NIST Unveils Chip-scale Atomic Clock

grumling writes "The heart of a minuscule atomic clock, believed to be 100 times smaller than any other atomic clock has been demonstrated by scientists at the Commerce Department's National Institute of Standards and Technology (NIST), opening the door to atomically precise timekeeping in portable, battery-powered devices for secure wireless communications, more precise navigation and other applications. "

Comments

Re:Atomic clock?

[UnknowingFool]

Actually, by definition, something atomic is very small.

Most of the time that is true but in this case, an atomic clock has a very precise meaning in scientific instruments. It is a clock that counts the vibrations of atoms to determine time intervals. Accoring to SI units a second is

a fundamental unit of time in all measuring systems and the SI base unit of time. The name simply means that this unit is the second division of the hour, the minute being the first. The second was defined as 1/86 400 mean solar day until astronomers discovered that the mean solar day is actually not constant (see day). The definition was then changed to 1/86 400 of the mean solar day 1900 January 1. Since we can't go back and measure that day any more, this wasn't a real solution to the problem. In 1967, scientists agreed to define the second as that period of time which makes the frequency of a certain radiation emitted by atoms of cesium-133 equal to 9 192 631 770 hertz (cycles per second). In other words, if we really want to measure a second, we count 9 192 631 770 cycles of this radiation. This definition allows scientists to reconstruct the second anywhere in the world with equal precision.

Up until now atomic clocks like the ones used by NIST were large pieces of equipment. They were highly accurate but not very portable. Before, merchanical watches would lose seconds a day. With the use of quartz in electronic watches that dropped to about a second every 2 months. This lowers that bar even further. I'm not sure for what that level of precision could be used.

Re:Not everybody has permanent connection!

[vadim_t]

You still can do it.

Just run ntpdate when you connect instead of on boot. And kill ntpd before disconnecting. You can do this easily on Linux. On Windows I heard some programs exist to do this as well.

This is not about broadband arrogance anyway. ntpd uses much fewer server resources than ntpdate every second. In fact, many public ntp server administrators often complain about that every hour at :00 minutes they get a ntp version of a slashdotting because people stick ntpdate in crontab.

There are many NTP servers that are free to access out there. Please keep them that way by observing a simple netiquette.

Re:Great for GPS

[Anonymous Coward]

The Navy has been using atomic clocks for decades. Much of the technology in GPS can be traced back to early Navy programs for satellite assisted navigation. When you launch an ICBM from a submarine, you need a very accurate fix on the position of the submarine. Atomic clocks are also as timing references for secure communications links.

In fact, the entire history of accurate time can be attributed to naval navigation.