4 ms·

Can't you solve that by just picking a reference frame though?

• ianopolous 8y ago
  You need a quite elaborate system of a grid of synchronized, stationary clocks and rods to correctly define a reference frame, which is worse than what's required to come up with a "good enough on earth to some time resolution" true time.
  • ianopolous 8y ago
    To be clear this is pretty much exactly what the system of GPS satellites does, but without physical rods, and it is very expensive to construct and maintain. This works fine to a certain accuracy as long as you restrict your application to staying on earth.
• xenadu02 8y ago
  Yes, and we all pick the Earth’s gravity well as our reference frame. Differences due to elevation and latitude are too small to measure for purposes of transaction clocks.
• jonas21 8y ago
  yeah, I’m pretty sure TrueTime is only defined on Earth, and GPS satellites do take relativity into account in their design. http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps.html http://www.astronomy.ohio-state.edu/~pogge/Ast162/Unit5/gps....
• hinkley 8y ago
  HTTP has had a reference frame since 1.0. It’s still one of my favorite features of just about any protocol ever. Cache headers can set expiration times or offsets, but the client and server both send their own time stamp in the message. So when the server says “expire this at noon” but your laptop’s clock is five minutes slow or three time zones away, you can still figure out what the server meant by noon because the server tells you what time it thinks it is now. The accuracy is limited by network delays but for the problem space getting the right answer to the nearest second is still pretty damned good.