Hypothetically, if space could be moved or scaled, what would happen to everything inside?

I'd like to know if an element of momentum could be transferred to objects by contorting space-time.

Other than gravity, what effects does space-time contortion have on mass?

  • $\begingroup$ It seems that what astronomers call gravitational waves are more or less what you are referring to. If it is the case, then these waves have momentum, which they can transfer to objects. It is argued that it might be possible to detect them that way. $\endgroup$
    – chris
    Jun 3 '14 at 2:10
  • $\begingroup$ @proPhet, does chris's comment satisfy your question, or do you want a more detailed answer? $\endgroup$
    – HDE 226868
    Aug 13 '14 at 17:46
  • $\begingroup$ @Chris Care to make your comment an answer? $\endgroup$
    – HDE 226868
    Oct 2 '14 at 0:37
  • 2
    $\begingroup$ Reminds me of an article I read as an undergrad, which I have no hope of finding now. It included a graph of the average momentum of objects from planets up to galactic clusters, and speculated about extrapolating to the entire universe. Of course, we could never detect it from inside the universe, but a similar speculation was made for angular momentum. If the universe as a whole had angular momentum like virtually every object and collection of objects in the universe, could we detect it? How? $\endgroup$
    – Marc
    Oct 2 '14 at 3:55
  • $\begingroup$ @Marc Seen this question (astronomy.stackexchange.com/questions/6493/…)? Unfortunately, the OP's self-answer was deleted because it was low-quality, but it explained more the "spinning universe" idea. The difference between him and you is that you did not assume the idea was correct. Have you considered posting this as a question? $\endgroup$
    – HDE 226868
    Oct 2 '14 at 15:08

I'm going to build off of chris's original comment. I haven't had a response from him during the 24 hours since I asked the question, and there doesn't appear to have been any activity from him recently (Note: don't confuse him with another user who goes by Chris), so I might as well expand upon what he said.

Gravitational waves do appear to be what you're looking for. They are emitted by systems with varying quadrupole moments (see https://en.wikipedia.org/wiki/Gravitational_wave and https://en.wikipedia.org/wiki/Quadrupole for more information); commonly cited examples are binary neutron stars. In fact, one such binary, the Hulse-Taylor binary, was the first discovered system to emit gravitational waves.

Gravitational waves carry energy away from the system, at a rate of $$\frac{dE}{dt}=-\frac{32}{5}\frac{G^4}{c^5}\frac{(m_1m_2)^2(m_1+m_2)}{r^5}$$ where $E$ is eneryg, $t$ is time, $m_1$ and $m_2$ are the masses of the objects in the system, $r$ is the distance between them, and $G$ and $c$ are the constants, the universal gravitational constant and the speed of light. I invite you to do the calculations for a given system, if you please. I can assure you that it's one of the easier calculations in general relativity! This release of energy causes the orbits of the two neutron stars to gradually decay, and it is thought that eventually the two will merge.

The answer boils down to this: Yes, gravitational waves can carry [angular] momentum, just like many other types of waves. They also have frequency, amplitude, wavelength, and speed, just like the "normal" waves we are familiar with.

I hope this helps.


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