What's The Maximum Speed A Falling...
ChatterBank1 min ago
What is beyond the universe?
I watched the Big Bang programme on Panorama last night. I've never bought into the Big Bang Theory so it's nice to see that it is losing momentum among some scientists. Obviously no one can answer my question with any certainty so just your thoughts and theories are welcome. Basically what I am wondering is, if the universe is expanding, what is it expanding into? Is the universe creating time and space at its outer reaches as it expands?
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ABerrant, Well of course you couldn't make it all the way through . . . you'd bump into Australia!
But cweusly, no, I cannot prove that a journey into 'the third dimension' even given an indefinite time to complete it would produce a similar outcome. At this point the global and topological geometry of the universe remains to be determined. The objective of my analogy was to illustrate in the simplest possible terms the prevailing view of a universe without centre or edge.
If you have a simpler more concise method of illustrating a universe with no centre or edge, I'd be delighted to see it. If you disagree with a no centre no edge geometry I'll consider your views on that issue as well. At this point it's all still pretty much up in the air anyway, isn't it?
But cweusly, no, I cannot prove that a journey into 'the third dimension' even given an indefinite time to complete it would produce a similar outcome. At this point the global and topological geometry of the universe remains to be determined. The objective of my analogy was to illustrate in the simplest possible terms the prevailing view of a universe without centre or edge.
If you have a simpler more concise method of illustrating a universe with no centre or edge, I'd be delighted to see it. If you disagree with a no centre no edge geometry I'll consider your views on that issue as well. At this point it's all still pretty much up in the air anyway, isn't it?
I don't think there is much emperical evidence for the 4D torus - it's rather one of a number of possibilities.
Einstein came up with what are now called the Einstein Field Equations but never solved them they describe the shape of the Universe.
http://en.wikipedia.o...stein_field_equations
There are a number of solutions which give different geometries
So it is one thing to see what geometries are possible - quite another to derive a test to see which of the possible solutions is in fact the case.
This is similar to where we are with string theory
The fact that it has been so long without evidence is mostly to do with the experimental difficulties in the sizes involved we are talking about 10to the power -34 meters here - 1/100,000,000,000,000 the size of an atom.
There are good reasons for thinking that the current model is not the final story - everything seems to work in sets of 3 and there is a definate pattern. This implies an underlying structure in the same way that the periodic table implied the current model that Gell-Mann came up with.
Truth is we are at a stage in physics where the theories are often self-consistant and explain what we already know but that direct observations to confirm them are beyond or are at the limit of our technology
Indeed in some cases they may be beyond any technology.
Other examples include gravitational waves and the multiverse
Einstein came up with what are now called the Einstein Field Equations but never solved them they describe the shape of the Universe.
http://en.wikipedia.o...stein_field_equations
There are a number of solutions which give different geometries
So it is one thing to see what geometries are possible - quite another to derive a test to see which of the possible solutions is in fact the case.
This is similar to where we are with string theory
The fact that it has been so long without evidence is mostly to do with the experimental difficulties in the sizes involved we are talking about 10to the power -34 meters here - 1/100,000,000,000,000 the size of an atom.
There are good reasons for thinking that the current model is not the final story - everything seems to work in sets of 3 and there is a definate pattern. This implies an underlying structure in the same way that the periodic table implied the current model that Gell-Mann came up with.
Truth is we are at a stage in physics where the theories are often self-consistant and explain what we already know but that direct observations to confirm them are beyond or are at the limit of our technology
Indeed in some cases they may be beyond any technology.
Other examples include gravitational waves and the multiverse
Thanks Jake. Some people might say (..and I'm not one of them), but some might say that in the absence of empirical evidence, we need to assume that a proposition is nonsense - until such time that a proof is forthcoming - especially when the proposition is so far removed from our everyday experience of reality that it seems to defy all common sense.
I see that argument from paranormal sceptics in religion and spirituality all the time. Why should it apply there and not to these areas of cosmology that are right at the limits of our understanding?
I see that argument from paranormal sceptics in religion and spirituality all the time. Why should it apply there and not to these areas of cosmology that are right at the limits of our understanding?
Er I think Flob that according to Hubble's law *Everything* is at the centre of the Universe!
I've watched the program now - it does seem that there is increasing interest in this idea but it's still rather fringe - despite people like Roger Penrose's interest.
It seems to me that the great attraction for many is to try to come up with a multiverse model which gets around the Goldilocks problem of a Universe so fit for life.
However in doing so they are creating as many problems as they are solving - and I'm sure they would acknowledge this.
This biggest issue the absence of a theory of Quantum Gravity - we have no accepted model of how time works in extreme cases. So the guys at PI are taking a theory with no experimental evidence and making a bunch of assumptions and seeing what comes out of it - of course they're all convinced there was a "before" because that's what they're hired to research.
Roger Penrose's ideas neatly illustrate the sort of problems you get into. His point is that a Universe that decays to the point that no matter exists (and we think that given enough time that will happen based on existing evidence) there is no longer a meaningful concept of time or scale and the Universe becomes infinitely large and infinitely small at the same time and time vanishes and the cycle repeats.
Er sorry? - time stops - yes no matter no time - then it repeats - that phrase has a notion of time in two out of 3 words - it is pretty meaningless.
The other problem is that these only put off the genesis problem - We thingk there was a before but we don't know how that came to be - seems a bit like putting God there and saying don't ask where God came from.
I wouldn't say that these ideas are nonsense but to be they are theoreticians stabbing in the dark. Until there is a proven theory of Quantum Gravity all of this seems highly speculative and as one of t
I've watched the program now - it does seem that there is increasing interest in this idea but it's still rather fringe - despite people like Roger Penrose's interest.
It seems to me that the great attraction for many is to try to come up with a multiverse model which gets around the Goldilocks problem of a Universe so fit for life.
However in doing so they are creating as many problems as they are solving - and I'm sure they would acknowledge this.
This biggest issue the absence of a theory of Quantum Gravity - we have no accepted model of how time works in extreme cases. So the guys at PI are taking a theory with no experimental evidence and making a bunch of assumptions and seeing what comes out of it - of course they're all convinced there was a "before" because that's what they're hired to research.
Roger Penrose's ideas neatly illustrate the sort of problems you get into. His point is that a Universe that decays to the point that no matter exists (and we think that given enough time that will happen based on existing evidence) there is no longer a meaningful concept of time or scale and the Universe becomes infinitely large and infinitely small at the same time and time vanishes and the cycle repeats.
Er sorry? - time stops - yes no matter no time - then it repeats - that phrase has a notion of time in two out of 3 words - it is pretty meaningless.
The other problem is that these only put off the genesis problem - We thingk there was a before but we don't know how that came to be - seems a bit like putting God there and saying don't ask where God came from.
I wouldn't say that these ideas are nonsense but to be they are theoreticians stabbing in the dark. Until there is a proven theory of Quantum Gravity all of this seems highly speculative and as one of t
Well jake, if there wasn't a before and the so-called Big Bang was the beginning of out universe, why has it not happened again, ie why don't new universes continually explode into existence from nothing. Or do they? Perhaps dark matter is space and time lying idle waiting to be filled by a new universe. Eh?
