One quibble though... why do you keep calling the Big Bang 'The Big Bounce'?
There's no evidence for the idea that the Bang was actually a Bounce (i.e., that our Universe was preceded by another Universe, contracting under gravity until it collapsed in a Big Crunch, which then bounced producing our hot Big Bang). It's not even a particularly mainstream view in cosmology these days.
We know the Big Bang happened (i.e., that 13.8 billion years ago the whole Universe was very hot and dense, and it rapidly expanded and cooled becoming the Universe we see around us). Any theories about what came before -- eternal inflation or a Bounce -- must be taken as speculative until there is any evidence for them, surely?
Penrose has been saying this for years, but no evidence has ever turned up. Around 2010 or so Penrose was 100% certain there would be evidence in the Planck CMB data. I'm a cosmologist -- I was just finishing my PhD at the time, and I spoke to Penrose about it when he came to give a lecture at my home institution. He was so certain that the first Planck data release in 2011 was going to be a slam dunk for him.
But nothing turned up! 15 years later, there's no hint of a Bounce in the best CMB data we have.
It's not like inflation (which has no evidence yet, but the theory is needed to explain some anomalous facts about our Universe). The Bounce isn't needed to explain anything, and there's no evidence for it. It's not been ruled out (absence of evidence and all that). But the theory has basically fallen by the wayside at this point. There's no motivation for believing it, apart from a philosophical prior.
I am thrilled to have you as a reader. I take a different tack though. The infinities and inflation of BB are just too much for me. In my later posts I therefore explore the milder bounces of black holes. In general, I don’t think the first split second of BB needs to be accepted. It is magnificent thereafter.
Thanks for writing this beautiful and engaging piece, Hans. The scale of the universe, from the muons and gluons to the furthest edge of the Big Bang (is there one? another mid-boggling question) is truly astounding. I, for one, am grateful to be a witness to it. As I know you are!
My suspicion is that the enormity of space is something like an illusion, like a set of rules, a hierarchy of what interacts when. Entanglement can perhaps be seen as an indication how to break these rules. Accordingly for some aspects the universe appears tiny and within almost immediate access. David Bohm’s “Implicate Order” may be on to something; it suggests that the observed world reflects a yet more basic one. Does that resonate with your Zen views, Mike?
I found that an underlining was dropped through translation into substack in the following sentence: “is denoted as ten to the power 15 or p15 (it can alternatively be written as 15).” The last entry 15 was meant to be underlined. Sorry.
Great article!
One quibble though... why do you keep calling the Big Bang 'The Big Bounce'?
There's no evidence for the idea that the Bang was actually a Bounce (i.e., that our Universe was preceded by another Universe, contracting under gravity until it collapsed in a Big Crunch, which then bounced producing our hot Big Bang). It's not even a particularly mainstream view in cosmology these days.
We know the Big Bang happened (i.e., that 13.8 billion years ago the whole Universe was very hot and dense, and it rapidly expanded and cooled becoming the Universe we see around us). Any theories about what came before -- eternal inflation or a Bounce -- must be taken as speculative until there is any evidence for them, surely?
Famous people like Penrose think there was something before!
Penrose has been saying this for years, but no evidence has ever turned up. Around 2010 or so Penrose was 100% certain there would be evidence in the Planck CMB data. I'm a cosmologist -- I was just finishing my PhD at the time, and I spoke to Penrose about it when he came to give a lecture at my home institution. He was so certain that the first Planck data release in 2011 was going to be a slam dunk for him.
But nothing turned up! 15 years later, there's no hint of a Bounce in the best CMB data we have.
It's not like inflation (which has no evidence yet, but the theory is needed to explain some anomalous facts about our Universe). The Bounce isn't needed to explain anything, and there's no evidence for it. It's not been ruled out (absence of evidence and all that). But the theory has basically fallen by the wayside at this point. There's no motivation for believing it, apart from a philosophical prior.
I am thrilled to have you as a reader. I take a different tack though. The infinities and inflation of BB are just too much for me. In my later posts I therefore explore the milder bounces of black holes. In general, I don’t think the first split second of BB needs to be accepted. It is magnificent thereafter.
Thanks for writing this beautiful and engaging piece, Hans. The scale of the universe, from the muons and gluons to the furthest edge of the Big Bang (is there one? another mid-boggling question) is truly astounding. I, for one, am grateful to be a witness to it. As I know you are!
Michael Smith, Bozeman, MT
My suspicion is that the enormity of space is something like an illusion, like a set of rules, a hierarchy of what interacts when. Entanglement can perhaps be seen as an indication how to break these rules. Accordingly for some aspects the universe appears tiny and within almost immediate access. David Bohm’s “Implicate Order” may be on to something; it suggests that the observed world reflects a yet more basic one. Does that resonate with your Zen views, Mike?
Yes, it does Hans. I do not know anything about "implicate order", so will have to read up on it. Thanks for sharing and asking!
I found that an underlining was dropped through translation into substack in the following sentence: “is denoted as ten to the power 15 or p15 (it can alternatively be written as 15).” The last entry 15 was meant to be underlined. Sorry.