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Playing With Atomic Clocks At Home

Posted by kdawson on from the as-i-was-walking-down-the-street-one-day dept.

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?'"

5 of 167 comments (clear)

  1. Re:Please read the article by brunes69 · · Score: 3, Informative

    You do know that they proved this like 60 years ago right, when the first Atomic clocks were produced.... In addition there is an atomic clock on the shuttle. The time difference between it and it's perfectly synchronized counterpart on earth is very visible.

  2. Half way solution: GPS by FridayBob · · Score: 4, Informative

    NTPD isn't good enough for me -- bad weather on the Internet has caused my server to loose synchronization one too many times, which can be mighty irritating when comparing your log files with those of other systems. On the other hand, acquiring an atomic clock seems a bit over the top to me. So, I figured a good compromise solution would be to connect a GPS receiver to my serial port and synchronize NTPD to that. I've ordered a Garmin GPS 18 OEM LVC that I will receive later this month (hopefully). According to these instructions it's not that difficult to set up, while the result is microsecond precision on Linux 2.6 and nanosecond precision on BSD -- good enough for me. All you need to do is to make sure that your GPS device has a reasonable view of the sky.

  3. No no no, the saying is... by Relic+of+the+Future · · Score: 5, Informative

    They got the saying all wrong. It goes "A man who wears one watch always knows what time it is; a man who wears two watches is never sure."

    --
    Those who fail to understand communication protocols, are doomed to repeat them over port 80.
  4. Re:The real reason by timeOday · · Score: 4, Informative

    Isn't it obvious? It wasn't relativity, the family lived an extra 22 milliseconds because they drove up a mountain
    After noticing your comment I read the whole article just because 22 ms sounded like an impossibly large relativistic effect for a car. It was actually 22 nanoseconds. You're off by a factor of a million.
  5. Re:I don't get it. by ChrisA90278 · · Score: 3, Informative

    What's the fascination with uber-accuracy at home?

    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.