4 ms·
Should we go ahead and make a SSCT (solar system coordinated time) as well? That way I don't have to constantly be converting lunar timestamps, mars timestamps
by umvi 6y ago
Should we go ahead and make a SSCT (solar system coordinated time) as well?
That way I don't have to constantly be converting lunar timestamps, mars timestamps, etc. back to UTC (or the coordinated time of whichever celestial body I'm currently on) in order to paint a timeline of when events happened between my different devices spread out across the solar system.
- ghshephard 6y agoTime is local to a region though - there isn't any "Solar System Coordinated Time".
- hedora 6y agoJust hold still and avoid gravity wells. It’ll work out.
- nuccy 6y agoWhat is hold still? Relatively to what? Everything moves relatively to each other with a planet, solar system, galaxy, galaxy cluster, supercluster, filament, Universe...
- imoverclocked 6y agoI guess pulsars may be our best bet for a universally coordinated time? We can detect the passage of time in a gravity well and create a well-centric system if need be!
- nuccy 6y agoWell, no, pulsars periods drift due to change of alignment and emission process over time. Thought special and general relativity will drive any "global/solar system/galaxy"-wide precise time useless on long term anyway. The best is to keep track of long enough common measures ("day", "month") with decimal/fractions being connected to actual local times.
- imoverclocked 6y agoThe Earth “day” also drifts over time. If you’ve ever thought today was longer than the last, then you are statistically correct!
- gorgoiler 6y agoAre you saying that a given pulsar acts as a giant sky clock? And that because it is far away — for some large value of far — it means that any clock inconsistencies across the solar system can be compensated for?
- imoverclocked 6y agoPretty much, yes! Obviously the speed of light and orbital motion/distances make things tricky but not impossible. I think I’m also saying that since time passes at different rates in different gravity scenarios, a single external reference may be the best way to coordinate time… even outside of our solar system.
- imoverclocked 6y agoActually, “single external reference” might be wrong here. Using multiple pulsars might give us a better fix for our position +time solution across large distances.
- imoverclocked 6y agoEven cooler is that this has apparently and unsurprisingly already been explored.
- gorgoiler 6y agoThese replies are intriguing, thanks. Do you have some good links / references I can follow?
- imoverclocked 6y agoPulsar positioning system: https://arxiv.org/pdf/1704.03316.pdf https://arxiv.org/pdf/1704.03316.pdf While not a primary source, it's still an answer to absolute time from pulsars: https://physics.stackexchange.com/questions/175981/can-you-use-pulsar-observations-to-determine-absolute-time-how-long-can-you-go https://physics.stackexchange.com/questions/175981/can-you-u...
- d_silin 6y agoI'd say define a "cycle" as greatest common divisor of all planets' rotation periods. Make it an equivalent of "solar system day/hour" or something.
- DavidSJ 6y agoThe problem is these orbital periods are generally not rational multiples of each other, so their GCD is undefined (or 0, in a sense). Some exceptions to this exist due to orbital resonance: Pluto and Neptune are in 2:3 resonance, and in the Jovian system Ganymede, Europa, and Io are in 1:2:4 resonance.
- martinflack 6y agoWouldn't that need accounting for relativity? Distance to the gravity well (sun) affects the physical passage of time for you. Perhaps that's doable, but you can't count a sequence of numbers off and call it a day.