41
votes
Unix Epoch in International Space Station
POSIX time doesn't include leap seconds, and is not implemented the same way in every UNIX, so it routinely gets inconsistent for several seconds every couple of years. It is not a high-precision ...
- 7,942
32
votes
Unix Epoch in International Space Station
No.
Computer clocks are inaccurate. They rely on constant corrections to maintain the correct time. Since their inaccuracy is much bigger than the time speed difference between earth and the ISS, it ...
- 12.6k
28
votes
Unix Epoch in International Space Station
It doesn’t yet matter for most practical purposes. The slowdown from faster motion and speedup from a weaker gravitational field partly cancel out, and the net effect is that time on the ISS is only 0....
- 570
21
votes
Accepted
How can we transmit a date to another species?
The approach taken by Voyager Golden Record is through use of pulsars. Unlike the insane exponents needed to utilize microscopic physical phenomena or planck time, pulsars operate on ~1 second ...
- 55k
8
votes
How can we transmit a date to another species?
Our basic unit of time, the second, is officially defined in terms of physical phenomena, so our messages have to get that across.
If the aliens and ourselves have a compatible understanding of ...
- 169k
8
votes
Unix Epoch in International Space Station
Computers on the ISS do not rely on UNIX/POSIX time, they rely on GPS time.
Broadcast time is the time broadcast from ISS computers that is intended to be indicative of current time.
The broadcast ...
- 2,550
5
votes
Accepted
What is the right way to get Mars' sol?
Reading further down the Wikipedia page, it is clear that no general agreement exists on how the Martian calendar should be described. There are at least seven different proposed calendars, but none ...
- 7,942
4
votes
How can we transmit a date to another species?
One value for time is common for all species, the planck time. It depends only on mathemathical/physical concepts.
But you will have to explain to them the powers of 10 as well because else you would ...
- 141
4
votes
Do the Voyager probes experience time moving faster due to relativity?
You can see this answer for the formulae. We would expect that Voyager 1's local time is faster than Earth time by about one part in one hundred million.
I don't think that the Voyager oscillator is ...
- 58.2k
3
votes
Time when traveling around the speed of light
I think you've misunderstood something; there's no generally accepted model for light-speed-or-faster travel, and so there's no generally accepted model for the passage of time in such a mode.
There ...
- 169k
3
votes
Beating Time Dilation With Time Dilation?
Once you exceed lightspeed, external time would run backwards instead of forwards.
This is where it all falls down. You're applying the laws of relativity to FTL travel, but the laws of relativity, ...
- 1,073
3
votes
How can we transmit a date to another species?
One option nobody else mentioned is cosmic microwave background. If you can encode the current temperature of the universe in a way the receiving aliens understand, they will either have a record of ...
- 1,326
3
votes
How are Experienced and Observed Mission Elapsed Times defined? (EMET & OMET)
How are EMET and OMET defined?
I understood the answer to be an example of what the timing on an interstellar mission would look like. In other words, the definitions of EMET and OMET are that answer....
- 18.6k
3
votes
Unix Epoch in International Space Station
Unix time is (sloppily) based on UTC, which in turn is based on TAI (international atomic time). TAI is a coordinate time, an implementation of TT (terrestrial time) defined to be equal to proper SI ...
- 3,304
2
votes
What is the right way to get Mars' sol?
The Mars Solar Date system is defined by Michael Allison and Megan McEwen in their paper "A post-Pathfinder evaluation of aerocentric solar coordinates with improved timing recipes for Mars ...
- 11.2k
2
votes
Why would light take time to reach distance if space and time are relative?
The distance (and time) shrink from the viewpoint of the fast-moving object, but not from the viewpoint of a stationary observer.
- 19.6k
1
vote
How can we transmit a date to another species?
Time-keeping is a particularly interesting subject for me. There are multiple ways you can communicate a date, and some sort of system of keeping time to reference that to. Some constants in nature ...
- 59
1
vote
How can we transmit a date to another species?
Well, the speed of light is never going to change. That being the case, one method could be to use light years as a means to calculate time.
'x light years from now' could be the way to specify a ...
- 111
1
vote
Can the Oberth effect cause space-time distortions?
Can the Oberth effect cause space-time distortions?
No, but the mass(es) used for the maneuver might.
Note that the velocity of the spacecraft performing the maneuver might cause a slowing of it's ...
- 1,522
1
vote
Accepted
Time dilation between Earth and a similar planet revolving around a supermassive Black hole
You are a lot further down a gravity well when you are in the vicinity of a black hole. That alone can explain time dilation factors without even considering the extreme velocity that object must ...
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