Eternal and Infinite Physical existence?

[seer]

I understand that you believe in God and that he created the universe out of nothing, and of course since we can't say for sure, being that we do not know the answer to this question, at least not as of yet, it is a possibility, but it is also possible that that which is, i.e., the natural world, is eternal and that the universe, our universe, is a part of that eternal existence. We do know of possibilities as to how our universe came to be which does not contradict the natural law of cause and effect, what we don't know of is why, as Liebniz put, there is something rather than nothing, and that question would would need be answered whether it were asked of God or of the universe.

Jim, that is the problem even if we found a cause for the effect of this universe. How could one ever show whether that cause was eternal or not. I don't see how science could ever answer the question. It will remain a question of faith.

[Leonhard]

I don't see how science could ever answer the question. It will remain a question of faith.

You believe that if something isn't Science, then its pure faith?

[JimL]

Jim, that is the problem even if we found a cause for the effect of this universe. How could one ever show whether that cause was eternal or not. I don't see how science could ever answer the question. It will remain a question of faith.

Because we can not see how science can or will answer this question does not mean that it can not answer it, and until then it will remain a question of faith, and or a matter of belief, but I don't see reason to abandon science and natural law in this quest, and jumping to a supernatural conclusion just because the answer is difficult to see or explain. The universe may have been created, or it may itself be eternal, but being that we are imperfect beings ourselves, I don't fear that a perfect being would hold our beliefs about it against us.

[seer]

You believe that if something isn't Science, then its pure faith?

Nope...

[Leonhard]

Nope...

Uh huh?

[seer]

Because we can not see how science can or will answer this question does not mean that it can not answer it, and until then it will remain a question of faith, and or a matter of belief, but I don't see reason to abandon science and natural law in this quest, and jumping to a supernatural conclusion just because the answer is difficult to see or explain. The universe may have been created, or it may itself be eternal, but being that we are imperfect beings ourselves, I don't fear that a perfect being would hold our beliefs about it against us.

Well, what a Perfect Being would or would not hold against us is up for debate. My point is that we could never know if matter/energy are eternal into the past. Not even in principle.

[seer]

Uh huh?

Uh huh? What?

[Leonhard]

Uh huh? What?

Just wished you had qualified your response a little more like I'm gonna do now with mine; You said that Science couldn't answer the question. And the implication seemed to be that therefore it would be a faith issue.

[Leonhard]

Lumps in the intertubes.. made me double post accidentally.

[Leonhard]

Well, what a Perfect Being would or would not hold against us is up for debate. My point is that we could never know if matter/energy are eternal into the past. Not even in principle.

Very, very, very, very, very, very few things are such that we can know them absolutely. You can't know that there is a computer in front of you with complete certainty. Even in principle. Saying that we'd have to have complete empirical verification of the universe being infinite in size (either spatially and/or temporally) before we could say that we know is special pleading. You wouldn't call for this level of confirmation in general. The evidence so far confirms that the universe has an average energy density of zero, this is consistent with the hypothesis that it is zero (which predicts that this is what we'll find in all future measurements). If the average energy density is zero then the result in an infinitely large universe, even if it would only be of a finite age.

[JimL]

The evidence so far confirms that the universe has an average energy density of zero, this is consistent with the hypothesis that it is zero (which predicts that this is what we'll find in all future measurements). If the average energy density is zero then the result in an infinitely large universe, even if it would only be of a finite age.

Leonard, I wonder if you could explain for me exactly what this means? What does zero energy mean? Does it mean that at a fundamental level energy doesn't exist or what?

[Leonhard]

Leonard, I wonder if you could explain for me exactly what this means? What does zero energy mean? Does it mean that at a fundamental level energy doesn't exist or what?

Zero energy density, that's different. See the curvature of spacetime is determined uniquely by the amount of energy and momentum in any given point of space. Cosmologists are only interested in the large scale structure of spacetime, thanfully it seems we live in a simple arranged universe (otherwise the equations have proven intractable), on sufficiently large scales the universe homogenous and isotropic (a completely unbiased random placement of matter in a universe will behave like this, so maybe its not so suprising). The large scale structure of space time is then determined by the average energy density of the universe. Fields and matter contain energy. It seems so far that observations back up the hypothesis that the energy contained in the mass in this universe is exactly balanced by the energy contained in the fields. So on average there's zero energy density in this universe. If that's the case then Einsteins equation for spacetime solve beautifully into a spatially flat (on large scales away from gravity wells) space time. And such a spacetime is infinitely large.

[Leonhard]

Tweb is acting funny, double post again.

[JimL]

Zero energy density, that's different. See the curvature of spacetime is determined uniquely by the amount of energy and momentum in any given point of space. Cosmologists are only interested in the large scale structure of spacetime, thanfully it seems we live in a simple arranged universe (otherwise the equations have proven intractable), on sufficiently large scales the universe homogenous and isotropic (a completely unbiased random placement of matter in a universe will behave like this, so maybe its not so suprising). The large scale structure of space time is then determined by the average energy density of the universe. Fields and matter contain energy. It seems so far that observations back up the hypothesis that the energy contained in the mass in this universe is exactly balanced by the energy contained in the fields. So on average there's zero energy density in this universe. If that's the case then Einsteins equation for spacetime solve beautifully into a spatially flat (on large scales away from gravity wells) space time. And such a spacetime is infinitely large.

Okay, I'm not sure that I get it, but perhaps do you mean by this that the energy balance between that contained in matter and that contained in fields is equal to the potential energy contained in a false vacuum from out of which the universe began, whatever that value was?

[magellan004]

Actually, quantum theory is much more fashionable, as people try to develop a particle theory of gravity that could also encompass Einstein's theory. Einstein's theory seems easier conceptually so I am more familiar with it, but only as a layman. Surely, you do not mean to seriously imply that Einstein's theory should not be employed by cosmologists and other scientists, do you?

From what I can gather- Einstein's equations are useless. People pay lip-service to them and ignore them. e=mc^2 is a classic example. Everyone knows it, no one uses it. No one can use it. So it's not a question of whether cosmologists should use Einstein to achieve anything. The reality is they don't. (But they say they do.)

Magellan