Big Bang, the start of the universe, and CMBR
Discussion
Ayahuasca said:
Presumably the spot where the BB started is now somewhere in the extant universe, so where is that spot?
That is an impossible question. You are assuming that the big bang happened in a pre-existing location at a pre-existing moment in time.The big bang was the beginning of both space and time.
wisbech said:
The way I think of it is a balloon being blown up from a point. The furthest you can be away from something is the other side of the balloon, there is nothing inside or outside the balloon, just the balloon surface.
Of course you cannot circumnavigate the balloon to prove it is a closed surface because the surface is growing faster than you can travel across it. Toltec said:
Terminator X said:
Apparently that is the "observable universe" with the actual universe being an unknown amount bigger. We will only ever know the OU. Head hurting, must lie down.
TX.
The fun thing that keeps rattling around in my head is that if the OU is 13.8B LY in one direction and the same in the opposite direction then those points in space are further apart than it is possible for them to be given they can only move away from each other at a maximum of C.TX.
While nothing can be more than 13.8B LY away from anything else every point in space can 'see' 13.8BLY in every direction...
Then of course they may not be moving at C, but rather the space between them is expanding.
RSTurboPaul said:
MiseryStreak said:
It’s not a dumb question at all. Intuitively, we are surrounded by space and presume and are told that this space stretches out uniformly in every direction. It is therefore natural to think of this space as having form and a centre. But with the Universe this space is everything, and nothing exists other than it. There is no outside of it as there is no before it (although I don’t believe time exists but that is a another subject).
Just as you can’t have a middle of a set of numbers that stretches to infinity, there can be no centre to an infinite (or apparently infinite) space.
We are the Big Bang. The Big Bang was just the Universe, everything that exists, at a very young age. It became you and me and everyone and everything that you or anyone else will ever see. We are the Big Bang, expanding into infinity.
For all intents and purposes, you (as the observer) are at the very centre of everything you see. But don’t let it go to your head, as so is everybody else.
Because this thread doesn't make my head hurt enough... lolJust as you can’t have a middle of a set of numbers that stretches to infinity, there can be no centre to an infinite (or apparently infinite) space.
We are the Big Bang. The Big Bang was just the Universe, everything that exists, at a very young age. It became you and me and everyone and everything that you or anyone else will ever see. We are the Big Bang, expanding into infinity.
For all intents and purposes, you (as the observer) are at the very centre of everything you see. But don’t let it go to your head, as so is everybody else.
... can you expand on that??
If you don’t mind reading subtitles or if you speak Italian I just found a Ted Talk of his:
https://m.youtube.com/watch?v=xeHHjGKwZWM
Then there’s the real mindf
k of a book by Julian Harbour, The End of Time. I have to admit this lost me halfway through, but I still think the solution to resolving the Quantum world with the macro one, with Relativity, is in the rethinking of time.Ayahuasca said:
Cheers. On delving it seems most believe it was a big stretch rather than a Big Bang in the sense of an explosion. There does seem to be uncertainty as to whether the universe is finite, or infinite. If it is finite, you would expect it to have a centre of mass, which you might consider the centre of the universe and so the very small dense thing that expanded might have ‘been’ there; on the other hand, the universe may be infinite, with no centre of mass, but in that case why does the night sky look mostly black (infinite number of stars = light universe).....
Looking at the surface of the Earth, the two- dimensional bit that we wander around on, where is the centre on that surface?What about if you draw a circle, and consider only the circumference, which bit of the circumference is its centre.
It’s the same with the universe, there’s not necessarily a centre.
MiseryStreak said:
It’s described beautifully by my favourite physics author Carlo Rovelli, in his book The Order of Time. His earlier book, Reality is Not What it Seems, is one of my all time favourite books.
If you don’t mind reading subtitles or if you speak Italian I just found a Ted Talk of his:
https://m.youtube.com/watch?v=xeHHjGKwZWM
Then there’s the real mindfk of a book by Julian Harbour, The End of Time. I have to admit this lost me halfway through, but I still think the solution to resolving the Quantum world with the macro one, with Relativity, is in the rethinking of time.
Is that coming from having some knowledge of the subject (having worked and done research in it), or is it a layman’s speculation?If you don’t mind reading subtitles or if you speak Italian I just found a Ted Talk of his:
https://m.youtube.com/watch?v=xeHHjGKwZWM
Then there’s the real mindf
k of a book by Julian Harbour, The End of Time. I have to admit this lost me halfway through, but I still think the solution to resolving the Quantum world with the macro one, with Relativity, is in the rethinking of time.Kent Border Kenny said:
Is that coming from having some knowledge of the subject (having worked and done research in it), or is it a layman’s speculation?
I wouldn’t even describe it as speculation, more that I find what I have read in mostly popular science books about Loop quantum gravity more agreeable than string theory, as a solution to merging quantum mechanics with general relativity. I studied engineering and Architecture so I’m most certainly a layman.If you read Reality is not what it seems though, it’s pretty convincing. Brian Greene’s The Elegant Universe was my favourite physics book until I read it.
Oscillating strings never sat well with me, I would always end up wondering what the strings were made of. Then there is the huge problem of spacetime that just can’t work at the quantum level.
MiseryStreak said:
I wouldn’t even describe it as speculation, more that I find what I have read in mostly popular science books about Loop quantum gravity more agreeable than string theory, as a solution to merging quantum mechanics with general relativity. I studied engineering and Architecture so I’m most certainly a layman.
If you read Reality is not what it seems though, it’s pretty convincing. Brian Greene’s The Elegant Universe was my favourite physics book until I read it.
Oscillating strings never sat well with me, I would always end up wondering what the strings were made of. Then there is the huge problem of spacetime that just can’t work at the quantum level.
It’s not something that I remember being discussed back when I was a physicist, it does seem to be a bit of “blue sky thinking”, but who knows, it could have something to commend it.If you read Reality is not what it seems though, it’s pretty convincing. Brian Greene’s The Elegant Universe was my favourite physics book until I read it.
Oscillating strings never sat well with me, I would always end up wondering what the strings were made of. Then there is the huge problem of spacetime that just can’t work at the quantum level.
Ayahuasca said:
Forgive my non-physicist questions on this, but we keep hearing that before the BB the universe was compressed into a tiny area. Where was that area? If we can observe galaxy GNZ11 13.8 billion light years away, and that galaxy was formed relatively shortly after BB, and the light from that galaxy is red-shifted, so it is travelling away from us, and presumably also away from the site of the BB, does that mean that the BB happened in between us, and that galaxy?
If we look at galaxies diametrically opposite the GNZ11 from our perspective, are they moving less quickly away from us because we and they are moving away from the BB site in the same direction?
And, and, this Cosmic Microwave Background Radiation, said to be an echo of the BB, why hadn’t it overtaken us and vanished by now? Radiation must travel faster than galaxies. If I am a duck on a pond and someone throws a pebble in, the ripples radiate out and go past me. They don’t hang around to be measured years later.
Thanks.
I like questions like these.If we look at galaxies diametrically opposite the GNZ11 from our perspective, are they moving less quickly away from us because we and they are moving away from the BB site in the same direction?
And, and, this Cosmic Microwave Background Radiation, said to be an echo of the BB, why hadn’t it overtaken us and vanished by now? Radiation must travel faster than galaxies. If I am a duck on a pond and someone throws a pebble in, the ripples radiate out and go past me. They don’t hang around to be measured years later.
Thanks.
I think the first thing to start off with is that science doesn't really know many of the details regarding the origins of the universe, it uses a number of theoretical models based on following various equations to their limits.
And that is often where existing theories/models break down to meaningless or pure fantastical philosophical thinkings.
To get a handle of what is the "universe" you have to think of it as "everything". Something with no boundary, because all the maths in use on this scale uses the fact that the universe is 'flat' and infinite in size.
So with that in mind, there is no single point within the universe that could ever be considered as "the geometric centre".
All we have is our "Visible part of the universe" which, if the entire universe is infinite in size, means that our visible part is nothing special. It is in fact just a minutely small part of a vast infinite entity.
The maths models used to describe the universe can only state that the entire universe is a MINIMUM of 500 times bigger than the visible part that we have been able to observe. The MINIMUM size is just that, a minimum based up on an error factor of measurement with spacetime and its 'curvature', which was found to be more or less 'flat'. As it is 'flat' then the derivation of the maths states that is can be no less than 500 times that of the visible universe, but without the ability to refine he margin of error the theories consider the universe to be infinite.
So, with an infinite space, by compressing everything close together, you will notice that you still have an infinite space.
Compress it more and more and the space is still infinite in size. There is no edge which comes closer to another edge.
All that is happening is that the 'fabric' of space-time is close together and that matter within it is close together.
The theory states that the size of our visible universe when time was only a fraction of a second was a size less than an atom (using today's measurements).
But then all that means is tha everywhere within an infinite sized universe was also similarly dense with matter. Not that somehow there were edges of the universe that has become close together.
The "big bang" element more describes the rapid inflation of space that separated 'mass' , which is called the "inflation theory" and which happened over a fraction of a second.
This rapid inflation/separation of 'mass' and space happend way faster than the speed at which light can travel. Way way faster.
As such it placed mass way beyond the point at which electro-magnetic waves originated, but at the same time it cause electromagnetic waves to occur everywhere within the area of expansion/inflation, which again was everywhere in the infinite universe.
So after inflation the CMB radiates out in all directions and radiates throughout the inflated space, whereby over 14 or so billion years it is still being received in all directions by all points in the universe.
The CMB that would have occurred in our local part of the universe left us long ago at the speed of light. But we are receiving CMB from all other parts of the universe as the EM radiation catches up with us over time.
So to summarise, the BB happened everywhere as there is no 'centre' of an infinite sized space. The BB was the 'inflation' part of the theory, the small fraction of a second that everything everywhere experienced a rapid increase of space between everything else. From the size of an atom to the size of the early star forming universe - which remember was still infinite in size, just that the space between everything was smaller.
Edited by GroundZero on Thursday 22 October 09:56
Great, cheers.
A follow-up. We hear that prior to Big Bang the entire universe existed in a dense body smaller than an atom.
Why does it have to be so small? Why cannot it have been say apple-sized, basketball sized or planet-sized, which would also make it unbelievably dense, but more analogous to a super black hole.
A follow-up. We hear that prior to Big Bang the entire universe existed in a dense body smaller than an atom.
Why does it have to be so small? Why cannot it have been say apple-sized, basketball sized or planet-sized, which would also make it unbelievably dense, but more analogous to a super black hole.
Ayahuasca said:
Great, cheers.
A follow-up. We hear that prior to Big Bang the entire universe existed in a dense body smaller than an atom.
Why does it have to be so small? Why cannot it have been say apple-sized, basketball sized or planet-sized, which would also make it unbelievably dense, but more analogous to a super black hole.
Not quite the case. The current observable universe back close to t=0 was less that the size of an atom, using today's measurements, but the entire universe was still infinite in size, using any measurements.A follow-up. We hear that prior to Big Bang the entire universe existed in a dense body smaller than an atom.
Why does it have to be so small? Why cannot it have been say apple-sized, basketball sized or planet-sized, which would also make it unbelievably dense, but more analogous to a super black hole.
It is described as that small due to the way the theory extrapolates backward by running the maths backwards in terms of current observables such as expansion/CMB & red-shift etc. The theory states that the universe is expending and as such was once 'closer' and more compact that it is today. Running that backwards leads to a point whereby everything, in terms of matter and energy occupied the same compact spaces.
But remembering the nature of 'infinity' , it still means the universe was infinite in size, albeit with matter/energy compacted together.
Under those early universe conditions much of the theory and maths breaks down and it then becomes a game of philosophy to gain an idea of what was happening.
Also under those early conditions the laws of physics are unknown by any of our maths. So black holes and current observable entities within the current universe may not have been possible.
I've also wondered why the early universe wouldn't be an infinite sized black hole, but then a black hole requires a singularity, or a centre, which is impossible in an infinitely sized space.
Just to add as a further aid : The big-bang is often mis-described by many and leaves people to think there must have been a 0,0 point in which it all originated from.
On doing some casual reading on some other related subjects I saw a couple of well used diagrams that may help, as the hold saying goes, "a picture paints a thousand words"....
Diagram 1:
http://www.untpikapps.com/wp-content/uploads/2018/...
Diagram 2:
https://upload.wikimedia.org/wikipedia/commons/e/e...
(#1) is the misleading image I find. It suggests an origin point.
(#2) is better version to describe the observable universe. Note that at the edges things are closer together, which is intentional to show the universe as it was (as observed) and also 'extrapolated' backwards towards the "red-line" boundary which in this image I presume is the point at which photons were 'released' and which produces the CMB that we see coming from everywhere.
Note how in every direction from our centre point the extents of the image are more condensed. That should hopefully go a long way to show 'visually' how in every direction space/time were more condensed the further away we observe. The further away we observe the further back in time we observe. So with every direction showing a condensed state it shows there is no centre of the universe. There is no 'origin' of the big bang. Because when it occurred, the big bang was the universe and it was 'everywhere'. It was likely infinite in size then as it is likely infinite in size now. But infinity is the key, it literally means no edge, no centre.
On doing some casual reading on some other related subjects I saw a couple of well used diagrams that may help, as the hold saying goes, "a picture paints a thousand words"....
Diagram 1:
http://www.untpikapps.com/wp-content/uploads/2018/...
Diagram 2:
https://upload.wikimedia.org/wikipedia/commons/e/e...
(#1) is the misleading image I find. It suggests an origin point.
(#2) is better version to describe the observable universe. Note that at the edges things are closer together, which is intentional to show the universe as it was (as observed) and also 'extrapolated' backwards towards the "red-line" boundary which in this image I presume is the point at which photons were 'released' and which produces the CMB that we see coming from everywhere.
Note how in every direction from our centre point the extents of the image are more condensed. That should hopefully go a long way to show 'visually' how in every direction space/time were more condensed the further away we observe. The further away we observe the further back in time we observe. So with every direction showing a condensed state it shows there is no centre of the universe. There is no 'origin' of the big bang. Because when it occurred, the big bang was the universe and it was 'everywhere'. It was likely infinite in size then as it is likely infinite in size now. But infinity is the key, it literally means no edge, no centre.
Edited by GroundZero on Friday 6th November 14:40
Ayahuasca said:
Forgive my non-physicist questions on this, but we keep hearing that before the BB the universe was compressed into a tiny area. Where was that area? If we can observe galaxy GNZ11 13.8 billion light years away, and that galaxy was formed relatively shortly after BB, and the light from that galaxy is red-shifted, so it is travelling away from us, and presumably also away from the site of the BB, does that mean that the BB happened in between us, and that galaxy?
If we look at galaxies diametrically opposite the GNZ11 from our perspective, are they moving less quickly away from us because we and they are moving away from the BB site in the same direction?
And, and, this Cosmic Microwave Background Radiation, said to be an echo of the BB, why hadn’t it overtaken us and vanished by now? Radiation must travel faster than galaxies. If I am a duck on a pond and someone throws a pebble in, the ripples radiate out and go past me. They don’t hang around to be measured years later.
Thanks.
There wasn't a "before the big bang", time started at the point of the big bangIf we look at galaxies diametrically opposite the GNZ11 from our perspective, are they moving less quickly away from us because we and they are moving away from the BB site in the same direction?
And, and, this Cosmic Microwave Background Radiation, said to be an echo of the BB, why hadn’t it overtaken us and vanished by now? Radiation must travel faster than galaxies. If I am a duck on a pond and someone throws a pebble in, the ripples radiate out and go past me. They don’t hang around to be measured years later.
Thanks.
MiseryStreak said:
It’s described beautifully by my favourite physics author Carlo Rovelli, in his book The Order of Time. His earlier book, Reality is Not What it Seems, is one of my all time favourite books.
Yeah - 'Reality...' is certainly up there on my list too - challenging enough for a layman without being inaccessible gobdly-gook with a great arc of story embedded throughout. Maybe due to my limited capacities but after reading as much as I can until I butt against incomprehension on the other theories [string, pilot wave etc] this one seems graspable and 'sensible'. Which means it is probably wrong and I've misunderstood it anyway.ash73 said:
That picture reminds me of Penrose's Angels and Devils (or rather Escher's). Well worth watching his presentation on YT, if you really want to blow your mind.
His interview with Joe Rogan was surprisingly good, too.
I tend to think of the universe being like a mathematical fractal; both finite and infinite because it's instantiated at whatever level you observe. Anything else would be ridiculously inefficient.
It’s the same projection of hyperbolic geometry onto a plane.His interview with Joe Rogan was surprisingly good, too.
I tend to think of the universe being like a mathematical fractal; both finite and infinite because it's instantiated at whatever level you observe. Anything else would be ridiculously inefficient.
Ayahuasca said:
Forgive my non-physicist questions on this, but we keep hearing that before the BB the universe was compressed into a tiny area. Where was that area? If we can observe galaxy GNZ11 13.8 billion light years away, and that galaxy was formed relatively shortly after BB, and the light from that galaxy is red-shifted, so it is travelling away from us, and presumably also away from the site of the BB, does that mean that the BB happened in between us, and that galaxy?
If we look at galaxies diametrically opposite the GNZ11 from our perspective, are they moving less quickly away from us because we and they are moving away from the BB site in the same direction?
And, and, this Cosmic Microwave Background Radiation, said to be an echo of the BB, why hadn’t it overtaken us and vanished by now? Radiation must travel faster than galaxies. If I am a duck on a pond and someone throws a pebble in, the ripples radiate out and go past me. They don’t hang around to be measured years later.
Thanks.
(edited for accuracy)If we look at galaxies diametrically opposite the GNZ11 from our perspective, are they moving less quickly away from us because we and they are moving away from the BB site in the same direction?
And, and, this Cosmic Microwave Background Radiation, said to be an echo of the BB, why hadn’t it overtaken us and vanished by now? Radiation must travel faster than galaxies. If I am a duck on a pond and someone throws a pebble in, the ripples radiate out and go past me. They don’t hang around to be measured years later.
Thanks.
In Roger Penrose's Conformal Cyclic Cosmology (CCC) theory there isn't actually a beginning; a new universe is automatically created when all matter in an expanding universe has decayed into massless particles. Some theories predict protons are unstable, in which case you'd have to wait something like 10^32 years, or if they are not you'd have to wait a bit longer for quantum-mechanical effects such as tunneling to achieve the same - something like 10^(10^75)) years. Matt Dowden has a really good video on this: https://www.youtube.com/watch?v=3tCWWnXicC0
The point is that if there are only massless particles (traveling at the speed of light), then the whole concept of space and time disappears. That is because essentially particles traveling at the speed of light complete their entire journey from start to destination in precisely zero time, and are experiencing precisely zero spatial dimensions. You could say that photons do not experience our familiar 4-dimensional spacetime at all. As there are no longer any yardsticks, or clocks, in the universe, it "resets" to zero size (still containing all the energy of the massless particles): a new Big Bang. There is a Wiki on CCC here: https://en.wikipedia.org/wiki/Conformal_cyclic_cos...
To me the most interesting part is that it automatically explains the brief era of inflation - a problem for which there isn't otherwise a solution: inflation is merely the long expansion (up to 10^(10^75) years) of the previous universe. Research is ongoing to try to detect remnants in the Cosmic Background Radiation, for example from exploding super-massive black holes (or even signals from intelligent life in the previous cycle). Another excellent video by Matt Dowden on this topic: https://www.youtube.com/watch?v=PC2JOQ7z5L0
Fascinating stuff
Edited by Jim1064 on Saturday 26th December 12:18
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