posted on Jul, 7 2005 @ 12:47 PM
We've long known that the universe is expanding.
There's something called "Redshifting" and another thing called "Blue#ing" - they are consequences of the fact that light has a constant speed
and frequency. When you change the frequency (by moving something towards you as it transmits light) the wavelength must change, and different
wavelengths produce different colours of light.
There is a common misconception that matter all sat at a specific point in the universe and then an explosion happened and then the matter was flung
outwards, which is why it's "expanding" right now. This isn't quite realistic.
The reality (as we know it) is that the universe itself was a single point, and some event caused a massive rapid expansion of the size of the
universe itself, allowing the trapped matter to expand. The expansion was more rapid than an explosion and took place at or near the speed of light
(there is also some theoretical supposition that expansion faster than light occured, but I won't go into it here.) - The universe continued to
expand along with the matter in it. But it's not just like a bubble getting bigger with air filling it up.
Space itself is expanding, the distance between you and your computer is actually getting larger. The distance between the sun and the earth is
increasing, and so is the distance between the Milky Way and Andromeda. Usually though, it's just such a TINY TINY amount, that it's undetectable.
For you to notice a difference in the distance between you and your computer you'd have to sit perfectly still for millions of years, and even then
it would be only microns of distance. But, on large scales, between galaxies, there is enough expanding space there that the difference is
Thus, we look out and see a galaxy giving off more red light than blue, and know it is moving away, because its wavelength has become longer, meaning
its frequency has decreased, and speed is maintained.
(By the way, the equation for this is v=fL - speed =frequency*Lambda, which is Wavelength.)
Blueshifting occurs when galaxies move towards us faster than space between us is expanding, and it does happen.
Not to be mistaken again though - galaxies are literally moving through space the way we commonly think, but spacial expansion is the key factor in
our knowledge that most of them are moving away.
And, it's expected that there is a force such as anti-gravity or a massive amount of gravity pulling outwards that is causing this expansion, It's
one of the "great questions" that we don't really have an answer to.
And, please, before someone asks "Well what was there before the universe?" - I'd like to remind you that it does not make you look smarter, but
stupider. It's a hole in the theory, and everyone is well aware of that thanks. Religion doesn't do any better except just say "Oh, god did it. He
can, cause he's god." - so let's skip the whole thing as it's counterproductive and useless. No one has the right answer for what came before the
universe, but science is trying to describe what happened after.
Oh, tag on to the post: The chances it's a force that we haven't discovered are very slim - it is likely a property of a force we currently know, or
it is one of the combined forces. It is known that the Weak Nuclear and Electromagnetic forces combine at high energies, and that at higher energies,
so does the Strong Nuclear force. It's expected that somewhere, gravity does too. Most people think it's at a very high energy that we can't hope
to reach for a long time, some think it's a very very low energy. No answers here yet, either. But it is thought that expansion may be caused by the
unified force of all of them combined.