Comment by defrost | Hacker News Reader

Comment by defrost | Hacker News Reader

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You know what absolutey is inherent to imekeeping?

* Drift between terresterial and sidereal time,

* Drift between terresterial ground level (1G gravity mean 'surface') and orbiting satellite (eg: GPS time)

* Differing frames of time reference best suited for different tasks.

Common computer time server synced time is based on the nominal notion of "mean noontime" UTC .. or the rotation time of the earth to move from Greenwich "pointing at the sun" to again "point at the sun" (perhaps surprising to some NOT a full "360 degree" rotation as the earth has moved forward on its orbit).

Myths about time that programmers should know is a good read .. eventually drift between systems must be addressed ( GPS sats use "epoch time" (local atomic clock ticks) lapsed "per week" and GPS recievers reconcile relativistic drift using broadcast corrections ).

Any significant scientific data collection program (geophysics, astronomy) required the use of some form of "epoch time" with accurate local clocks not synced to UT | GMT | Zulu time servers.

Your apparent desire to not deal with adjustments on the order of a second during your lifetime is simply pushing the problem down the road until it's a case of reconciling hours .. or even 11 days (as has already happened in history).

All those things are definitely important, and leap seconds don't help with any of them.

> Your apparent desire to not deal with adjustments on the order of a second during your lifetime is simply pushing the problem down the road until it's a case of reconciling hours .. or even 11 days (as has already happened in history).

An hour, or fraction of an hour, is significantly easier to reconcile. Even assuming we stick with the same system for that very large number of years.

We've stuck with noon centred based timekeeping for two thousand odd years now, I suspect it'll remain that way for a few hundred years more.

Fractions of hours require the same effort of understanding the issue that seconds do.

Where it matters (my field) we use absolute lapsed seconds in a specific framework and don't rely on sync'ing to UTC.

You can be noon centered without sticking to the same reference observatory forever.

Fractions of hours are just a time zone. Time zone changes happen all the time. Much easier than shifting the underlying clock.

You're not demonstrating much grasp of the actual issues.

If you have a genuine interest there are some decent starting links in this thread that you might pursue.

What a useless response. I address very specific points with clear arguments and you just tell me to do general research?

> to again "point at the sun" (perhaps surprising to some NOT a full "360 degree" rotation

It's actually more than a 360 degree rotation because the earth rotates in the same sense that it revolves. So the sidereal day (1 earth rotation in physics sense) is ~ 23h 56m, and the 24 hour period is over-rotation to bring the sun back into same position, and that's more than 360 degrees of rotation.

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