# How does general relativity explain tides?

How general relativity explains tides using spacetime curvature? and if the full moon can affect water, inside the international space station did the ever observe small things like water droplets move towards the moon or the entire station move to a path closer to moon? even on earth when the full moon arises why we cant see least any small objects which have less density than water but higher than the atmospheric air move towards the moon. i know that there were two tides can be seen cause earth moves towards the moon so may be that's the case we don't see small items moving up cause the earth is moving with those too. just need a clarification.

• Why do you think it explains it any differently from Newtonian gravity? Newtonian gravity is a valid limit of general relativity in situations where the relativistic effects are neglegible, what reason do you have to believe they aren't in this case? Oct 8, 2021 at 15:23
• – J.G.
Oct 8, 2021 at 15:38
• @ACuriousMind Not all Newtonian and post-Newtonian theories of gravity necessarily have the same predictions about tides. Famously, Whitehead's theory was problematic there (though that's been debated). Vector-tensor theories are surprisingly sensitive re: tides, too.
– J.G.
Oct 8, 2021 at 15:42
• Re, "or the entire station move to a path closer to moon ?" That phenomenon is called perturbation, and I don't know this for a fact, but I strongly suspect that it's measurable. Oct 8, 2021 at 15:50
• P.S.: Water in the Earth's oceans does not "move toward the moon." It experiences a daily cycle of very small changes in its weight as the Earth rotates in the presence of the gravitational attraction from the Moon and Sun. Those cyclic changes constitute a forcing function that causes the water in the oceans to slosh around in complex ways. The complexity is due to the shapes of the various ocean basins and bays around the world. Oct 8, 2021 at 15:57