[ghkbrew]

My calculations says that moving 1cm up or down earths gravity well (at the surface) changes the acceleration of gravity about 5x more than the acceleration you'd feel from a 100kg mass 1m away.

Assuming my math is correct, it's already affected by nearby human scale masses, for certain values of "near".

[pfdietz]

I believe the time dilation is caused by differences in gravitational potential, not gravitational acceleration, so it would be even worse than that.

[GolDDranks]

Huh, I was thinking that it's accelerated gravitational frames that cause the dilation, and I've encountered a lot of statements that argue the same. This is from wikipedia: "This is because gravitational time dilation is manifested in accelerated frames of reference or, by virtue of the equivalence principle, in the gravitational field of massive objects."

However, according to that logic, an object located in a cavity in the center of earth should experience no more dilation than an object outside the earth's potential well, because the gravitational forces / curvature gradient cancels out, and should be zero. But that isn't the case according to the same sources, for example, Wikipedia says' "Relative to Earth's age in billions of years, Earth's core is in effect 2.5 years younger than its surface."

Something's not right about how we verbalize this story about gravity