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bigsplit
2004-Aug-11, 03:04 PM
In the last 7 years or so we have discovered that expansion is accelerating. Is this expansion accelerating at a constant rate? When will we have a new report on this? I think the acceleration will continue at an accelerating rate. What do others think?

Wally
2004-Aug-11, 03:31 PM
I think that the current belief is that the expansion is accelerating at an accelerating rate. The more space between galaxy A and B, the greater the acceleration. It's self-fullfilling. . .

milli360
2004-Aug-11, 03:43 PM
So, instead of the Big Bang, it should be the Big Jerk?

Ut
2004-Aug-11, 04:10 PM
Nu uh! You're a Big Jerk!

I'm still not quite buying the accelerating universe. It's too new for me to latch onto it. So, I'll wait to see if I get Big Ripped by the Big Jerk for a while longer...

bigsplit
2004-Aug-12, 12:15 PM
What mechanism of space pushes the galaxies apart?

eburacum45
2004-Aug-12, 01:07 PM
Try this article on 'Quintessence';
http://physicsweb.org/article/world/13/11/8


When the volume of the universe was 100 orders of magnitude smaller, say, the mass density was 100 orders of magnitude greater, but the vacuum energy density had to have the same value as today. In other words, the vacuum energy density remained constant as the universe expanded, but the total vacuum energy increased as the volume of space increased. This extra energy came from the gravitational potential energy of the universe. Whatever physical processes created the initial energy in the universe had to arrange for an exponentially large difference between the two forms of energy, but somehow this difference had to have exactly the right value for the vacuum energy to become important 15 billion years later.

bigsplit
2004-Aug-12, 01:22 PM
Try this article on 'Quintessence';
http://physicsweb.org/article/world/13/11/8


When the volume of the universe was 100 orders of magnitude smaller, say, the mass density was 100 orders of magnitude greater, but the vacuum energy density had to have the same value as today. In other words, the vacuum energy density remained constant as the universe expanded, but the total vacuum energy increased as the volume of space increased. This extra energy came from the gravitational potential energy of the universe. Whatever physical processes created the initial energy in the universe had to arrange for an exponentially large difference between the two forms of energy, but somehow this difference had to have exactly the right value for the vacuum energy to become important 15 billion years later.


I think I gotcha.

What would be wrong with saying that the Universe's Volume is constant and that before the Big Bang Mass density was homogenious. The mass density is increasing in magnitude, with the same amount of mass taking up less and less space. This would mean an increase in vacuum density.