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Objects far apart may be traveling faster than the speed of light but once the universe reaches equilibrium won't there be intermediate masses that gravity will

Objects far apart may be traveling faster than the speed of light but once the universe reaches equilibrium won't there be intermediate masses that gravity will be able to travel through? I was also under the impression that an expansion of space would just reduce the gradient of the gravity along that space and not inhibit its propagation. If like a bubble space has some form of surface tension then would there be a point that it can no longer expand? Gravity could then become dominant and force the contraction. -edit-> I guess that wouldn't contract the space though just the matter? I promise I'm not being pedantic or contrarian for the sake of it but to further my knowledge, thanks for your input!

fhars 6y ago
There is no "equilibrium" the universe is moving towards, it is just expanding, and the "intermediate masses" are getting more spread out the more the universe expands. The expansion doesn't inhibit the propagation of gravity, it just makes the attraction between masses weaker and weaker the further they are apart, until they are so far apart that the space between them expands faster than the speed of light, at which moment they will no longer be able to interact with another, neither by light nor by gravity, and the contracting effect of gravity becomes weaker and weaker the larger the universe becomes. According to out current best cosmological model, Lambda-CDM (which, admittedly, is mostly a phenomenological model for things we only half understand, but still describes our current observations better than any competing model), gravity used to be the dominant force in the universe when it was smaller so that the masses were closer together until quite recently. But now it looks like the expansion, the "Lambda" term in "Lambda-CDM", the cosmological constant of general relativity, has become the dominant force in the universe, and the universe is slated to expand ever faster. It could start to contract if Lambda were closer to zero, but it currently doesn't look like it might move there. But then we don't know why Lambda it there at all and what causes it not to be zero in the first place, as everyone expected it to be until about two decades ago (Einstein himself thought of the introduction of the term into his theory as a blunder, as it would obviously be zero in any sane universe.)
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fhars 6y ago

There is no "equilibrium" the universe is moving towards, it is just expanding, and the "intermediate masses" are getting more spread out the more the universe expands. The expansion doesn't inhibit the propagation of gravity, it just makes the attraction between masses weaker and weaker the further they are apart, until they are so far apart that the space between them expands faster than the speed of light, at which moment they will no longer be able to interact with another, neither by light nor by gravity, and the contracting effect of gravity becomes weaker and weaker the larger the universe becomes. According to out current best cosmological model, Lambda-CDM (which, admittedly, is mostly a phenomenological model for things we only half understand, but still describes our current observations better than any competing model), gravity used to be the dominant force in the universe when it was smaller so that the masses were closer together until quite recently. But now it looks like the expansion, the "Lambda" term in "Lambda-CDM", the cosmological constant of general relativity, has become the dominant force in the universe, and the universe is slated to expand ever faster. It could start to contract if Lambda were closer to zero, but it currently doesn't look like it might move there. But then we don't know why Lambda it there at all and what causes it not to be zero in the first place, as everyone expected it to be until about two decades ago (Einstein himself thought of the introduction of the term into his theory as a blunder, as it would obviously be zero in any sane universe.)

deleted 6y ago
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