I’ve been really busy with year-end wrap-up stuff, but have also posted a bunch of stuff at Forbes. which I’ve fallen down on my obligation to promote here… So, somewhat belatedly, here’s a collection of physics-y stuff that I’ve written recently: — Using Atoms To Measure Tiny Forces: A post reporting on some very cool […]
Category: Cold Atoms
The Birth of BEC
I’m massively short on sleep today, and wasn’t going to blog until I saw somebody on Facebook mention that June 5th 1995 is the date of record for the first Bose-Einstein condensate at JILA in Boulder. I couldn’t let that pass, so I wrote it up for Forbes: Twenty years ago, in the summer of […]
How Not to Control the Weather for Your Dog
I’m rooting around in my bag for a pen, and pull out a laser pointer by mistake. Since I’d really prefer not to be grading, I flip it on and shine it on the floor next to the spot where Emmy is half-dozing. She immediately leaps up (she’s pretty spry for a dog of 12…), […]
Super Bowl Athletes Are Scientists At Work
I wrote up another piece about football for the Conversation, this time drawing on material from Eureka, explaining how great football players are using scientific thinking: Seattle Seahawks cornerback Richard Sherman gets called a lot of things. He calls himself the greatest cornerback in the NFL (and Seattle fans tend to agree). Sportswriters and some […]
Small College, Exotic Particles
Topping the looooong list of things I would give a full ResearchBlogging write-up if I had time is this new paper on a ultra-cold atom realization of “Dirac Monopoles”. This is really cool stuff, but there are a lot of intricacies that I don’t fully understand, so writing it up isn’t a simple matter. The […]
Laser-Cooled Atoms: Ytterbium
Element: Ytterbium (Yb) Atomic Number: 70 Mass: Seven “stable” isotopes, from 168 to 176 amu. Two of those are nominally radioactive, with half-lives vastly in excess of the age of the universe. Laser cooling wavelength: 399 nm and 556 nm. Doppler cooling limit: 690 μK in the UV and 4.4 μK in the green. Chemical […]
Laser-Cooled Atoms: Cesium
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. Still explodes violently in water, though. Other properties […]
Laser-Cooled Atoms: Chromium
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 classification: Transition metal, smack in the middle of the periodic table. […]
Laser-Cooled Atoms: Lithium
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 reactive than any of the others, so the […]
Laser-Cooled Atoms: Francium
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 classification: Alkali […]