Feeds

Boffins build super-accurate atomic clock

300 million years without winding

Business security measures using SSL

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. ®

Providing a secure and efficient Helpdesk

More from The Register

next story
PORTAL TO ELSEWHERE scried in small galaxy far, far away
Supermassive black hole dominates titchy star formation
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Edge Research Lab to tackle chilly LOHAN's final test flight
Our US allies to probe potential Vulture 2 servo freeze
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
Bacon-related medical breakthrough wins Ig Nobel prize
Is there ANYTHING cured pork can't do?
Cracked it - Vulture 2 power podule fires servos for 4 HOURS
Pixhawk avionics juice issue sorted, onwards to Spaceport America
City hidden beneath England's Stonehenge had HUMAN ABATTOIR. And a pub
Boozed-up ancients drank beer before tearing corpses apart
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.
Protecting users from Firesheep and other Sidejacking attacks with SSL
Discussing the vulnerabilities inherent in Wi-Fi networks, and how using TLS/SSL for your entire site will assure security.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.