Comments by "N Marbletoe" (@nmarbletoe8210) on "Brian Cox - Is The Big Bang Theory Wrong?" video.

  1. Any light that was emitted before the CMB at ~ 380,000 years of age would not be visible today, as it has collided with ions in the plasma that existed before that time.
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  2. The simple inference is that structure formation had some kind of a kickstart in the early universe. One way is if like you say, the universe did not start at the bang, and some material from before persists through the bang, a-la Penrose's CCC theory. Another way would be to have some kind of "sticky" dark matter. In any case it looks like the LCDM model is being challenged big time! This is not the only observation to do so. Giant voids apparently are too big for the model. No expert here, but it is cool to see doors open to new theories!
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  3.  @Batters56  yup, but to be clear it didn't happen instantly. 380,000 years is the time when ~ 90% of the plasma had combined into atoms and become transparent.
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  4.  @cifey  yes. a photon could only travel a short distance before hitting a plasma ion and being absorbed or deflected. it would have been like a luminous thick fog
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  5. the origin is in all directions in space, but one direction in time.
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  6. yes!
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  7. The origin is one. The center is everywhere, but not every-when.
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  8. Susskind said he uses "Big Bang" to mean the end of inflation. That would make it hot, and it would also mean that it was not the very beginning. That is essentially a matter of terminology. Inflation wasn't yet a concept when Lematre came up with the big bang.
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  9.  @loki76  Yes, for sure the universe could be infinite in age, or it could be finite but much older than 13.8 if it cycles for example. Some theories of infinite age include Eternal Inflation (Susskind has a great talk on this) and Penrose's CCC. I'd say the 380,000 is a calculation that rests on assumptions. The assumptions would be the entire L-CDM model, I suppose. Soon there will be ways to see further than the CMB with neutrinos and gravit waves. Penrose even proposes that gravity waves from the previous universe are affecting the universe today! The L-CDM model will probably change at least a little due to discoveries of early structure formation and the size of giant voids which are "too big." It'd sure help to know what dark matter is actually.
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  10.  @elingeniero9117  Inside a plasma, light is emitted and absorbed constantly, with no photon getting very far.
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  11.  @elingeniero9117  The distance a typical photon travels in a gas is called the "mean free path" of the photon. For the CMB the mean free path of photons was very short, comparable to the distance between atoms.
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  12.  @elingeniero9117  You may be thinking of a very early time in the universe. The CMB's 'surface of last scattering' was hundreds of thousands of years after the big bang and things had cooled to just a few thousand K. To quote Physics Stack Exchange, "The universe was a thermal plasma prior to the recombination epoch..."
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  13. hundreds of millions
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  14.  @MemekingJag  I want to point it at my house and see where my cat goes.
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  15. Occam would say lazy is good
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  16. or Cygnus X-1?
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  17. i think you are in fact correct. The resolution is to specify that there is an expansive factor everywhere. This factor can easily be countered for short distances. This would be a more precise way of describing cosmic expansion. Good show
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  18. ?? Where a light has disappeared would show nothing at all. There's no light, so no image, no glow.
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  19. Yes, God did it. He made the bang, and He made it big. The JWST was never designed to look all the way back, which is an actual impossibility for a light-based telescope.
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  20. yes, and yes
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  21. The term "right" is a bit squirrelly. It really does not apply to science in an absolute sence.
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  22.  Greg LeJacques  Indeed! I didn't know that term before, but it's why I'm Unitarian Universalist. They got the juice without the noose. There are even UU folks who are atheist.
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  23.  Greg LeJacques  Hey that is an interesting take! 'all is made from arbitrary symbol' thanks i will ponder that
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  24. don't forget about time
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  25. Yes, but no. It is impossible to prove, but one can do far better than speculate.
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  26. Testable guess, but not necessarily best guess
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  27. When we know more, we can name it. Like some cultures only name a baby after the age of 1.
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  28. It's what you need to fill the Big Bong
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  29. unknown
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  30.  @goodgood9955  I watched a talk by Susskind, he said that vacuum energy "should" cause expansion, according to theory. However, the predicted expansion is 120 orders of magnitude too large. So, they really do not know what is causing it!
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