Big bang just two rocks colliding. Maybr just a side glace why diffrent rotashion

a reply to: Leto2

I'm not trying to be rude but faster than light speed is impossible, in nature, as far as I've read. (the subject is very interesting and the link is great and informative)

Yes, you are right. An object with mass cannot travel faster than light. The 'speed of light' is a maximum speed limit for matter. Note however that light does move at different speeds influenced by the medium they are traveling through (including gravitational fields), and different wavelengths are affected by this medium differently. This is demonstrated by the bending of light in a prism as explained by Newton, or by the gravitational field of the sun as explained by Einstein. This 'gravitational lensing' effect is currently the most powerful tool we have in exploring the farther reaches of the universe, and indeed proves the existence of 'Dark Matter' (though the precise nature of Dark Matter is still an open question).

However, remember that light is moving within spacetime. What happens if spacetime itself is expanding?

Thought experiment:

1) You have a balloon (this is a standard mind model of the expanding universe - the universe is not a balloon, this is a mind model only). The balloon is inflated to about the size of a volleyball and since it is a mind model, we are going to imagine that it can expand forever.

2) There are two dots on the balloon about 5 centimeters apart.

3) On one dot we place an ant that we have somehow imprinted an infallible desire to 'run' straight for a piece of its favorite food at its maximum speed of 1 centimeter per second.

4) On the second dot we place a bit of the ant's favorite food.

What will happen? The ant should charge that piece of food and get to it in exactly 5 seconds - right?

Ok what happens if we start blowing air into the balloon - the balloon starts to expand and the dots start moving away from each other.

Lets say we do it slowly at first, in such a way that the dots move away from each other at 1 centimeter per hour. So the ant will take a little longer than 5 seconds to reach the food, because by the time it has been traveling for 5 seconds the dot is ever so little bit farther away.

Suppose we fill it faster, so that the dots move away from each other at 5 millimeters per second (half the speed of ant). So now, when the ant has traveled for 5 seconds, the food is still 2.5 centimeters away; so he goes for another 2.5 seconds and the food has now moved a further 125 millimeters, and so on. Of course eventually, the ant will reach his goal (Zeno's paradox notwithstanding), but it has taken much longer to reach because the goal is moving away (sounds like a conspiracy theory or something almost).

OK, now lets fill the balloon even faster, lets fill it so that the dots are moving apart faster than the speed of ant. Now the ant can never reach the food.

This is the fate of the universe. It is expanding, we know that, but even more interesting is that the expansion is accelerating. Eventually objects will be moving apart faster than light and the sky will start to go dark as objects move beyond the 'horizon'.

What is causing this acceleration is one of the great problems in cosmology and physics today. It must be some kind of energy (or gravity) that we have no experience of, so scientists call it 'Dark Energy'. Again, the term 'Dark Energy' is not a term that actually describes the 'energy', its 'dark' because we don't know anything about it. Much the same way that Medieval Europe is informally known as the 'Dark Ages' - those years weren't really dark, we were just unfamiliar with them because they were poorly documented (at the time the term was coined).

In fact, 'Dark Energy' might not actually be a new kind of 'energy', it might turn out to be a new kind of 'gravity'. We don't really know which side of Einstein's Field Equation will need to be adjusted yet. This is the equation that describes the equivalence between matter and gravity (or geometry since gravity is described as the geometry of spacetime - you've seen the mind model of spacetime as a giant rubber sheet with masses making 'dents' in the sheet).

Either way, if and when it is all figured out, the physics involved will be at least as much of an advance over Einstein as Einstein was over Newton.