speed of the expantion of the universe?

Question

I know its supposed to be faster than light. But how can we tell its faster than light if our only way to tell how fast its moving away is how light reaches us? Is it the change in the red light? If this doesnt make sense im sorry i very drunk right now.

If that first answer has merrit, does that mean that in a sense more matter is created constantly. And by matter i mean space/time which of course has no matter its just easier to wrap my mind around it that way. In essence if you had a piece of paper with two dots on it more paper in between the dots would be generated right? If so how, why, and why is that more logical than them expanding?

Answer 1

The expansion of the universe causes distant galaxies to recede from us faster than the speed of light, if Comoving distance and cosmological time are used to calculate the speeds of these galaxies. However, in general relativity, velocity is a local notion, so velocity calculated using comoving coordinates does not have any simple relation to velocity calculated locally. In other words, the galaxies (or more accurately, galaxy clusters) do not physically move away from each other. Rather, the fabric of spacetime between them expands. This also explains the Inflationary epoch during the Big Bang, when the universe expanded from a size a hundred billion times smaller than a proton to approximately one hundred million light years in diameter in just 10-32 of a second.

Answer 2

The expansion of the Universe cannot be faster than the speed of light because there is the mass of the galaxies that are expanding outward and according to Einstein it would take an "infinite" amount of energy to accelerate mass even just to the speed of light. That's ok that you are drunk. I will try to explain this in simple terms. There is something that Sir Edwin Hubble came up with and that is the amount of red-shift that a far away object like a galaxy would have. Hubble said that the further the galaxy is away from us then the greater the redshift. At the furthest galaxy the redshift is almost equal to the speed of light.

Answer 3

I am not sure what you mean by "more logical". It just is the best way to explain the observations. The fact is, more stuff keeps appearing over the horizon (the distance light can travel since inflation dragged stuff over our horizon in the first place). Here is how we arrive at this somewhat startling conclusion:

1) The red shift implies expansion.

2) The uniformity of the temperature of the early universe in opposite directions implies that those two bits of the universe used to be in thermal contact via radiation, diffusion or whatever. Regardless, they were able to interact pretty well using mechanisms that operate at the speed of light or slower.

3) Those two chunks of the universe can no longer interact, because we are between them and it has taken essentially the entire age of the universe for their light to reach us at this point in between.

Put it all together and those bits were at one time within one anothers horizon and now they are not. Assuming we are not in any special part of the universe, it is safe to say there are parts of the unverse that were at one time within our horizon, but now are not.

One possibility to consider is that the universe is finite and "wraps around" rather like the screen in the video game "Asteroids". In this case, if it was expanding, we would still see redshifted light from early in the universe, but at the same time all the contents of the universe could be within our horizon.

I am confident that we could construct observations that could test this hypothesis, but I am unsure whether any currently existing observations or even observational programs, can test it.

Answer 4

Because the determination of its speed is based on the smart factor of the existence basically the universe is telling us there is something smarter than the speed of light more sensitive than light. That is a big deal. There was a person who levitated from the ground and whether it is common knowledge or not this person has the ability to free countries from war and anything in relation to war by receiving $10 billion.

Answer 5

you are right about that, the fact if if space is expanding it needs to be filled by something, that is where dark matter comes in, thought what we consider as physical matter is not being created to fill in those gaps, there is a theory of dark matter. It is actually well supported because it would account for the missing mass of the universe. It is a very complicated explanation to write, but if you look it up, it will answer your question

Answer 6

Deepak sounds like he's on the right track with this one. Just don't forget about how relative everything is, the light, the speeds of the objects, and our perspective on the whole thing.