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
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