September 5, 2013
While I'm quoting other people saying smart things, Timothy Burke has another great post on the failures of economic models of higher education
There is a lot of information that you could acquire about courses or about colleges that you could reasonably use to assemble a decision matrix. What size…
September 5, 2013
The stupid Steven Pinker business from a few weeks ago turned out to do one good thing after all. It led to this post at Making Science Public, which quoted some books by Jacob Bronowski that sounded relevant to my interests. And, indeed, on checking The Common Sense of Science out of the college…
September 4, 2013
Two chapters of the book-in-progress will be devoted to the development of the modern understanding of the atom. One of these is about the Bohr model, which turned 100 this year, but Bohr's model would not have been possible without an earlier experiment. The actual experiment was done by Ernest…
September 3, 2013
I started out blogging about books, way back in 2001, but somewhat ironically, I rarely post anything about books any more. My free time has been whittled down to the point where book blogging is time taken away from other stuff, and it's never been that popular here. I post reviews of science…
September 3, 2013
Element: Cesium (Cs)
Atomic Number: 55
Mass: One stable isotope, mass 133 amu.
Laser cooling wavelength: 854nm, but see below.
Doppler cooling limit: 125 μK.
Chemical classification: Yet another alkali metal, column I of the periodic table.
This one isn't greyish, though! It's kind of gold color.…
September 2, 2013
It's Labor Day in the US, and due to a weird quirk of scheduling, for once I didn't have to spend it at work. This is also the traditional end of the summer season, so SteelyKid and I went over to the JCC pool for one last dip and a final ice cream cone from the snack bar:
Last ice cream of pool…
August 31, 2013
We won a family pass to the Empire State Aerosciences Museum just across the river in Glenville, and since soccer was canceled for the holiday weekend, I took the kids over there this morning. They had a couple of their collection of decommissioned military aircraft open, including the Huey…
August 30, 2013
It's been a banner week for blogging advice, between John Scalzi's thoughts on comments and Bee's advice on whether to write a science blog. Both of them are worth a read, and I don't have a great deal to add, but writing the stuff I'm supposed to be writing this morning is like pulling my own…
August 29, 2013
Element: Chromium (Cr)
Atomic Number: 24
Mass: Four "stable" isotopes between 50 and 54 amu. Chromium-50 is technically radioactive, with a half-life considerably longer than the age of the universe, so...
Laser cooling wavelength: 425nm, but see below.
Doppler cooling limit: 120 μK.
Chemical…
August 28, 2013
I've been revising a chapter on collaboration in science for the book-in-progress, making an analogy to team sports. And it occurred to me as I was trying to find a way to procrastinate, that while science is a highly collaborative endeavor, most of the popular stories that get told about science…
August 28, 2013
Element: Lithium (Li)
Atomic Number: 3
Mass: Two stable isotopes, masses 6 and 7 amu
Laser cooling wavelength: 671 nm
Doppler cooling limit: 140 μK.
Chemical classification: Alkali metal, column I in the periodic table. Yet another greyish metal. We're almost done with alkalis, I promise. Less…
August 27, 2013
Element: Francium (Fr)
Atomic Number: 87
Mass: Numerous isotopes ranging in mass from 199 amu to 232 amu, none of them stable. The only ones laser cooled are the five between 208 amu and 212 amu, plus the one at 221 amu.
Laser cooling wavelength: 718 nm
Doppler cooling limit: 182 μK.
Chemical…
August 26, 2013
The list of editions of my books in character sets I can't read just got bigger: I got author copies of the Thai edition of How to Teach Physics to Your Dog. The cover is the "featured image" above (and I'll copy it below for those on RSS), and I love the goofy tongue on the cartoon German Shepherd…
August 26, 2013
In one of those Information Supercollider moments, two very different articles crossed in my social media feeds, and suddenly seemed to be related. The first was this New York Post piece by a college essay consultant:
Finally, after 15 or so years of parents managing every variable, there comes the…
August 26, 2013
Element: Strontium (Sr)
Atomic Number: 38
Mass: Four stable isotopes, ranging from 84 to 88 amu
Laser cooling wavelength: Two different transitions are used in the laser cooling of strontium: a blue line at 461 nm that's an ordinary sort of transition, and an exceptionally narrow "intercombination…
August 25, 2013
Early last year, we began marking SteelyKid's height off on a door frame in the library. She occasionally demands a re-measurement, and Saturday was one of those days. Which made me notice that we now have a substantial number of heights recorded, and you know what that means: it's time for a graph…
August 23, 2013
Adam Frank has an op-ed at the New York Times that tells a very familiar story: science is on the decline, and we're living in an "Age of Denial".
IN 1982, polls showed that 44 percent of Americans believed God had created human beings in their present form. Thirty years later, the fraction of the…
August 22, 2013
When I wrote up the giant interferometer experiment at Stanford, I noted that they've managed to create a situation where the wavefunction of the atoms passing through their interferometer contains two peaks separated by almost a centimeter and a half. This isn't two clouds of atoms each definitely…
August 22, 2013
Element: Xenon (Xe)
Atomic Number: 54
Mass: nine "stable" isotopes, masses from 124 to 136 amu. Xenon-136 is technically radioactive, but with a half-life of a hundred billion billion years, so, you know, it's pretty much stable.
Laser cooling wavelength: 882 nm
Doppler cooling limit: 120 μK…
August 21, 2013
After a couple of very productive days where I closed my Twitter tab because it was too freakin' annoying to read, I checked in briefly Wednesday morning, and found Rhett Allain and Frank Noschese discussing this Veritasium bullet-in-block experiment:
Tom at Swans On Tea offers some analysis, and…
August 21, 2013
Element: Helium (He)
Atomic Number: 2
Mass: two stable isotopes, 3 and 4 amu.
Laser cooling wavelength: 1083 nm
Doppler cooling limit: 38 μK
(It should be noted, though, that despite the low temperature, laser-cooled helium has a relatively high velocity-- that Doppler limit corresponds to an…
August 21, 2013
I'm writing a bit for the book-in-progress about neutrinos-- prompted by a forthcoming book by Ray Jaywardhana that I was sent for review-- and in looking for material, I ran across a great quote from Arthur Stanley Eddington, the British astronomer and science popularizer best known for his…
August 20, 2013
A little over a year ago, I visited Mark Kasevich's labs at Stanford, and wrote up a paper proposing to use a 10-m atom interferometer to test general relativity. Now, that sounds crazy, but I saw the actual tower when I visited, so it wasn't complete nonsense. And this week, they have a new paper…
August 20, 2013
Element: Rubidium (Rb)
Atomic Number: 37
Mass: two "stable" isotopes, 85 and 87 amu (rubidium-87 is technically radioactive, but it's half-life is 48 billion years, so it might as well be stable for atomic physics purposes.
Laser cooling wavelength: 780 nm
Doppler cooling limit: 140 μK
Chemical…
August 19, 2013
Element: Sodium (Na)
Atomic Number: 11
Mass: one stable isotope, 23 amu
Laser cooling wavelength: 589 nm
Doppler cooling limit: 240 μK
Chemical classification: Alkali metal, column I of the periodic table. Like the majority of elements, it's a greyish metal at room temperature. Like the other…
August 19, 2013
At the tail end of the cold-atom toolbox series, I joked about doing a "trading card" version shortening the posts to a more web-friendly length. In idly thinking about this, though, it occurred to me that if one were going to have cold-atom trading cards, it might make more sense to have them for…
August 18, 2013
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…
August 16, 2013
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…
August 16, 2013
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…
August 15, 2013
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…
