Expanding universe

  • Thread starter Swimfit
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  • #26
Drakkith
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The only way I can describe it, is that the universe is expanding and it does not require that it be expanding INTO anything. That may not make sense to you, but it's the best way of putting it as far as I know.
 
  • #27
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Instead of thinking of the universe as 'expanding', (which does seem to imply movement), think of it as there 'being more space'.
 
  • #28
There really should be a better term to disambiguate.

Space within the known universe, our universe, is expanding. Not the universe. By very definition, nobody knows what is beyond the known universe.

When most people think of the universe, they are imagining all of existence, not just what we know.
 
  • #29
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I just wrote this message and it didn't post ugggg! What I meant when I said our space time I meant our known universe. So it is acquiring more space and yet not growing or getting more volume, or it is, but not moving into anything thing. I believe what you are telling me. I'm trying to put it into words that I understand and so you all will say now you got it! Lol
 
  • #30
Drakkith
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The universe is expanding and increasing in volume, yet this does not *require* that there be anything for it to expand into. Whether it is or isn't is not knowable currently. We have no idea if it is actually expanding into more space, inside a 4th dimension, or whatever. Our models simply say that these things are not required in order for the universe to expand.
 
  • #31
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Thank you for taking all the time helping me too understand about the expansion. I was watching some videos on YouTube about the expansion of the universe. It was very interesting. It was saying that the outer most stars that are in the red shift that space around them could reach faster than the speed of light, and that they could soon get past the point of us being able to see them anymore. Are they too reach those speeds because of less gravity? Swimfit
 
  • #32
phinds
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Thank you for taking all the time helping me too understand about the expansion. I was watching some videos on YouTube about the expansion of the universe. It was very interesting. It was saying that the outer most stars that are in the red shift that space around them could reach faster than the speed of light, and that they could soon get past the point of us being able to see them anymore. Are they too reach those speeds because of less gravity? Swimfit
The "outermost stars" in the OBSERVABLE UNIVERSE are moving away from us at 3 times the speed of light because of the not-understood phenomonon we call "dark energy", which seems to be the same thing as the "cosmological constant" which causes the DIMENTIONS between not-gravitationally-bound systems to increase, and to increase more the farther apart they are.
 
  • #33
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After I sent that last message the thought came to me dark energy. It's funny I always thought that nothing could travel faster than the speed of light. But that rule pertains to massive objects and space has no mass, so can go as fast it wants. Now does dark matter have mass? Or is that an unknown, or unmeasurable? God all this stuff fascinates me. Swimfit
 
  • #34
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After I sent that last message the thought came to me dark energy. It's funny I always thought that nothing could travel faster than the speed of light. But that rule pertains to massive objects and space has no mass, so can go as fast it wants. Now does dark matter have mass? Or is that an unknown, or unmeasurable? God all this stuff fascinates me. Swimfit
Since dark matter is known exclusively through it's gravitational effects, and since gravitation implies the existence of mass, I'd guess that it does indeed have mass. But if it's a kind of mass which does not interact electromagnetically with ordinary mass, we'd have no way of detecting it other than gravitational effects.
 

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