

Ask HN: Is there a universal time measure to use as a spacefaring civilisation? - cbovis

I&#x27;ve been watching the Human Universe series recently and it got me thinking as to how we would measure time if we were to become a spacefaring civilisation.<p>As I see it there are a couple of problems,<p>1. Once we colonise another planet our concept of time (e.g. days, years etc) will be different to that of life on earth due to the shift in a planets orbit. Presumably every planet would require it&#x27;s own measurement of time e.g. a martian year so that those living there can keep time in relative terms. We&#x27;ll want a universal time however to synchronise events in time across all of our colonies. This would be the easiest problem as we can base it off of earth time.<p>2. If we were to encounter intelligent extra terrestrial life then we would need to agree on a concept of universal time to explain the history of our&#x2F;their planet &amp; species.<p>Does an idea for this universal measurement of time currently exist? If not then how would you expect it to look?
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mappu
Time is observer-dependent, any universal measurement of time is going to be
somehow "inobjective" given relativity (and FTL travel).

I haven't seen the Human Universe but e.g. Voices of a Distant Star, A Fire
Upon The Deep, and Interstellar all touch on time dilation as major plot
points.

Gundam standardised space colonies on the Universal Century (earth time) but
that was over much shorter distances.

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ararar
"inobjective"?

The word you want is 'subjective'.

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ararar
There is no reason two or more observers can't share a synchronized clock so
long as it is outside their respective frames of reference. Example, a far
away, mutually observable pulsar.

