Quizzes & Puzzles4 mins ago
Spacetime ?
I've looked through the titles of many books but none of them explain how
spacetime was created out of nothing. That has no more validity than saying it was created by God or who created God ?
Can anyone enlighten me or tell me a book that tries to ?
spacetime was created out of nothing. That has no more validity than saying it was created by God or who created God ?
Can anyone enlighten me or tell me a book that tries to ?
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For more on marking an answer as the "Best Answer", please visit our FAQ.The role of diffeomorphism invariance in precluding the existence of any pre-assigned (kinematical) spatio-temporal properties of the points of the manifold (even locally) that are independent of the choice of a solution to the field equations (no kinematics before dynamics). The physical points of space-time thus play a secondary, derivative role in the theory, and cannot be used in the formulation of physical questions within the theory (they are part of the answer, not part of the question).
I think the true answer is still "nobody knows" - so far our science only goes back with any degree of certainty to a small fraction of a second after the Big Bang, and for the time being it's probably important to sort all that out before we can push back still further.
To try and sort out the mess of how things started there are two ideas that occur to me, though both are speculative. Firstly, the Universe could be self-contained. The crisis of its being created out of nothing then stops existing because there is no nothing from which it could not be created. There are probably far too many negatives in that sentence... the point is that it might just not be possible to ask what happened before the Big Bang, because there is no meaning of "before". Time, and everything, starts with the Big Bang.
It's not very satisfactory as an explanation, perhaps, but is equivalent to the meaninglessness of "what is larger than infinity?" and other non-questions.
A second possibility is that rather than being self-contained there could be some higher space in which the Universe lives. In this scenario, on which you could then put M-Theory or String theory or such, the Birth of the Universe is natural because in any theory in curved or flat space-time you find that there is no such thing as a perfect vacuum, so that spontaneous creation of the Universe is not only possible but inevitable. Such a higher-dimensional space in which the Universe lives would then, with equal inevitability, be capable of sustaining many other "Universes". I am describing the "multiverse" view of things here, but it's mathematically plausible. The problem is that it's difficult and almost certainly impossible to confirm experimentally and so remains and will remain speculative, and could also be regarded as not really Science.
I expect that a good place to turn to will be Hawking's book "The Grand Design", but I've not yet read this myself.
To try and sort out the mess of how things started there are two ideas that occur to me, though both are speculative. Firstly, the Universe could be self-contained. The crisis of its being created out of nothing then stops existing because there is no nothing from which it could not be created. There are probably far too many negatives in that sentence... the point is that it might just not be possible to ask what happened before the Big Bang, because there is no meaning of "before". Time, and everything, starts with the Big Bang.
It's not very satisfactory as an explanation, perhaps, but is equivalent to the meaninglessness of "what is larger than infinity?" and other non-questions.
A second possibility is that rather than being self-contained there could be some higher space in which the Universe lives. In this scenario, on which you could then put M-Theory or String theory or such, the Birth of the Universe is natural because in any theory in curved or flat space-time you find that there is no such thing as a perfect vacuum, so that spontaneous creation of the Universe is not only possible but inevitable. Such a higher-dimensional space in which the Universe lives would then, with equal inevitability, be capable of sustaining many other "Universes". I am describing the "multiverse" view of things here, but it's mathematically plausible. The problem is that it's difficult and almost certainly impossible to confirm experimentally and so remains and will remain speculative, and could also be regarded as not really Science.
I expect that a good place to turn to will be Hawking's book "The Grand Design", but I've not yet read this myself.
fao Zacs
Yes! shopping again this am. but had a head wind on return and was freezing!
Am going to look at a more macho version on Wednesday.
Met a few folk on my trip - much better to be able to pass thetime of day - I must have missed a lot when I used to drive.
From home to local Co-op (super shop with everything I need) is probably no quicker by car when you consider all the stopping at junctions etc.
Nice to hear from you.
goodnight
Yes! shopping again this am. but had a head wind on return and was freezing!
Am going to look at a more macho version on Wednesday.
Met a few folk on my trip - much better to be able to pass thetime of day - I must have missed a lot when I used to drive.
From home to local Co-op (super shop with everything I need) is probably no quicker by car when you consider all the stopping at junctions etc.
Nice to hear from you.
goodnight
No - that does have more validity
Occam's razor says you remove all unneeded complexity
Thus space time being created from nothing is preferable to God coming from nothing and creating space time which in turn has more validity than sparky the robot coming from nothing, creating God who creates space time.
When Hubble measured the distance of the galaxies he discovered what came to be Hubble's law - the further away a galaxy is the faster it appears to be receding from us.
If the Big bang was an explosion you wouldn't get that - all fragments of a hand grenade fly apart at roughly the same speed.
What this tells us is that the 'space' between them is expanding - the further away the more space to expand so the faster they seem to be receding.
The classic analogy is currents in a loaf of bread which is expanding as it rises.
Trace this expansion back and you come to a point of creation.
It may not make sense to you that things appear out of nothing because at the scale that we live our lives they don't but at the subatomic scale things flash in and out of existence all the time.
http:// en.wiki pedia.o rg/wiki /Quantu m_foam
Occam's razor says you remove all unneeded complexity
Thus space time being created from nothing is preferable to God coming from nothing and creating space time which in turn has more validity than sparky the robot coming from nothing, creating God who creates space time.
When Hubble measured the distance of the galaxies he discovered what came to be Hubble's law - the further away a galaxy is the faster it appears to be receding from us.
If the Big bang was an explosion you wouldn't get that - all fragments of a hand grenade fly apart at roughly the same speed.
What this tells us is that the 'space' between them is expanding - the further away the more space to expand so the faster they seem to be receding.
The classic analogy is currents in a loaf of bread which is expanding as it rises.
Trace this expansion back and you come to a point of creation.
It may not make sense to you that things appear out of nothing because at the scale that we live our lives they don't but at the subatomic scale things flash in and out of existence all the time.
http://
I'm sure it must be connected with uncertainty. I'd suggest because it isn't certain spacetime couldn't emerge from nothing, it inevitably did. And given that something and nothing are the only 2 states we can conceive of, they cover all eventualities between them, one has to be: and I'd suspect the natural (default) state to start with is nothing which therefore doesn't need to be created.