Wired has an interesting article on the atomic clocks they are working with at the National Institute of Standards and Technology (NIST) in Boulder.
A part that made me smile, was the description of the Time and Frequency Division’s facilities:
With its fading beige walls and checkered linoleum floors, NIST’s Time and Frequency Division hardly invites a sense of precision. Distracted-looking scientists in slightly rumpled button-downs roam the halls, occasionally sparing a quizzical look for outsiders. Graduate students wander in funny T-shirts, passing offices and labs crammed with manila folders and well-used tools, while cables and pipes zigzag across the ceiling.
That is the exact description for every laboratory space at every university I have ever attended or visited. Seriously, all of them. The University of Colorado (both the Boulder and Denver campuses), Colorado State University, The University of Texas at Austin, and even MIT. It must be some axiom to the often quoted theorem “The worse you look, the smarter they think you are.” but applied to lab space.
The description of their atomic clock also sounds like a grad student’s project:
a jumble of polished lenses and mirrors converging on a gleaming silver cylinder, all protected by a tent of clear plastic nailed to a frame of two-by-fours.
Yup. All they are missing is the aluminum foil, and they’re set!
All facilities observations aside, the article points out some really cool things. The current precision of the clock described above is 10-15 seconds. That is about a thousand-million-millionth of a second. In that amount of time, light travels about 300 nanometers. For comparison, the width of a human hair is about 80,000 nanometers. At that precision, they have to compensate not only for the relativistic effects of the earth’s rotation and orbit and such, but the changes in that velocity by relocating from one floor to another. Mind boggling. And it doesn’t stop there. The system they are currently working on has a target precision of 10-18 seconds. A thousand times more precise.
The are also working on making these super-precise atomic clocks smaller. Not just a little bit, either.
“We’re trying to shrink down … with the whole thing the size of a sugar cube and able to run on AA batteries,” says O’Brian. The most obvious application is making GPS receivers much more accurate, but a tiny atomic clock would have other applications as well.
At the University of Pittsburgh last fall, researchers used a NIST-produced atomic clock the size of a grain of rice to map variations in the magnetic field of a mouse’s heartbeat. They placed the clock 2 mm away from the mouse’s chest, and watched as the mouse’s iron-rich blood threw off the clock’s ticking with every heartbeat.
There is a lot of cool things going on in those cold-war era concrete buildings in Boulder, that is for sure!
