3 ms·

Since it is obvious it wouldn't last 300B years, how do they plan to synchronise time on a replacement clock? And if they can't do that with equal precision, wh

Since it is obvious it wouldn't last 300B years, how do they plan to synchronise time on a replacement clock? And if they can't do that with equal precision, what good is having it at all?

bagels 5y ago
That'd only matter if you're trying to make measurements across the time where you switch from one clock to another. If you use it for 10 years to study gravitation waves, it'd be fit for that purpose since you'd be comparing intervals from the same clock.
- edf13 5y ago
  But at which point does the loss of time kick in for such experiments? So you lose a second over a vast timescale but the micro incremental losses still count right?
  - MattPalmer1086 5y ago
    I think the point is that it provides very precise measurements for each independent experiment. I don't think anyone is trying to track the absolute time elapsed over long periods with this clock since it started.
fsh 5y ago
These experimental clocks are generally not used for time keeping. They are room-filling atomic physics experiments, which are not reliable enough for permanent operation. It is better to think of them as frequency standards. This means that the clock laser will have the same frequency in a month as it does today (to a very high level of precision). If you have multiple such frequency standards, you can put them in different locations and compare their frequencies via optical fiber links. The frequencies are affected by gravitational time dilation, so this can be used for mapping the earth's gravitational potential. In the future, it might also allow detecting gravitational waves.
hughrr 5y ago
There are time and frequency standards that people rely on for all sorts of things. This sort of equipment can be used to calibrate the current time and frequency standards. Also for high precision physics measurements etc. Clocks aren’t really that important with 10ms resolution at best, although it can be fun playing with old time standard kit http://www.leapsecond.com/pages/atomic-bill/ http://www.leapsecond.com/pages/atomic-bill/

Since it is obvious it wouldn't last 300B years, how do they plan to synchronise time on a replacement clock? And if they can't do that with equal precision, what good is having it at all?

bagels 5y ago

That'd only matter if you're trying to make measurements across the time where you switch from one clock to another. If you use it for 10 years to study gravitation waves, it'd be fit for that purpose since you'd be comparing intervals from the same clock.

edf13 5y ago
But at which point does the loss of time kick in for such experiments? So you lose a second over a vast timescale but the micro incremental losses still count right?
- MattPalmer1086 5y ago
  I think the point is that it provides very precise measurements for each independent experiment. I don't think anyone is trying to track the absolute time elapsed over long periods with this clock since it started.

fsh 5y ago

These experimental clocks are generally not used for time keeping. They are room-filling atomic physics experiments, which are not reliable enough for permanent operation. It is better to think of them as frequency standards. This means that the clock laser will have the same frequency in a month as it does today (to a very high level of precision). If you have multiple such frequency standards, you can put them in different locations and compare their frequencies via optical fiber links. The frequencies are affected by gravitational time dilation, so this can be used for mapping the earth's gravitational potential. In the future, it might also allow detecting gravitational waves.

hughrr 5y ago

There are time and frequency standards that people rely on for all sorts of things. This sort of equipment can be used to calibrate the current time and frequency standards. Also for high precision physics measurements etc. Clocks aren’t really that important with 10ms resolution at best, although it can be fun playing with old time standard kit http://www.leapsecond.com/pages/atomic-bill/ http://www.leapsecond.com/pages/atomic-bill/