Shadowy Man

IntenSity:

I don't know what the universe was like before its hot and dense phase - like I said, I'm not up on my cosmological theory. However, there's pretty much incontrovertible evidence that it *was* hot and dense. I'm not personally convinced of anything more than that, like inflationary theory or the universe being a singularity, etc.

Black Moses posted:
Actually, they don't demand dark matter. There are some people working on alternate gravitational theories that may explain the "missing matter" problem.

atrahasis

Gravity might be as a result of space-time warping so i dont think any gravitational theory would would explain the "missing matter".

Again, does gravity have anything to do with matter?

I think the string theory is more close to this than any gravitational theory. The possibility of extra dimensions might in fact explain the "missing matter".

thank U

eh

You are mistaken here. When cosmologists say the universe may have been a result of a vacuum fluctuation, they are talking about the visible universe, or known universe. Our universe with galaxies, stars, people and art, may indeed have come about in such a way. But it would have done so in a pre-existing space, or some kind of super vacuum if you will.

Further, the virtual particles you talk about do not pop out of nothing. Empty space contains energy, and the fabric of spacetime itself. This is not a case of getting something from nothing.

Shadowy Man

Intensity:
Was there something before the big bang? I don't know. Could the current phase of the universe just be a parter of a large system? I would certainly think so.

My understanding of cosmology (and perhaps it just isn't complete enough) is that we can only obtain information as far back as the surface of last scattering. Anything that we think happened before then is based on theory, not observation. The extrapolation of the Hubble expansion back to a singularity is just that - an extrapolation.

Most physicists will even tell you that they think our current understanding of physics breaks down at the "earliest" times of the universe. So, in my opinion (for what it's worth) it is certainly possible that there was a "before the big bang". I need to study more on the inflationary model before I make a full decision about it. I heard Guth speak once about it and was a bit skeptical.

Shadowy Man

Black Moses:

Yes, I think the two are linked in some fundamental way. It's pretty obvious the way that we see things moving in space, especially when they move near massive objects, that gravitational forces and matter are related.

Synaesthesia

1. Everything that exists has a cause.
2. Everything that has a cause is contingent.
3. What is not contingent is necessary.
4. Nothing is non-contingent (1,2)
5. It is necessary that nothing exists. (3,4)
6. This argument does not exist.

Starboy

If nothing existed it would have to be called something.

Synaesthesia

Starboy,

The moment it's something, it ceaces to be nothing. So I just don't grant the validity of that move. Nothing comes from nothing, so something cannot come from nothing within the scope of my argument.

Ted Hoffman

Synaesthesia,
1. Everything that exists has a cause.
Do you have evidence for this? What caused the big bang?

This premise is flawed so your argument fails. Its an absolute statement from a temporal and limited being.
At best, its speculation.

Nothing does not exist.

Starboy

I acknowledge that you do not grant it, but it has been done before. It is called zero.

Starboy