atomic clock

I have to admit, I'm writing this one up partly because it lets me use the title reference. It's a cool little paper, though, demonstrating the lengths that physicists will go to in pursuit of precision measurements. I'm just going to pretend I didn't see that dorky post title, and ask what this is about. Well, it's about the trapping and laser cooling of thorium ions. They managed to load thorium ions into an ion trap, and use lasers to lower their temperature into the millikelvin range. At such low temperatures, the ions in the trap "crystallize." So, they've demonstrated that if you get…