, I used the standard analogy that people in the field use for describing the process: cooling an atomic vapor to BEC is like the cooling of a cup of coffee, where the hottest component particles manage to escape the system of interest, and what’s left… Continue reading Bose Condensation of Coffee?
Category: Physics
Tools of the Cold-Atom Trade: Evaporative Cooling
In our last installment of the cold-atom toolbox series, we talked about why you need magnetic traps to get to really ultra-cold samples– because the light scattering involved in laser cooling limits you to a temperature that’s too high for making Bose-Einstein condensation (BEC). This time out, we’ll talk about how you actually get to… Continue reading Tools of the Cold-Atom Trade: Evaporative Cooling
Tools of the Cold-Atom Trade: Magnetic Traps
We’re getting toward the end of the cold-atom technologies in my original list, but that doesn’t mean we’re scraping the bottom of the barrel. On the contrary, the remaining tools are among the most important for producing and studying truly ultra-cold atoms. Wait, isn’t what we’ve been talking about cold enough? There is, as always,… Continue reading Tools of the Cold-Atom Trade: Magnetic Traps
Tools of the Cold-Atom Trade: Magneto-Optical Traps
Today’s dip into the cold-atom toolbox is to explain the real workhorse of cold-atom physics, the magneto-optical trap. This is the technology that really makes laser cooling useful, by letting you collect massive numbers of atoms at very low temperatures and moderate density. Wait a minute, I thought we already had that, with optical molasses?… Continue reading Tools of the Cold-Atom Trade: Magneto-Optical Traps
Technology Is Science, Too
Via a retweeted link from Thony C. on Twitter, I ran across a blog post declaring science a “bourgeois pastime.” The argument, attributed to a book by Dierdre McCloskey is that rather than being at the root of economic progress, scientific advances are a by-product of economic advances. As society got more wealthy, it was… Continue reading Technology Is Science, Too
Tools of the Cold-Atom Trade: Optical Pumping and Sisyphus Cooling
This topic is an addition to the original list in the introductory post for the series, because I had thought I could deal with it in one of the other entries. Really, though, it deserves its own installment because of its important role in the history of laser cooling. Laser cooling would not be as… Continue reading Tools of the Cold-Atom Trade: Optical Pumping and Sisyphus Cooling
Why Do Small Science?
I spent an hour or so on Skype with a former student on Tuesday, talking about how physics is done in the CMS collaboration at the Large Hadron Collider. It’s always fascinating to get a look at a completely different way of doing science– as I said when I explained my questions, the longest author… Continue reading Why Do Small Science?
Tools of the Cold-Atom Trade: Optical Lattices
Last time in our trip through the cold-atom toolbox, we talked about light shifts, where the interaction with a laser changes the internal energy states of an atom in a way that can produce forces on those atoms. This allows the creation of “dipole traps” where cold atoms are held in the focus of a… Continue reading Tools of the Cold-Atom Trade: Optical Lattices
Physics Research Survey and Contest
One of my colleagues at Union is doing a physics education research project with a summer student, and is using an online survey to collect data. Obviously, the more people respond to the survey, the more scientific it becomes (subject to the limitations imposed by relying on self-selected Internet samples, of course), so I offered… Continue reading Physics Research Survey and Contest
Physics of the Bouncy-Bounce
SteelyPalooza came off very well, despite high disaster potential. We were, after all, inviting a dozen five-year-olds plus assorted siblings to our house, on a day when Kate and The Pip were out of commission due to coxsackie virus. Everything went smoothly, though: the kids loved the bouncy-bounce, SteelyKid’s playset and playhouse, and the six-person… Continue reading Physics of the Bouncy-Bounce