Problems with the Big Bang theory

Nothing exploded.

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Kings were put to death long before 21 January 1793. But regicides of earlier times and their followers were interested in attacking the person, not the principle, of the king. They wanted another king, and that was all. It never occurred to them that the throne could remain empty forever. -- Albert Camus

Whatever! The Big Bang Theory, right? Isn't that what it says?

What explosion?
There used to be a quark-gluon-lepton plasma existing in a rapidly expanding background. That's all the theory says.

Isn't an explosion something that is rapidly expanding material? You guys are splitting hairs. This is crazy!!

As Yoda said, "you must unlearn what you have learned" There was no "explosion", there was rapid expansion of the fabric of space-time. There was no "nothing" "before" out of which the universe sprang, becasue there is no "before". Time as we normally understand it only makes sense some moments after the initial expansion, and is just a feature of our bizarre 3 dimensional perspective on the universe. "stuff" as you call it is merely ripples in the various fabrics that make up the universe: space-time, matter, force... all are aspects of the same thing.As far as the basic Big Bang model is concerned, there is the universe... and that is all. There is no "nothing" "outside" or "before" the universe. These concepts are totally meaningless. There is just a fixed 4 dimensional universe that contains all of time and space, and we have been given a curious 3 dimensional perspective on this universe (possibly by God) that gives rise to our notion of time.There is a valid question of "why is the Universe here?" or better still "why do we have existence?" but these are questions that are firmly in the hands of theology and philosophy, and only a few of us try and make sense of this in science/mathematics. The Big Bang has nothing to do with such questions, it merely describes what the universe looks like at one end of its 4 dimensional existance.And of course there is still the possibility that the universe does extend "backwards" through the Big Bang to a prior time, and could possibily be infinite in extent in the time dimension.Edited by cavediver, : No reason given.

No. The Big Bang theory says that the early universe was very hot, very dense, and expanding.To have an explosion, there would have to first have been something sitting there, quietly, and then suddenly expanding outwards. The explosion is the sudden beginning of the expansion.As far was we know, from the very "first instant of time" (whatever that may mean), the universe may have always been expanding. As far as we know there may never have been a time when the universe (or the material that makes up the universe) was just sitting around, minding its own business.

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Kings were put to death long before 21 January 1793. But regicides of earlier times and their followers were interested in attacking the person, not the principle, of the king. They wanted another king, and that was all. It never occurred to them that the throne could remain empty forever. -- Albert Camus

WOW, finally someone with a little common sense!!

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I like the idea that basically we have a 4d structure we call the universe.

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Yes, the concept of a four dimensional manifold with a non-positive definite metric certainly does make some other concepts easier to digest. If you can visualize such a thing, then it really illustrates how the question "What caused the universe to exist" -- with time as just another dimension, and visualizing the manifold as existing "all at once" in some fashion, then it easier to think, "it just exists."But be careful about putting to much reality into mathematical constructs. I have done too much pure mathematics; it is way too difficult for me to believe these symbol manipulation games have any sort of reality behind them. Modelling "space-time" as a four dimensional manifold allows us to use differential geometry to predict the results of observations of phenomena to great accuracy -- it is certainly an accurate and useful tool to understanding the universe.But is "time" really just another dimension like the three spatial ones? Heh. Probably not. "Time" is actually what we sense passing, "space" is what we "pass through" when we move. Physical observations show that we do not necessarily understand what time and space really are, but I'm not convinced that the mathematics of GR or any other physical theory does, either.An amusing note, Kant claims that time and space are not real; they are merely abstractions created by our minds to organize our sensory perceptions. I can't convince myself that he is wrong, but I can't convince myself that he is right, either. (I know, I know, "I refute it thus!") If he is right, then General Relativity is an abstract model of something that is already a mental construct. Heh.

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Kings were put to death long before 21 January 1793. But regicides of earlier times and their followers were interested in attacking the person, not the principle, of the king. They wanted another king, and that was all. It never occurred to them that the throne could remain empty forever. -- Albert Camus

Heh, heh... I have done too much pure mathematics to believe that there isn't a reality behind it all But then it is the diversity of mathematical thought that makes it such a great subject.Also, don't forget that it is not just GR that likes to think of time as a dimension... it underpins the entirety of quantum theory. After that, there's not much left!

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I have done too much pure mathematics to believe that there isn't a reality behind it all

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There is a recent thread where Confidence made some sort of claim about mathematics being real. I pointed out to her that I think it's all invented. But I also pointed out that others think it's discovered. Heh. Yeah, diversity.-

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it underpins the entirety of quantum theory.

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Quantum theory is something I'm more familiar with, certainly more so than GR. (And, in fact, operators on Hilbert Spaces were the main thrust of my graduate work in mathematics.) In fact, it was the epistemological questions that quantum mechanics raises that started me down the path to the dark side, heh.

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Kings were put to death long before 21 January 1793. But regicides of earlier times and their followers were interested in attacking the person, not the principle, of the king. They wanted another king, and that was all. It never occurred to them that the throne could remain empty forever. -- Albert Camus

Although given that it works at all and how accurately it works, would lead me to say that at the cosmological scale the difference between what space and time really are and what they are according to GR is negligible. So at that scale I'm perfectly comfortable in calling space and time a 4-D manifold with a Lorentzian metric.
Just like I'm comfortable in calling a cardboard box a cuboid, even though it really isn't if you scale down far enough.In the range 0.000006 meters to 7.3x10^26 meters time acts exactly as if it was another dimension, so I don't think it's too great an error to think of it like that, even though it may ultimately be wrong.Edited by Son Goku, : Minor spelling.

Apart from that really weird region from 2.7x10^22 to 3.2x10^22 meters of course.

Might I ask what cavediver said that made more sense to you than what had been said previously. Cavediver certainly gave a more complete description of the Big Bang model. Which element made more sense than the simplified answer everyone else had repeated over and again earlier (that is, that the Big Bang Model simply says things were hotter and denser, not that they came from nothing).Was it because he added God into his explanation? If that is the reason then that is of great interest to me. There is a recent debate about whether or not we should try explaining science to people in terms of their religion/culture. If you found that simply adding God to the explanation helped you understand some part of the Big Bang Model - then I'd be very excited to hear about it.Depending on your reply, I might start a thread on it.

It seems that way.
I think it is the admittance by cavediver that the origin of the matter is not what the Big Bang is trying to explain. So, whereas we previously had comments on what is meant by the Big Bang, space time and expansion and so forth, finally cavediver hits something that divinebeginning was after, an explanation other than something naturalistic. It seems he just wanted someone to admit that naturalstic explanations do not exist as of yet on how everything arose, or how everything existed forever. Therefore, allowing the possibility of God. This is something I have not seen before, however, I think it has truth in it. For any explanation that excludes God as a possibility, I will look down with a disproving look. Likewise, it seems, you look down on explanations that have a 'God Did It' attached to it.So if I were to appeal to you, I would need naturalistic explanations and quantifications, AND I would need to exclude God as a remote possibility. Likewise, if you would want to interest me, saying that God is not an acceptable answer in science will do just the opposite.Feel free to correct me if I am wrong about some of the assumptions I made about you. But this is what I generally understand from the replies I see.

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Men became scientific because they expected Law in Nature, and they expected Law in Nature because they believed in a Legislator. In most modern scientists this belief has died: it will be interesting to see how long their confidence in uniformity survives it. Two significant developments have already appeared”the hypothesis of a lawless sub-nature, and the surrender of the claim that science is true. We may be living nearer than we suppose to the end of the Scientific Age.’*Lewis, C.S., Miracles: a preliminary study, Collins, London, p. 110, 1947.

Just past Andromeda? Is there something wierd I've missed at the sub-local cluster level?
It's entirely possible that I have.