Is the universe expanding?

Question

How do you know? What difference does it make?

What a completely bullsh*t answer legsology. Nothing further to back it up? "Matter expands"? Really? WWWWHY? Gravity is alway attractive....
Matter on earth doesn't "always" expand".

The universe is expanding because....who discovered this?

ding ding ding! Fen is the best answer yet...BUt WHO discovered the red shift?

Answer 1

Is the universe expanding? Evidence points to the answer being - Yes.

Edwin Hubble discovered this with the observation that the extent of red shifting of light increases with distance.

In fact, its recently been discovered, but still argued that the rate of expansion is not decreasing, but increasing leading to ideas that there may be some sort of anti-gravitational force at work. Something that at extreme scale causes matter to repel itself rather than attract as it does on conventional scales.

This may be, in theory, evidence of the idea that gravity is indeed a force in the classical sense, mediated by a particle that has a opposite rather than how general relativity describing gravity as a consequence of the presence of matter producing warps in space-time.

Edit - Fen - you are correct, but have swapped the terms. Red shift happens when wavelength is elongated due to the source moving away from the receiver. Blue shift is the reverse where the wavelength is shorted due to the source moving closer to the receiver.

Answer 2

The universe is expanding. We know this because of how light changes when it's source is moving towards or away from us (sort of like a Doppler effect with sound waves). We know some galaxies move towards us because their light gets shifted into a shorter wavelength (a "redshift"). On the other hand, galaxies moving away will have an elongation of wavelength (a "blue shift"). The motion of these galaxies towards and away from us shows that the universe is expanding. This is important because the entire universe was once a singularity (a point with 0 volume and infinite mass). We then had the "Big Bang" and all the matter in that singularity started flying apart. The expansion of the universe is a representation of this original force that lead to the current universe.

Answer 3

The concept of an expanding universe has been around for awhile -- Vesto Slipher is credited as first to discover this with his observation of the red shift in other galaxies in 1912, and later Hubble and others became more thoroughly involved with measuring the red shift on other galaxies.

But a recent significant development occurred in 2000, with Srianand, Petitjean, and Ledoux's research into the red shift, which was published in Nature and provided more empirical evidence. This study can be read here: http://arxiv.org/abs/astro-ph/0012222
A discussion of this study and its implications can be found here: http://www.eso.org/outreach/press-rel/pr-2000/pr-27-00.html

You can also view results from some other studies under the "Observational Evidence" section of this article at Wikipedia: http://en.wikipedia.org/wiki/Expanding_universe

It not only appears that the universe is expanding, but that it may be expanding at an increasing rate. To my knowledge, the mechanism behind this increasing rate is not fully understood.

Hope this helps you.

Answer 4

Yes it is. Because of the "Big Bang", the universe exploded radially outwards, increasing in size. It doesn't really make much difference, because the universe is for all sakes and purposes, infinite.

Answer 5

as far as im concerned the universe is the area that humans can reach, comprehend, or mathematically prove the existene of. Noone has ever convinved me of an "edge" of the universe.
anyway so far my universe has consisted of north america. For all i know china could be fake :o

Answer 6

Universe is made of matter. Matter expands.

Answer 7

according to several scientists, the universe is actually contracting because of a vacuum