Can we compress space without gravity

Does the mass compress spacetime?


The presence of matter does not distort space-time. You could make a shell of matter and space-time on one side could be perfectly flat no matter how close you get to the shell.

The spacetime warps, of course. A wave of distorted spacetime could propagate through a universe that is without matter everywhere and always was and always will be. It is natural for space-time to be warped.

What is important or, more precisely, what Cause tension, pressure, pulse density, energy density and energy flow , is that regions of naturally curved spacetime that could normally touch meet each other. In many systems, the energy density is the largest factor and the energy density is nearly proportional to the mass density.

The way space-time got so curved outside of a star was because there used to be a little curvature and some matter. And matter was slow enough relative to one another that the slight curvature allowed it to compress. And since it compressed the type of curvature on the outside, it could no longer switch to a different type than it was then.

So the type of outside had to extend inward, and it was a type that has a tighter curvature. And the gas collapsed more and that process continued.

Finally, when all the matter that causes our sun to collapse is as small as Earth's orbit, space-time here was as curved as it is now. The gas continued to collapse so that the type of curvature extends to the surface of the sun, while it used to be the type that was outside the entire solar system and the curvature there was weaker, but the same type as what we know Here.

After that, you seem to be fine. It's not the presence of matter here and how that matters, it's the curvature here and now that matters. And curvature exists and spreads and matter affected it when it passed through a long time ago.

The theory of relativity suggests that time moves at different heights from the earth's surface at different speeds, the closer the core gets, the slower time becomes.

This is a simplification that has gone too far. There is no such thing as a global time that ticks at different speeds in different places. Instead, clocks move through space and time, and when they tick depends on where they are and how they move.

I'm bringing this up about the next mistake you're about to make.

In the case of a singularity, time slows down significantly as an observer approaches the center of the curvature.

No A bare singularity doesn't do that. And a singularity behind an event horizon has infinite time dilation relative to infinity on the horizon, not the singularity. So you are confusing a horizon and a singularity.

Joshua Dannemann

As informative as this answer is, I had a curiosity equivalent to that of the questioner. When space-time warps around a massive body, is it like expanding it or concentrating inward? In other words, is the concentration of spacetime closer to a massive body "denser" or more dispersed than would be the case with the age-old analogy of a bowling ball on a trampoline? In this case, the actual fibers of the trampoline are drawn outwards. The opposite of focusing inward would be like hitting a blanket in the middle.

Joshua Dannemann

I wanted to say "pinch", not "hit".

Ben Crowell

IMO, this is not a very good verbal description of the structure of the Einstein field equations. Many of the statements seem either incorrect or incomprehensible. Example: What is important, or more precisely what tension, pressure, momentum density, energy density and energy flow do, is that regions of naturally curved spacetime that could normally touch meet one another. I can't make heads or tails out of it.

PM 2ring

I am with Ben. What on earth does "regions of naturally curved spacetime that might normally touch" mean?


Hello Timaios, this is really a good input. I'm assuming: Why can't space-time be naturally distorted AND neither can mass distortion? Some earlier forces, of course, had to forgive it in the first place. I would suspect that spacetime is a dynamic topology that is acted upon by numerous forces at random. Of course, my simplifications are just that, and that is the danger in a thought experiment, they are analogies. Regardless of how, time passes at the same rate for the local observer, but it can be faster or slower for others. They are relative frames of reference.


General relativistic curvature is "intrinsic curvature" - that is, no other dimension is required "to curve". The warping / bending takes place in a direction that can be integrated into our known x, y, z, t.

(Another way the age-old analogy of a ball rolling a warped 2D sheet is flawed. If the sheet wasn't warped in its own plane, that would be better.)

Such an intrinsic curvature inevitably leads to a higher and lower "density" of spacetime when it is different in different places. That is, identical objects appear to converge or diverge on parallel free fall paths when they encounter such a curvature. You seem to have been attacked by a force.

We already know the concept of the potential energy of gravity (the metric tensor in GR). For a reference mass / energy, this could be interpreted as a measure of the "density" of space-time, with differentials representing areas with higher curvature and higher apparent gravitational force. However, it would be wrong to assume that gravitational potential (not rate of change in gravitational potential) is proportional to curvature / force.

Elio Fabri

Attention catalyst! There is very little to salvage in the answers I read before mine. It also depends, at least in part, on how you asked your question. I would have great difficulty in giving you a correct and understandable answer.

These are not things that can be explained in ordinary language. Those who tell you the opposite may not have understood each other - they will certainly leave you deeply misunderstood.

I offer you an old quote:

"Philosophy [ie physics] is written in this great book - I mean the universe - that is always open to our gaze, but it cannot be understood unless you first learn to understand the language and interpret the signs in It is written in the language of mathematics, and its signs are triangles, circles and other geometrical figures without which it is humanly impossible to understand a single word, without which one wanders around in a dark labyrinth. "

Galileo Galilei, Il Saggiatore (The Examiner, 1623).


Hello Elio, I totally agree. Nature and its laws are by definition mathematical and immutable. However, I am not a mathematician, just an engineer. I think visually, so I need to use thought experiments to visualize the problem and use my intuitive understanding of math (calculus, vectors, and tensors) to see if the visualization works. I hope to get a mathematician or scientist to test my experiments. Thanks for your contribution.

Nigel Colebrook

All matter moves through space-time. The larger the mass, the slower the time appears. All matter moves from where time is fastest to where time is slowest, where time is slowest or stops completely. This is evidenced by a "black hole". Faults occur due to the interaction of matter with space-time. Gravity is simply a matter of moving to where time is slowest.


Hello Nigel, a novel analogy that fits the law of gravitation. Understanding why or how matter interacts with space-time in order to distort it led me to the opening post. Many Thanks.