Playing With Atomic Clocks At Home 167
Wired is running a profile of the Time Nuts, a small group of people who buy surplus precision time equipment — cesium clocks for example — on eBay and keep really accurate time, because they can. The article quotes Tom Van Baak, who has outfitted a time lab superior to those of many small countries: "If you have one clock... you are peaceful and have no worries. If you have two clocks... you start asking, 'What time is it, really?'"
Re:Please read the article (Score:4, Informative)
Half way solution: GPS (Score:5, Informative)
No no no, the saying is... (Score:5, Informative)
Re:The real reason (Score:5, Informative)
Keeping track of time (Score:2, Informative)
International Atomic Time (TAI, from the French name ) is a high-precision atomic time standard that tracks proper time on Earth's geoid. It is the principal realisation of Terrestrial Time. As of 2007 TAI is exactly 33 seconds ahead of UTC: 10 seconds' initial difference at the start of 1972, plus 23 leap seconds in UTC since 1972. TAI in this form was synchronised with Universal Time at the beginning of 1958, and the two have drifted apart ever since.
Accurate time is very important for computer systems/networks. The best way to keep track of time is to install a local timeserver which synchronizes against a reliable public timeserver like pool.ntp.org. The local time server can be used to synchronize other computers you might have.
Re:Half way solution: GPS (Score:3, Informative)
Re:Half way solution: GPS (Score:1, Informative)
How many upstream servers do you sync to? "Bad internet weather" shouldn't desync your NTP server given enough peers to talk to. My local NTP server syncs up to five remote servers spread over three continents, and the only event that my NTP server process noticed was my DSL modem melting down.
My long-term NTP traffic rate is maybe 1 packet every 5 minutes, so it takes a hella big network disruption to make NTP take notice.
Re:I don't get it. (Score:4, Informative)
They are calling these "clocks" only because that is what the typical reader understands. A better term is "frequency standard". There are many uses for a stable frequency, the most common one is running a microwave transmitter. This is the major source of the surplus devices too, from cell towers. As the phone companies modernize equipment these "clocks" find their way to eBay and then into people's houses.