Gravity: The Story So Far

What happens when we try to explain gravity?

The basic issue

Gravity holds us to the Earth and makes apples drop to the ground when they fall off a tree. It controls how the Moon moves round the Earth and how the Moon causes tides on Earth. It controls how the Earth moves round the Sun and how the Sun moves round the Galaxy. But it’s not a force. That was Einstein’s great discovery. How can we say that? Well because you can, at least for a while, simply make it vanish! How do you do that? Just let go! In other words, jump off a building, and you’ll feel no gravity as you fall down (hitting the Earth does not count as falling down). More gently, join a freely orbiting space station crew, and you’ll find life difficult because there will be no felt gravity to hold you down on your seat or to hold your coffee in a cup. In short, what appears to be a gravitational force actually depends, locally at least, on how you are moving. You can make it go away by allowing yourself to fall freely

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Marcel-Marie LeBel 30 September 2020

Gravity is time flowing at different rate here and there. Don't take my word for it; Read Bill Unruh;
‘ .. A more accurate way of summarizing the lessons of General Relativity is that gravity does not cause time to run differently in different places (e.g., faster far from the earth than near it). Gravity is the unequable flow of time from place to place. It is not that there are two separate phenomena, namely gravity and time and that the one, gravity, affects the other. Rather the theory states that the phenomena we usually ascribe to gravity are actually caused by time’s flowing unequably from place to place... “ arXiv:gr-qc/9312027v2 17 Dec 1993

For metaphysics looking for substance and cause, it's all there. Consider the spontaneous dynamic process of the vacuum as Time, the Substance, and the Cause as a difference in the rate of Time. It is complete, considering that a logical system requires that there be only one type of substance/process and only one type of cause in order for the system to be working properly, to be operational.

Dave Cuthbert 23 August 2019

In the first paragraph, referring to gravity, the author says "But it’s not a force" while later -- forced by convention I suppose -- uses the phrase "...gravitational tidal force."