If they are nearby, in our galaxy, and not moving at some great speed relative to us, their clocks would run at about the same rate as us.
Not exactly the same. Even a clock at the top of a building runs a bit faster than a clock in the basement due to the "gravitational time dilation".
This effect is easily measurable with sensitive clocks, and they have to take account of it for the GPS satellites.
A satellite in orbit around Earth runs slightly slower because of its faster orbit. But also slightly faster because it isn't as deep into the Earth's gravitational well as us. Combination of the two is a net gain as in this diagram made by a wikipedia editor:
So you'll get differences like that for sure, there a gain of 100 picoseconds in a second is about 0.003 seconds in a year.
So anyone living in a deep gravitational well will have slowed down time. If they live right close to a black hole event horizon, if such exist, and supposing they had the technology to live there, they could experience just days passing when we experience thousands of years.
Also if traveling at high speed, a significant fraction of the speed of light, again their clocks run slower than ours.
But apart from that, their time would be very much like ours, but there would be these small discrepancies that would be of relevance to physicists and such like.
They might have a very different "time sense" though. Some fun sci. fi stories about that. After all sloths and snails live life in the slow lane, while flies and birds surely have a more speeded up sense than us. Humming birds, and bees and such like can respond to things before we even notice they are happening.
It might be quite challenging to carry out a conversation with an ETI with a radically different time sense, slower or faster.
Robert Forward's Dragon's egg book explores that idea with beings with a hugely speeded up time sense.
Then in the other direction, Eric Frank Russell's The Waitabits and
Roger Zelazny. The Great Slow Kings
For more examples, see Themes : Time Distortion : SFE : Science Fiction Encyclopedia
As the other answers here say, the seasons and day length and so on would be almost sure to be different so they would have different calenders and clocks.
Not exactly the same. Even a clock at the top of a building runs a bit faster than a clock in the basement due to the "gravitational time dilation".
This effect is easily measurable with sensitive clocks, and they have to take account of it for the GPS satellites.
A satellite in orbit around Earth runs slightly slower because of its faster orbit. But also slightly faster because it isn't as deep into the Earth's gravitational well as us. Combination of the two is a net gain as in this diagram made by a wikipedia editor:
Orbit times (by Unitsphere )
So you'll get differences like that for sure, there a gain of 100 picoseconds in a second is about 0.003 seconds in a year.
So anyone living in a deep gravitational well will have slowed down time. If they live right close to a black hole event horizon, if such exist, and supposing they had the technology to live there, they could experience just days passing when we experience thousands of years.
Also if traveling at high speed, a significant fraction of the speed of light, again their clocks run slower than ours.
But apart from that, their time would be very much like ours, but there would be these small discrepancies that would be of relevance to physicists and such like.
They might have a very different "time sense" though. Some fun sci. fi stories about that. After all sloths and snails live life in the slow lane, while flies and birds surely have a more speeded up sense than us. Humming birds, and bees and such like can respond to things before we even notice they are happening.
It might be quite challenging to carry out a conversation with an ETI with a radically different time sense, slower or faster.
Robert Forward's Dragon's egg book explores that idea with beings with a hugely speeded up time sense.
Then in the other direction, Eric Frank Russell's The Waitabits and
Roger Zelazny. The Great Slow Kings
For more examples, see Themes : Time Distortion : SFE : Science Fiction Encyclopedia
As the other answers here say, the seasons and day length and so on would be almost sure to be different so they would have different calenders and clocks.
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
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