God exists as per the Kalam Cosmological Argument (KCA)

1. Complete nonsense.We have yet to experience anything that "begins to exist" so to claim that all things A such that A "begins to exist", implies A "has a cause for its existence" is simply making propositions about fairies' wings.Everything we have ever thought of as a "begins to exist" is merely a change or shifting of form, whether at the level of mineral, chemical, atomic, sub-atomic, or field. This includes the much mentioned virtual-particles/pair-creation. The only thing that "begins to exist" is our terminology for the new form.The only possibility we have seen for something having a semblance of "begins to exist" is in the cosmological space-times of General Relativity (and related and expanded theories), of which a subset form the basis of Big Bang cosmology. These fall into two sets: those that have no-prior cause, and those that do. Those that do explicity break proposition 2.The KCA simply reveals an immense ignorance of modern physics - not surprising given that the KCA belongs to an age long ago...Edited by cavediver, : No reason given.Edited by cavediver, : No reason given.

Sure GR is essentially an engine for churning out space-times. You think of some properties of your desired space-time (matter content, symmetries, etc), plug them in, and out pops a space-time (or family of space-times).For example, let's say that we want to know the space-time associated with a spherically symmetric blob of matter. The space-time naturally has to be spatially spherically symmetric, and we assign our blob of matter to the origin. With a bit of 2nd order PDEs (made simple by the symmetry) and some algebraic manipulation, out pops the Schwarzschild solution. It has only one free parameter: M, the mass of the blob. So in a weak sense you could call the Schwarzschild space-time, a whole family of space-times parametrised by the variable M. There is no non-trivial variation of the space-time as you vary M, unless you set M to zero and the space-time flips back to flat space.If you considered a rotating blob, with mass M and angular momentum J, you get the Kerr family of space-times. This is more interesting because you can have (in geometric units) J=0 (reverts to Schwarzschild), J < M (classic Kerr), J=M (extreme Kerr), and J > M (naked singularity Kerr).If we decide that we want GR to give us a space-time that is isotropic, homogeneous, and filled with an even distribution of matter (i.e. what we believe our Universe to be on the largest scales), then it gives us the FRW space-time, with the amazing feature that it has an earliest time in the initial singularity. If we add in a cosmological constant, then the space-time family includes the one with CC=0, those with CC -ve and those with CC +ve. And these all have different global features. Here I am saying that you can modify the basic FRW space-time by addition of CC, other parameters, string/membrane corrections, etc, that give the space-time a T<0, such that the expansion starting at T=0 has a definite past (cause), but then this gives the space-time an infinite past thus breaking proposition 2 that the Universe has a finite past.Edited by cavediver, : No reason given.Edited by cavediver, : No reason given.

The good reverend appears to be ignoring messages of substance We can but try again... 1. Complete nonsense.We have yet to experience anything that "begins to exist" so to claim that all things A such that A "begins to exist", implies A "has a cause for its existence" is simply making propositions about fairies' wings.Everything we have ever thought of as a "begins to exist" is merely a change or shifting of form, whether at the level of mineral, chemical, atomic, sub-atomic, or field. This includes the much mentioned virtual-particles/pair-creation. The only thing that "begins to exist" is our terminology for the new form.The only possibility we have seen for something having a semblance of "begins to exist" is in the cosmological space-times of General Relativity (and related and expanded theories), of which a subset form the basis of Big Bang cosmology. These fall into two sets: those that have no-prior cause, and those that do. Those that do explicity break proposition 2.The KCA simply reveals an immense ignorance of modern physics - not surprising given that the KCA belongs to an age long ago...

I'm not 100% sure what you're asking, but how's this...Ever since SR and Minkowski, we have known that our Universe is based upon a four dimensional space, with a non-definite metric: one of the four dimensions appears with opposite sign to the other three in the space-time metric - usually this is the t-time dimension. This indefiniteness introduces a causal structure to space-time. Space-time "evolves" from past to future, always obeying causality: point p can only be affected by events in p's past light-cone and point p can only affect events in p's future light-cone.In a infinite past space-time, there are always past light cones, and no first cause external to the space-time is required.In the classical Big Bang scenario, past light cones all converge on the past singularity. Admittedly, this past singularity is the perfect point to posit God, fairies, the Illuminati, Paul Bunyan, etc.This is where Hartle and Hawking tried their hands at some early quantum cosmology. By looking at first order quantum corrections to the Big Bang, they found that you can remove the singularity and patch that part of the space-time with a Euclidean region of space. This is four-dimensional space with definite metric. It has no causal structure, and no cause and effect. It is like an elliptic differential equation (2OPDE)- it is solved by consistency with the surrounding boundary conditions, rather than evolving the solution as with the, e.g. the wave equation. There is thus no "beginning" to the Universe any more, just an initial time-less region from which springs our causality following space-time.In this case, the cause of the "beginning" of the Universe, if one is insisted upon, is the rest of the Universe. It matters not that happens to be forward in time of the beginning. As I have been saying here for the last four years, the Universe just IS

No problem - and yes, they do When I say Cosmological Constant, I am refering to the original CC of General Relativity, and unsurprisingly, it is a constant So whatever value it has at T=0, or T=-infinity, it has this value for all values of T. That is why we only have three basic cases: 0, -ve , and +ve. Actually, it's a bit more complex as you can have CC dominating or matter dominating, and this creates a different behaviour. I'll get round to describing these tomorrow.When I mentioned "The dark energy component could well decrease with expansion", I am talking about a non-constant vacuum energy component. This is not the Cosmological Constant, but a similar energy density resulting from quantum field theory, string theory, or some other extension to normal GR. This gives an infinite variety of possible space-times, as the energy density's time dependence could be literally anything (obviously observations of our actual Universe reveal severe constraints to what this dependence can be.) Yes, we could.

I see that yet again, you completely ignore my complete destruction of the KCA. You can ignore what I write, but it is in plain view of everyone else We can but try again... 1. Complete nonsense.We have yet to experience anything that "begins to exist" so to claim that all things A such that A "begins to exist", implies A "has a cause for its existence" is simply making propositions about fairies' wings.Everything we have ever thought of as a "begins to exist" is merely a change or shifting of form, whether at the level of mineral, chemical, atomic, sub-atomic, or field. This includes the much mentioned virtual-particles/pair-creation. The only thing that "begins to exist" is our terminology for the new form.The only possibility we have seen for something having a semblance of "begins to exist" is in the cosmological space-times of General Relativity (and related and expanded theories), of which a subset form the basis of Big Bang cosmology. These fall into two sets: those that have no-prior cause, and those that do. Those that do explicity break proposition 2.The KCA simply reveals an immense ignorance of modern physics - not surprising given that the KCA belongs to an age long ago... Probably a wise choice for you Simple - that "prior cause" is the infinitely extended time dimension back towards T=-inifnity. These space-times never "begin to exist".Edited by cavediver, : No reason given.

I never said that either of us had. What we have in common is that we are both theoretical physicists and have a little bit more knowledge of this subject than your amateur musings It is not our fault that you are only aware of the layman/popular science accounts of Big Bang Cosmology. If you have a genuine interest, perhaps you could enrole in a cosmology department somewhere?Now, go back and answer my refutation of the KCA

The reason I do not reply to you anymore, ICANT, is because you are incapable of understanding anything that I have ever written - you always think that your own spin on what is written takes precedence. Here is a perfect example: Rubbish - I demolish the argument without even mentioning the Big Bang. It falls apart immediately:

quote:

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1...Anything that begins to exist has a cause for its existence

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Complete nonsense.We have yet to experience anything that "begins to exist" so to claim that all things A such that A "begins to exist", implies A "has a cause for its existence" is simply making propositions about fairies' wings.Everything we have ever thought of as a "begins to exist" is merely a change or shifting of form, whether at the level of mineral, chemical, atomic, sub-atomic, or field. This includes the much mentioned virtual-particles/pair-creation. The only thing that "begins to exist" is our terminology for the new form.

I demolish proposition 1. The argument fails with out it. Proposition 1 does not mention the Big Bang. All very simple... That was what he thought at the time. He probably still does, from time to time. I haven't asked him about it recently. I have emphatically stated that there is no before T=0 in the standard model Big Bang cosmology. Yes, exactly. In the Big Bang cosmology, that is a meaningless question. There is no T<0. Therefore there is no "prior" T=0. It is just as incorrect to say that there is "no thing" prior to T=0, as it is to say that there are no pink elephants prior to T=0, and equally so with saying that there are pink elephants prior to T=0.What do people wear on the 32nd of January? Nothing? So they go naked?What you still haven't learnt is that neither Hawking nor I deal in absolutes - I will describe different possibilities, and what those possibilities mean. You keep trying to quote us both, when we are talking about one specific possibility, and then claiming that that is what we believe.

Err, this is the conclusion of the KCA. You can't just assume it because you happen to think that it makes sense oh dear, you really haven't quite grasped the issue...

After all this time, you still don't get it. The Universe has never not existed. It exists for all time. Even if that time is finite in extent. Oh FFS, how many times? It doesn't. There has never been 'no thing'. There has always been 'some thing', whether there is an earliest time or not.

ICANT, this question doesn't make any sense, primarily because as ever you are using terms that are outside your understanding. Wrong. Meaningless. These quotes demonstrate that yet again your understanding is so below par for this topic that it is a complete waste of time. I tried to stretch your mind beyond this primitive thinking in the days when I still had some measure of patience. But you spent all your time arguing and very little time listening and learning. The Universe never 'began' to exist. It has always existed. Even if that is only for a finite amount of time.

They don't. In a standard 4d (semi-classical) General Relatvity, everything that exists is the Universe. Space-time and the quantum fields are part of the same "fabric". Think of space-time as a beach-ball, and the quantum fields as layers of paint on the beach-ball.The BB is just one point on the beach-ball. That point has no cause other than the actual existence of the beach-ball itself.Edited by cavediver, : No reason given.

There was no 'bad math' in the slightest. The cosmological constant is a perfect and necessary part of General Relativity. All Einstein did was pick a value for the CC that gave the Einstein Static Universe, because like most others at the time, he believed the Universe was static. Observational evidence from Hubble is what demonstrated his 'error' - the reason he regarded it as such a huge blunder was because he could have made the prediction that the Universe was either expanding or collapsing had he not been so blinded by the convention that the Universe was static. You really have lost sight of what is being discussed here. We have a claim that the KCA is a sound argument. All I need to demonstrate that the argument is not sound is to point out uncertainty within its assumptions. There are many possibilities, most of which I haven't touched on in this thread. I have no idea which are correct. But that is not important for this current discussion.

No, the beach ball is the enire 4d Universe, Big Bang and Big Crunch and everything in between. Pick a point as the BB. This is T=0. T=10^-43 is a tiny circle around the T=0 point. We do not have the technology yet to describe what is happening inside that circle. Everything outside this circle is understandable with our present physics.