Feeds

Boffins build super-accurate atomic clock

300 million years without winding

Build a business case: developing custom apps

The atomic clocks currently used for regulating international time zones are great and all, but who has the time every few million years to adjust them?

Fortunately, physicists in the US have figured out how to control seemingly "forbidden" collisions between neutral strontium atoms to make a clock that neither loses nor gains a second in more than 300 million years.

The research was done by the folks at JILA, one of the country's leading physical science research institutes, jointly run by the University of Colorado and the National Institute of Standards and Technology. Their latest findings are described in the April issue of the journal Science.

Like other atomic timepieces, JILA's strontium-based clock measures time by harnessing the natural - and conveniently consistent - vibrations of atoms.

JILA's clock - which it's been improving on for the last couple of years - traps a whole bunch of super-cooled strontium atoms in an optical grid of overlapping infrared beams. Strontium's "ticks" are measured by bathing the atoms in light from a separate red laser tuned to a frequency that prompts a uniform jump between two energy levels.

Using a whole bunch of atoms to measure the ticks increases the precision of the clock's signal, but the atoms tend to want to mingle - which messes with their internal energy states and minutely reduces overall accuracy.

Strontium belongs to a class of atoms called fermions. According to quantum physics, fermions can't occupy the same energy state and location at the same time. Therefore fermions in identical energy states can't collide. The difficulty is, in practice with JILA's clock, they do.

Scientists at JILA have now figured out that all this laser-to-atom action in the clock introduces a very small degree of inconsistency in the atoms. And once fermions are even slightly distinguishable, collisions can occur.

JILA's latest clock suppresses the atomic mayhem by reducing the strontium atoms' temperature to a few millionths of a degree closer to absolute zero and increasing the grid depth. The difference improves their previous version, which they introduced in 2008 by 50 per cent - resulting in a very impressive feat of not needing significant winding for more than 300 million years.

Ultra-precise clocks like this are actually quite useful for applications like improving the synchronization of telecom networks and deep-space communications. Also, casually mentioning that you made a clock that's accurate to a second for 300 million years is almost guaranteed to get you laid. ®

Securing Web Applications Made Simple and Scalable

More from The Register

next story
Asteroid's DINO KILLING SPREE just bad luck – boffins
Sauricide WASN'T inevitable, reckon scientists
BEST BATTERY EVER: All lithium, all the time, plus a dash of carbon nano-stuff
We have found the Holy Grail (of batteries) - boffins
The Sun took a day off last week and made NO sunspots
Someone needs to get that lazy star cooking again before things get cold around here
Boffins discuss AI space program at hush-hush IARPA confab
IBM, MIT, plenty of others invited to fill Uncle Sam's spy toolchest, but where's Google?
Famous 'Dish' radio telescope to be emptied in budget crisis: CSIRO
Radio astronomy suffering to protect Square Kilometre Array
Bad back? Show some spine and stop popping paracetamol
Study finds common pain-killer doesn't reduce pain or shorten recovery
Forty-five years ago: FOOTPRINTS FOUND ON MOON
NASA won't be back any time soon, sadly
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.