Month: August 2013

Reading Begins With Siblings

SteelyKid and The Pip checking out the merchandise at the bookstore.

The “featured image” above shows SteelyKid and The Pip checking out a couple of books at The Open Door during our weekly trip to the Schenectady Greenmarket. As cute as this is, though, the image can’t do justice to the full scenario. We were in the toy section looking for a birthday present for SteelyKid’s… Continue reading Reading Begins With Siblings

Santa Claus Doesn’t Live Here Any More

The shy and retiring SteelyKid.

SteelyKid: I din’t eat all my lunch today, because I didn’t have time. Daddy: Uh-huh. SK: It’s true! I’m not even lying. D: Oh, I believe you didn’t eat all your lunch, don’t worry about that. SK: Ask Santa Claus if you think I’m lying. D: Santa Claus? SK: Yeah. Santa Claus actually can’t see… Continue reading Santa Claus Doesn’t Live Here Any More

Tools of the Cold-Atom Trade: Atom Detection and Imaging

Sample images with and without atoms, and the subtracted image used to study BEC. From an old talk.

This is probably the last trip into the cold atom toolbox, unless I think of something else while I’m writing it. But don’t make the mistake of assuming it’s an afterthought– far from it. In some ways, today’s topic is the most important, because it covers the ways that we study the atoms once we… Continue reading Tools of the Cold-Atom Trade: Atom Detection and Imaging

Bose Condensation of Coffee?

Coffee and a notebook, from a fun Physics Stack Exchange discussion.

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?

Tools of the Cold-Atom Trade: Evaporative Cooling

The signature image of a cloud of rubidium atoms crossing the BEC transition, from the Nobel Prize site.

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

A Pox on Both Your Cultures

A lot has been written about Steven Pinker’s article about “scientism,” most of it mocking his grandiose overreach in passages like this: These thinkers—Descartes, Spinoza, Hobbes, Locke, Hume, Rousseau, Leibniz, Kant, Smith—are all the more remarkable for having crafted their ideas in the absence of formal theory and empirical data. The mathematical theories of information,… Continue reading A Pox on Both Your Cultures

Tools of the Cold-Atom Trade: Magnetic Traps

Eric Cornell and Carl Wieman next to the original BEC apparatus, from http://www2.physics.utu.fi/projects/kurssit/FFYS4497/bec/H1-CarlWieman-EricCornell.gif

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

Kris Helmerson of NIST looking into the vacuum chamber at a sodium MOT.

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

Japanese swords from the 13th and 17th centuries, from Wikimedia

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

White People Only Have 2.8 Friends

Screen shot of the Reutrers poll data, from the data explorer linked in the text.

There was some buzz Thursday about a poll showing that 40% of white people don’t have any friends of a different race. Ipsos/Reuters include a spiffy “data explorer” where you can make graphs like the one above. It does not appear to provide an easy way to get at the actual wording of the question,… Continue reading White People Only Have 2.8 Friends