How did it come to be there are different races of people

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As I meantioned, I’m not an atheist, just cursed with the ability to spot a bad argument.
 
So anything a rabbi puts out is propaganda but if a Catholic does so it’s not? Haha, what kind of a joke is this!
 
buffalo said:
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niceatheist:
a personal conclusion that such a being is probably not necessary,
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In other words an uncaused cause is not necessary to start things rolling?
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Sorry for replying so late. Been a busy week!

That’s one way to put it, I suppose. But I usually invoke the notion of a compact manifold. In effect, a compact manifold is a finite space that has no boundary. If you think of a circle, for instance, that’s an example, in one dimension, of a compact manifold.

If we look at space-time, we could describe it as a 4-th dimensional compact manifold. Here’s the critical point, if we consider time as a dimension, in this model, time is finite, but it has no defined beginning. There isn’t a point where time starts. Think of time as a curve, as you go back in time, the curve grows steeper, but you never reach Time 0. A useful analogy is trying to accelerate to the speed of light. Anything with mass can never accelerate to the speed of light, the closer such an object gets, the greater the energy requirements to move a little faster, until finally it takes an infinite amount of energy to reach the speed of light. That’s a curve that has a finite limit, but as you travel on that curve, you can never actually reach that limit.

If we think in terms of four-dimensional space-time, it means that the universe is finite in time and space, but if you could go back in time, you would never hit the initial event. That’s what the notion of imaginary time is (and no, that doesn’t mean it’s made up, it’s based upon the mathematical notion of imaginary numbers).

Let’s remember here, that both Big Bang cosmology, and the more modern Inflationary model, don’t set out to explain how the universe began. Big Bang cosmology at its core simply says “the universe was once extremely (perhaps infinitely) hot and dense, and then began to expand and cool”. The theory says nothing about where the universe came from, and in the model I’m describing, there is no “came from”. The universe may be a finite structure, but it has no defined starting point, either in time and space.

Now, of course, I’m not saying that’s a scientific hypothesis. It may be a mathematically-supportable model, but since we’re talking about a region of time-space that, at least by any technology we have now, we can never hope to probe, it remains a model that may or may not have anything at all to do with the actual universe. Aristotle and his intellectual descendants could be quite right about a Prime Mover. All I’m trying to say is that I think I have a rational model for the Universe’s origins, not that I know the truth.
 
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The Borde Guth Vilenkin Theorem states there is a beginning.

Physicist Dr. Alexander Vilenkin explains his theorem (the Borde Guth Vilenkin Theorem or the Kinematic Incompleteness Theorem) in simple terms that if you have a Hubble expansion that has an average greater than zero, then the universe pretty much has a beginning. Also, Vilenkin answers some critics of his theorem.

 
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buffalo said:
You disagree with the theorem? Why?
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Because the theorem, which in part seems misrepresented by some Creationists/IDers, explains only a certain subset of possible models, and in no way is a meaningful critique of Hawking’s hypothesis (which is the one I have badly paraphrased).
 
buffalo said:
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niceatheist:
xplains only a certain subset of possible models,
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And the other models that you think are more powerful are?
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I’m not in a position to assess them in any depth, and I stated above, I’m not attempting to justify my view scientifically. All these models, whatever their merits, are essentially mathematical constructions that may or may not describe reality in whole or in part. My point was that I hold that my view on the origins of the universe is rational, in that is based on internally-consistent models.
 
Finally, I would like to discuss the central topic of this session, the question of whether or not the universe had a beginning.

The name eternal inflation, as I pointed out earlier, could be phrased more accurately as future-eternal inflation . Everything that has been said so far implies only that inflation, once started, continues indefinitely into the future. It is more difficult to determine what can be said about the distant past.

For the explicit constructions of eternally inflating models, the answer is clear. Such models start with a state in which there are no pocket universes at all, just pure repulsive-gravity material filling space. So there is definitely a beginning to the models that we know how to construct.

In 1993 Borde and Vilenkin proved a theorem which showed under fairly plausible assumptions that every eternally inflating model would have to start with an initial singularity , and hence must have a beginning. In 1997, however, they noted that one of their assumed conditions, although valid at the classical level, was violated by quantum fluctuations that could be significant in eternally inflating models. They concluded that their earlier proof would not apply to such cases, so the door was open for the construction of models without a beginning. They noted, however, that no such models had been found.

At the present time, I think it is fair to say that it is an open question whether or not eternally inflating universes can avoid having a beginning. In my own opinion, it looks like eternally inflating models necessarily have a beginning. I believe this for two reasons. The first is the fact that, as hard as physicists have worked to try to construct an alternative, so far all the models that we construct have a beginning; they are eternal into the future, but not into the past. The second reason is that the technical assumption questioned in the 1997 Borde-Vilenkin paper does not seem important enough to me to change the conclusion, even though it does undercut the proof. Specifically, we could imagine approximating the laws of physics in a way that would make them consistent with the assumptions of the earlier Borde-Vilenkin paper, and eternally inflating models would still exist. Although those modifications would be unrealistic, they would not drastically change the behavior of eternally inflating models, so it seems unlikely that they would change the answer to the question of whether these models require a beginning.

So, as is often the case when one attempts to discuss scientifically a deep question, the answer is inconclusive. It looks to me that probably the universe had a beginning, but I would not want to place a large bet on the issue.
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~Alan Guth
 
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