Before the Big Bang

Hmmm, your sounding a bit definitive here, SG. Where's this coming from? There's many possibilities here - from a brane perspective there's no pre-phase transition structure other than 'normal' Nd space-time; and with no-boundary, the transition is at the other extreme - i.e no transition.

I agree, it's a tough one. I guess I've always gone with Hartle Hawking, as it seems more in tune with the spirit (or my perception of the spirit) of FRW and GR in general. If you can appreciate the globe (north pole, south pole) analogy of a closed FRW, you have gained a real insight into GR. You can then take that picture and easily expand into the current FLRW picture.Talking about pushing through the singularity, while quite possibly what happened, does not give such the large-scale insight. So I guess I'm more reacting out of defense of my own presentation, and others may well say that FRW with its singularity is more in tune with your picture than mine, where I ignore the singularity by silently invoking No-Boundary.It is the age-old problem of knowing what to present - we know the SM is 'wrong' but it is still the only concensus! I remember slamming a guy on sci.phys.research in the very early nineties for presenting FLRW with +ve lambda as the truth - he claimed his group had evidence of +ve lambda, and my response was- so what? Until it is concensus, you teach the SM, as in FRW. I should look him up and let him know that he's ok to continue now BTW, loved your comment: very, very true...Edited by cavediver, : No reason given.

Hi ICANTFirst let's clear something up. The Universe may or may not have a time before the T=0 of the Big Bang. Classical General Relativity suggests that there is no T<0, and certain quantum investigations suggest that this remains true - the Hartle-Hawking No-Boundary proposal being the original. Other quantum investigations through string theory and other ideas suggest that the Big Bang was merely the start of our particular corner of existence. In this case, the true Universe is much larger and time may well be infinite in extent going backwards. Or it may not and we are back to our original T=0 of the Big Bang, just now sometime long before our own Big Bang.Let's take our original case of a Big Bang with no T<0. Let's look at God's view on the Universe from outside. He sees (I know 'cos he told me) something that looks like a large beach ball. Our entire Universe is the surface of the beach ball - not just now, but the entire past and the entire future - each point on the beach ball is a point in space-time: your birth, your wedding ceremony, your death, the death of the Sun, etc, etc.There is also the point of the Big Bang. From outside it doesn't look special at all. It's just another point on the ball. Admittedly, if you look closely enough, you will see that there is something special about that point, but nothing drastic. It is certainly not a point of creation. If God did create this Universe, he created the whole of it - the whole beach ball - in which case the moment of creation is all around us, in our past and in our future.If you were to travel through space and time back to the Big Bang, able to survive the temperatures and gravitational stresses, you would approach the region around T=0. As you tried to go back further, before T=0, you would find yourself travelling forward in time again, to T>0. No matter how you tried, you would find that the time 'before' T=0 is actualluy the time 'after' T=0. You would not see matter and energy appearing from nothing. You would start to appreciate the real nature of matter and energy, that they are like ripples on a pool:Ripples appear to be 'created' from a point on a pool, from where they spread out, but there is no 'somewhere' from where the ripples come. Ripples are just a feature of the pool.Matter and energy appear to be 'created' from a point in the Universe, from where they spread out, but there is no 'somewhere' from where the mattrer and energy come. Matter anmd energy are just a feature of the Universe.All of this is our (i.e Relativists) view on the Universe.This view is true even if the Universe is infinite in extent either through space or through time as well! These infinities are only aspects of our Universe from our internal viewpoint. From outisde it is very easy to compact these infinities into a nice manageable finite sized beach ball. This is what we do all the time in Relativity, so if we can do it, I'm more than sure God can.Whether the Universe is infinite or finite, it just looks like the same beach ball to God. The real fundemental question for us is why does the beach ball exist? Your answer is that God made it exist. Some others may have different ideas - such as it has to exist! That's an interesting topic in itself... That's all fine. But this has nothing to do with the Big Bang, T=0, and 'something from nothing'. The Big Bang is just one, albeit interesting, point on this wonderful beach ball we call the Universe...

Ok, it looks as if I've completely failed to get across what I'm trying to say No, it can't. I'm saying that we don't know. No-one is claiming that there definitely wasn't a T<0, nor that there definitely was a T<0. We don't know. What I am saying is that both cases make sense, and neither require any concept of something from nothing. You're missing the big issue. Time as we know it is purely a property of our Universe. When we have God's view of the Universe, there is no before or after. If there was a creative event, it did not occur in our past, because our future was brought into being at the same event. Going back in time just takes you to one end of our Universe. That end is no more the 'beginning' of the Universe that any other point - such as my now, sat here typing at my computer. What you are asking for - a before the Big Bang - just does not exist as a concept (assuming no T<0)This isn't easy to grasp, I admit, but you have to let go of this idea that our normal concept of time applies outside the Universe. It didn't appear - it just is. Just as right now, right here just is. And now, and now again. These moments didn't 'come' from the preceding moment. They all just exist, and we experience these moments in this bizarre sequence we call time. But all of theose moments just exist. To single out the singularity and to ask 'where did it come from' is just silly, becasue you don't ask where all the other moments in the Universe come from! All of them just exist...

And herein lies the problem. We have multiple posters (including two professionals of the subject) spending a great deal of time attemptng to explain an incredibly deep concept to this layman here, but this layman is so totally incapable of learning anything, so stuck is he in his preconceived ideas with no desire or inclination to relax those ideas to take in something new. What's that about old dogs and tricks?No ICANT, it is not STUPID to compare the Universe to the Earth. I used to do it all the time for my students, whether they were postgrad, undergraduates, or high-school. It is an analogy used to try to explain the situation. Your declaration does indeed make something look stupid, but it is not the analogy. The humble response would be - I'm sorry, I don't quite understand your explanation; can you elaborate please?And your suggestion that Big Bang theory should be dropped - do you really set yourself up so high as to think that you have a valid view on this. What about easier subjects like neuroscience? Could you give the surgeons some advice as well? They sure could use it from this pastor here, who suddenly seems an expert on subjects that take normal mortals years and years of dedicated study to gain a respectable understanding.You disappoint me...Edited by cavediver, : No reason given.

The arrogancy is simply astounding. You don't have a billionth of the grounding to even begin to make a comment on this, yet you presume to question an entire discpline. Do you really not understand the simple concept that if there were some mystery here, there would be thousands of papers putting forward a thousand explanations of what might be happening? As it is, there are NO papers on this becasue it is a NON issue.And BTW, it is Professor Hawking. He stopped being Mr Hawking forty years ago around the time he was told he had six months to live.

What part of "it is Professor Hawking" do you not understand???? At the very least it is Dr Hawking. Why are you so intent on being so insulting to someone who has spent the best part of 40 years in a wheelchair, and has been unable to even speak for the past twenty years. Do you tend to kick cripples when you see them as well? Not at all. The singularity in a black hole is an end-product. The singularity at T=0 of a big bang cosmology is a start-product. It doesn't come from anything. He does not use the word "arise" in the sense you are reading.

I am holding a beach ball. It is made of plastic and has swirls of colour. Just underneath the beach ball there is a place where:The beach ball does not exist
The plastic does not exist
The colour does not exist
The swirls do not exist.Yet if I move upwards I encounter a point on the beach ball: the "start" of the beach ball. But how can this one point on the beach ball contain all of the elements: plastic, colour, swirls, etc that will become the beach ball? Where did all of these elements come from when underneath this point is "nothing"??? Of course, becasue this is how I do science. Thank you for being not only so utterly arrogant but so incredibly insulting. You really think that there are areas of science that I dare not question for fear of the answer??? Are you serious??? For fear of perhaps having to acknowledge that there is a god behind it all? And if I already acknoweldge this god, what then would be my reasoning???Oh, your asnswer... ever looked at a river? Ever thrown a stick in the river? Are you so utterly sure that that stick will immediately move downstream?Wind is strong easterly over London. I stand on the pavement in Windmill St, Soho. Which direction do I feel the wind blowing?

Yes, no, no, no, no, no, etc... but irrelevant. His title remains. Using Mr is incorrect. You are aware of his correct title. To use Mr is therefore an insult on your part. That is noted. Ask your wife how she would feel if someone started to deliberately refer to her as Mr.... Just read it again...

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General relativity demands that singularities arise under two circumstances.

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First, a singularity must form during the creation of a black hole. When a very massive star reaches the end of its life, its core, which was previously held up by the pressure of the nuclear fusion that was taking place, collapses and all the matter in the core gets crushed out of existence at the singularity.

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Second, general relativity shows that under certain reasonable assumptions, an expanding universe like ours must have begun as a singularity.

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Better? Two circumstances... "must form" falls under the first circumstance. Yes, though you better understand what that last word means in this context, as you have used the word twice in your question, with two very different meanings. I don't "need" the point. It is just part of the beach ball, as is every other point on the beach ball.

Of course, some of us were at the actual lectures

Don't worry - you wouldn't have been alone. For some crazy reason, the lectures had been advertised around town as 'public lectures' open for everyone. So they were packed out with joe-public all expecting something digestible. It was quite embaressing actually. But there was worse. The lectures were being introudced by Sir Michael Atiyah, a genius of a mathematician from the Wizarding School of Mathematics and master of Trinity at the time. At the end of the first lecture, Atiyah stood up, thanked Hawking (or Penrose - can't remember who went first), and invited the audiance to offer up any "pertinent" questions. With that one word, he cast a silence spell over the entire audience. We desperately wracked our brains trying to come up with something worthwhile to say to simply break the god-awful silence!!! In the end, as I remember it, only Atiyah actually asked a question... (though Gibbons may have as well)Good times...

Oh well, who cares about VAT returns... nothing like a cosmology thread summary to distract you from urgent work.ICANT has almost completely failed to understand Hawking's lectures... no disgrace as this is not beginners' stuff. However he does disgrace himself in assuming that he does understand it and by making idiotic statements such as We also have Which is a separate issue from much of what has been discussed but is simply a misunderstanding of the nature of mass/matter. If the Universe has an earliest time, it does not need an injection of mass/energy at this point. Mass and matter are aspects of the Universe itself - ripples in its struture. One cannot insert pre-existing rippples into the Universe - this is nonsense.Ok, we have confused ourselves with various T=0 scenarios so I thought some pictures were in order... Here we have ths standard big bang scenario. The black dot is the singularity and the universe expands away from this point through time (vertical) and space (horizontal) This is essentailly the south pole region of our globe analogy. I have left the top of th universe off as we don't know yet whether it will close back up or spread apart for ever. The globe analogy assumes it closes back up but this is far from certain and probably unlikely given current evidence. I should also stress that the Universe is the surface of this cup/cone shape. Inside/outside/above/below (the white region) is non-existence. You cannot say any point outside the Universe is 'before' or 'after' the Universe because these points simply do not exist. They are simply there for us to be able to take a God's-eye view on the Universe.Now, the first major attempt to get a quantum correction to the big bang picture was with the Hartle-Hawking no-boundary proposal. It makes a huge difference to the above picture... see: Spot the difference What Hawking and Hartle managed to do was remove the annoying singularity, and replace that region with a nice bit of Euclidean space where 'time' is simply a spatial dimension. It is only as you move upwards does time smoothly become its familiar self with causal and temporal properties. There was no 'before' in the first picture, but now there is DEFINITELY NO BEFORE!!! as there is simply no time-like dimension in the vicinity of the point of interest!That's the 'Universe with an earliest time' dealt with. Now we come to: Here the quantum corrections have revealed that the Universe did not begin at T=0 of the big bang, but emerged from an earlier time. This enlarged Universe may well have been eternal, stretching back infinitely into the past... or it may well have an earliest time, just not at T=0, but at T=-?? somewhere to south of our diagram.Finally, the Universe may well be embedded within a larger space-time - larger in physical size, number of dimensions, or it may have a very different nature altogether - and multiple universes may well be springing into existence with their own big bangs: This picture represents a whole range of possibilities: chaotic inflation, ekpyrotic universe, the 'Landscape' of string theory, etc. Of course, the question is then where did this larger Universe come from? Any of the possibilities we have considered so far could equally apply to this larger space...Ok, so how does God possibly fit into any of these pictures? The most common idea, espoused here by ICANT but also many theists, the Vatican , etc, etc is also the most incorrect from a relativists point of view:.
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. Here we see God magicking the Universe into existence at T=0, and the Universe evolving on from here. The probloem is this presupposes 'time' as continuing outside the Universe, 'before' its existence. The more 'logical' view is: This retains time and space as integral parts of the Universe. And if the Universe is eternal and has no beginning... does this preclude creation? Of course not... Hope this clears the muddy water a little... if not, start a new thread and I'll try and devote some time. Now, about that VAT return

The only stupid question is the one not asked I need up-down on the page to represent the time dimension, so I've only got left-right and back-forward (i.e. perspective on the page) to represent space. Take a horizontal slice through my cup. This the Universe at a particluar time. You get a circle, and this circle represents the whole Universe at that moment. As time proceeds, you go up the page, and the circles get larger. This is the Universe expanding. As you down the page, back in time, the cirlces get smaller and smaller until they collaspe into a point - the singularity in classical cosmology.