Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Christian.Muys on 14/12/2006 21:32:17

Title: Dark Energy - Speed of light
Post by: Christian.Muys on 14/12/2006 21:32:17

I have some remarks and associated questions,  regarding the lately often discussed 'Dark Energy'. There seems to be a consensus among scientists that the universe is expanding since the beginning, and recently one assumes the expanding keeps accelerating. The reason therefore is still a mystery and is generally named 'Dark Energy'. If however, all matter (stars, planets, ...) is accelerating for billions of years, then it's inevitable that matter reaches one day or another, the speed of light, and I would suppose that then the matter transforms into energy. I wonder if someone could say when exactly the farthest matter will reach that speed, what the consequences would be if massive planets and huge stars transform into energy, and if such process wouldn't contribute to even more accelerated expansion ?

I do hope one can forgive my not so proper English, as it is my fourth language.

Title: Re: Dark Energy - Speed of light
Post by: harryneild on 14/12/2006 23:34:04

Hmmmm. Im not sure that it is mass that is accelerating. Since acceleration is the change in velocity THROUGH space, the matter isn't accelerating, only the space between particles is becoming greater at an ever-increasing rate. Also, when the universe was born, it was expanding at far faster than the speed of light. In the first 10^-6 seconds the ‘singularity’ became as big as a solar system.

Title: Re: Dark Energy - Speed of light
Post by: ukmicky on 14/12/2006 23:58:13

Dark energy isn't pushing on the planets moving them away from each other its pushing on and expanding the fabric of space in between the galaxy clusters which the planets and stars reside.

Apart from local effects the only movement and speed a galaxy and everything within it experiences is the local movement in relation to the other galaxies local to itself . Relativistically wise each individual galaxy cluster is standing still and all the other clusters are the one,s doing the moving.

Could be wrong

Title: Re: Dark Energy - Speed of light
Post by: Dr. Praetoria on 15/12/2006 21:21:24

If dark energy is a type of fifth "force" that is opposing to the gravity force (pushes objects apart, increasing with distance} than what kind of space-time geometry do we have--negative? [???]
Doc

"A child of five would understand this. Send someone to fetch a child of five."
          ---Groucho Marx

Title: Re: Dark Energy - Speed of light
Post by: syhprum on 15/12/2006 22:06:25

In popular expositions it is often said that the universe started of the size of a pineapple, is there any particular reason for choosing that size?

Title: Re: Dark Energy - Speed of light
Post by: Christian.Muys on 15/12/2006 22:24:02

Quote from: ukmicky on 14/12/2006 23:58:13

Dark energy isn't pushing on the planets moving them away from each other its pushing on and expanding the fabric of space in between the galaxy clusters which the planets and stars reside.

Apart from local effects the only movement and speed a galaxy and everything within it experiences is the local movement in relation to the other galaxies local to itself . Relativistically wise each individual galaxy cluster is standing still and all the other clusters are the one,s doing the moving.

Could be wrong

Yes, I know allready it's very unpopular to even think of an explanation with existing theories. As long as in our own solarsystem, no one would doubt what would cause a varying distance between two moving objects, but once farther in space, it HAS to be something extraordinarily. It WILL be most likely extraordinarily, but to me, magically stretching spaces are as weird as supposing there are forces accelerating any mass.