GR: Why does space HAVE to contract in a gravitational well?

In summary, the speaker has been exploring the concept of general relativity without using tensor calculus and has successfully derived the same results as those using tensor calculus. They have also created a simulator to better understand the paradoxes of general relativity. The speaker has thought of an example for predicting and calculating time dilation in a gravitational well using the equations E=mc^2 and E=hv. They then ask if there is a similar intuitive example for why space has to contract in a gravitational field. The speaker mentions their progress on the concept of time dilation and questions the existence of "absolute time."
  • #1
dsoodak
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I've been playing with the idea of seeing how far I can get with general relativity without resorting to the learning of tensor calculus (at one point I decided I wouldn't believe SR until I derived it myself. I did (didn't need much more than 8th grade algebra), came up with the same results, and then made a simple simulator to understand the "paradoxes").

I've already thought of an example for predicting & calculating time dilation in a gravitational well:

If you assume that E=mc^2 and E=hv (both experimentally verified many times over), then photons have to lose a precise amount of energy (and thus frequency since E=hv) when going up out of a gravitational well or conservation of energy would be violated if you were to convert them into regular matter (since E=mc^2 and mass has more potential energy if higher up). Since the frequency of radio waves is related directly to the speed of the clocks in the circuit that generates them, time must move slower by the same amount.

Can anyone think of (or know of) a similarly intuitive example for why space has to contract in a gravitational field?

The only headway I've made so far is that the case where one of the observers is floating in a spherical shell (instead of standing on a planet's surface) makes it clear that the contraction would have to be equal in all directions (as opposed to SR where it is just in the direction of travel) and wouldn't be related to gravitational or tidal "forces" on the observer's atomic or molecular structure.

Thanks!

Dustin Soodak
 
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  • #2
Well, you might start off by thinking more about time dilation. Do you have the idea that there is some sort of "absolute time" that time dilates relative to? Or do you have something else in mind,,.
 

1. Why does space contract in a gravitational well?

Space contracts in a gravitational well because of the influence of gravity. As an object with mass, such as a planet or star, exerts its gravitational force, it causes space to curve and contract around it.

2. Can space expand in a gravitational well?

No, space cannot expand in a gravitational well. The force of gravity acts to pull objects towards each other, causing space to contract instead of expanding.

3. How is the curvature of space related to the contraction in a gravitational well?

The curvature of space is directly related to the contraction in a gravitational well. As objects with mass exert their gravitational force, they cause space to curve and become more contracted in their vicinity.

4. Is the contraction of space in a gravitational well uniform?

No, the contraction of space in a gravitational well is not uniform. It is stronger closer to the source of gravity and weaker farther away. This is due to the inverse square law, where the strength of gravity decreases with distance.

5. How does the contraction of space affect the passage of time?

The contraction of space in a gravitational well also affects the passage of time. This is known as gravitational time dilation, where time moves slower in a stronger gravitational field. This phenomenon has been proven through experiments and is a key concept in Einstein's theory of general relativity.

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