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Author Topic:   Universe Race
Agobot
Member (Idle past 5645 days)
Posts: 786
Joined: 12-16-2007


Message 325 of 410 (459606)
03-08-2008 7:53 PM


And how come some of the experts speak with such great authority about the Big Bang, its phases, how it started, how it proceeded, how matter came to be, when, in fact, the Big bang itself is not proven to be a fact? It's just one of the proposed theories/albeit the best one, so far/. As time goes by, new theories will arise and replace older ones, as we gather more knowledge and evidence of the world. Sitting here explaining to others what happened at T=0, or close to it, is super silly, to say the least. We simply don't know and any attempt to explain it with our current knowldge base, in such great detail, is super funny and ridiculous. A lot of you guys got carried away in explaining the universe down to the last detail. Take a deep breath, relax and come back to reality. It's 2008, not 3008. We still don't have enough information about what you're discussing to make such bold statements, and it doesn't seem likely that it will change soon. In the meantime, it's not a shame to ask a question, it's a shame to pretend to know all the answers/even those concerning T~0/!
Edited by Agobot, : No reason given.
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Agobot
Member (Idle past 5645 days)
Posts: 786
Joined: 12-16-2007


Message 403 of 410 (460057)
03-12-2008 1:20 PM


quote:
In Summation...
The expansion of the Universe does not resemble the model in the OP in any way. While galaxies do move, that is not what is spoken of when referring to the expansion of the Universe. This makes the topic extremely difficult for many people to grasp - at the scale in which we live, such expansion is compeltely counterintuitive, and only Newtonian physics make instinctual sense to us.
But that doesn't mean it isn't happening. There is a mountain of evidence suggesting the Universe is expanding, from the redshift of galaxies to the cosmic microwave background. Every model that we run of the observed processes of the cosmos predicts that the Universe is expanding from a much hotter, much denser state. When we run models that start from such a state, we are able to make predictions that are then testable and verifiable - like the cosmic microwave background. The expansion fo the Universe from a much smaller, much more dense, much hotter state in the past is considered to be as rock-solid as the Theory of Gravity or other such virtually-proven models because of the shear weight of supporting evidence and verified predictions from the model.
Where we run into problems here is in the explanations to laypeople, particularly laypeople with no physics training whatsoever, and most especially with laypeople who have no physics education and have a predetermined cosmological view based on their religion.
The real meat of the Big Bang model can only be conveyed with mathematics - which would not be understood by any layperson (including me - it makes me want to go back to school again). We are left instead with using very imperfect analogies tro try to explain a very, very counterintuitive model to a layperson without the use of math - difficult even for a receptive student, and nearly impossible for someone who, at the core, wants to squeeze theology into the discussion.
The best analogy we were able to come up with is the globe analogy - the Universe simply exists (there isn't much of a "why" to science - until such time as we can examine the mechanism, if any, that resulted in the Universe existing, science will remain mute on the actual origin) and it posesses a particular 4-dimensional shape. We only really see three dimentions, because we perceive time only in a single direction (which is the real reason all of this is so counterintuitive).
Looking at the Universe from the outisde as a single 4-dimensional entity, you could say that it looks like the top half of a globe, with the dimension Time being represented by the North-South axis, and the three spacial dimensions being represented by the surface of the globe. T=0 would be the North Pole, and the surface "expands" as you move farther South. If you model matter in the Universe by pouring water over the globe, then as the water moves from T=0, the drops will move farther and farther apart as they move South - but this is not due to "real" motion with inertia and force the way objects react at smaller, in-Universe scales. Instead, the actual space between the matter (not the distance, but the space itself) is expanding, like the surface of a balloon. There isn't a "cause" for this expansion per se - the Universe simply has a certain shape, and our perception of that shape is dictated by our experience of time as a sequence of events in a single direction instead of being able to look from the outside. In this analogy, nothing needs to "start" the expansion - the universe only exists in a certain shape. Our experience of time is what gives us the concept of causality, and that's virtually thown aside when looking at time as just another dimension like length and width.
We know next to nothing about the exact moment where T=0. The mathematical models we currently use break down into a singularity at that point. Note that a singularity is not a physical object, nor is it a state of the Universe. The word "singularity" is used to denote a special case where our current mathematics simply don't work - that's all. It has nothing to do with "singular energy" liek what another poster keeps insisting, and neither is it necessary to "prove" that the Universe has a singularity at T=0. Such a statement wouldn't even make sense - by saying there is a singularty at T=0, all we are saying is that none of our math right now can tell us anything about T=0. All we know is that the spacial dimentions get smaller, the Universe becomes more dense, and it becomes hotter as you approach T=0 until the dimensions are so small, the Universe is so dense, and it is so hot that we no longer know how to model the conditions of the Universe, and we call this moment of uncertainty a singularity. It's just like a black hole - unlike what Star Trek would have you believe, there is no physical objectcalled a singularity in the center. Conditions inside of a black hole are so different from the rest of the Universe, and gravity becomes so incredibly strong, that our mathematical models stop working, and we call that uncertainty a singularity. A singularity is just a special case where we can't use any of our current models. Someday, hopefully, with additional research and new technologies, we'll be able to come up with a model that doesn't break down and that can give us additional information. Until that time, T=0 is a great unknown beyond the basic "it was really dense, it was really hot, and the spacial dimentions were tiny compared to today, or even compared to the size of a pea."
Some posters have latched onto the "pea sized Universe" and started syaing nonsense like "you say this pea sized universe existed and that it caused the universe we see today." Such statemnets show that they are missing the point - the pea-sized Unvierse is this Universe, simply at an earlier location in time. Such statements are like saying that "ice causes water." Ice is water, simply in a different state.
The expansion of the Universe is a fact. We can observe it in the redshift of galaxies, and every model we use featuring that expansion results in a Universe that looks just like ours. Extrapolating that expansion backwards through the process of logical inference, we predict that the Universe used to be smaller as you go backwards in time. Some will say that this is "not objective, empirical evidence," but the evidence it is based on IS. Logical inference is a perfectly rational method - it's what helps the police catch criminals from the evidence left at the crime scene, it's even what tells you that I exist even though you have never directly observed me. Logical inference told us there were additional planets in our Solar System - and when we looked where our models suggested we should look, we found exactly what the models predicted. So too with Big Bang cosmology - it makes a series of predictions, and we have observed many of the things predicted by that model (like the cosmic microwave background). We have never observed anything that contradicts the model.
So the problem in this thread has not been the science. It's been the silly insistence by some posters on trying to prove that science is based on faith just as much as religion, and so their religious beliefs should be just as valid as the scientific model. While they are welcome to their opinions, in reality they amount to complete and utter bullshit. Science takes exactly one thing on faith: that what we observe is actually what is happening. We take on faith that, when we look at the moon at night, we're actually looking at the moon and not trapped inside of the Matrix.
If this thread has shown us one thing, it's that scientific principles are extremely difficult, and maybe even impossible to learn if an individual insists on maintaining a pre-existing belief or tries while learning to prove that science is based on something just as flimsy as their own faith. The strength of science, the very reason if continues to give us ever more accurate models of the Universe and produce real-world applications like computers, medicine, and everything else we use every day is that sciencits are not tied to a specific belief, and they are not personally invested in any particular model. They are concerned only with the evidence and the greatest degree of accuracy possible, which allows models to be changed or even thrown out altogether to incorporate new evidence.
The Big Bang model has shown through observable, testable evidence to be extremely accurate. That many people cannot understand this evidence is irrelevant.
PS - thank you very much, cavediver and Son Goku, for all of your contributions. I learned quite a bit from both of you, even if some people didn't learn anything at all.
  —"Rahvin"
Brilliant wording and brilliant summation of what human race seems to have proven beyond reasonable doubt so far. My hat goes off to you Rahvin(may God bless you - kidding, kidding - HEHE ).
Edited by Agobot, : No reason given.

Agobot
Member (Idle past 5645 days)
Posts: 786
Joined: 12-16-2007


Message 405 of 410 (460069)
03-12-2008 2:31 PM


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