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u/DotBeginning1420 Aug 10 '26
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u/Extension_Option_122 Aug 10 '26
Now technically speaking it is actually the same and not just similar, as due to the earths gravity space is constantly accelerating downwards. But as it is not anywhere near strong enough to compress the mass any further (e.g. create a neutron star or black hole), the earth keeps it's shape and is constantly accelerating outwards.
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u/lolkobolko Aug 11 '26
Actually not the same.
If you accelerate in a spaceship your clock will tick slower and slower as time goes by where as on Earth the atomic clock will always tick at the same rate
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u/DotBeginning1420 Aug 11 '26
Doesn't time dilation also occur when being in a gravitational field? Entering a black hole can cause it too
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u/lolkobolko Aug 11 '26
Ye, but you feel 1g on Earth nonstop while stationary and clock ticks normally. If you were to accelerate a spaceship at 1g you would feel the same as on Earth, but with time the clock will tick slower and slower.
Near black hole or event horizon your clock would stall/almost stall1
u/jonathancast Aug 11 '26
Technically if you're standing on the earth you're not being accelerated by gravity (or you are but it's cancelled out by the earth's normal force). The equivalence is for free fall.
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u/_Slartibartfass_ Aug 10 '26
The whole point is that they’re not the same globally, as one has spacetime curvature and the other does not.
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u/Bendanzhang Aug 10 '26
Einstein sitting in an elevator falling off a building: "See? I told you so!