ski233 t1_isk1bb0 wrote
Reply to comment by Morbos1000 in Do 2 objects on opposite "ends" of the universe pull on each other to some extremely minute degree? by Courcy6185
We don’t know this for certain that there are any parts of the universe expanding faster than the speed of light. That is just a theory.
BridgeOnColours t1_isk9dz3 wrote
However there's a force that makes light or electromagnetic wavelengths stretch which can't be explained by any other means but space expanding at a rate faster than light
ski233 t1_isk9jq8 wrote
Space is expanding. But not faster than light in any way/place we have observed.
BridgeOnColours t1_iskbwn9 wrote
The reason we need JWST instead of Hubble telescope to see extremely far objects is the reason why your statement is wrong
ski233 t1_iskc265 wrote
If the distant objects were expanding away from us faster than the speed of light then we wouldnt be able to observe them.
BridgeOnColours t1_iskcrcu wrote
But we are able to observe them, because JWST is able to picture objects which wavelengths have been stretched into the infrared wavelengths, making it unobservable to Hubble, which can mostly detect visible light and some UV light.
[deleted] t1_isku2nk wrote
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Ape_Togetha_Strong t1_islj6l3 wrote
We cannot observe things that are expanding away from us faster than the speed of light.
We can only observe the past of objects that are currently expanding away from us faster than light, because the evidence of that past was emitted before the object was expanding away faster than light.
That is the light that is highly red-shifted.
MisterET t1_islgwk5 wrote
That's exactly true! That's called the observable universe, which is smaller than the actual universe. Our observable universe is expanding at the speed of light, but objects already outside of that bubble will NEVER be inside that bubble. They are forever outside our observable universe.
MisterET t1_islgnlf wrote
Think about the implications of what you just said though. If space is expanding, and space is also very, very large, then there exists two points so far apart that they are expanding away from each other faster than the speed of light.
You don't even need to observe it specifically. If space is in fact expanding, that expansion is cumulative, and it necessarily exceeds c once you get enough space between points.
Ape_Togetha_Strong t1_iska6mb wrote
The majority of the observable universe is expanding away from us faster than C. The distance at which the expansion is faster than C is only around 14.5 billion lightyears, and the radius of the observable universe is ~46billion.
Jamandi_Aldori t1_iskmhhy wrote
>We don’t know this for certain that there are any parts of the universe expanding faster than the speed of light.
The statement he made does not require the universe to be expanding faster than light. Just expanding faster than the rate of acceleration that the gravitational influence of distant objects would have.
We know this it to be true, objectively, because we can measure and observe the relativistic red-shift of distance galaxies as they move away from us at various fractions of the speed of light.
ski233 t1_isksz60 wrote
What he said was “faster then causality” ie the speed of light.
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