What is the beggining of space time?

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SUMMARY

The discussion centers on the origins of space and time, specifically addressing the concept of singularities in the context of the Big Bang and General Relativity (GR). It is established that while the Big Bang is a widely accepted model, it primarily describes the universe's evolution post-event rather than the event itself. GR predicts that space and time are dynamic rather than fixed, and it breaks down at singularities, leaving questions about the relationship between space, time, matter, and energy unresolved. Key references include the Hawking singularity theorem and works by Ted Jacobsen and G. F. Smoot.

PREREQUISITES
  • Understanding of General Relativity (GR)
  • Familiarity with Quantum Mechanics (QM)
  • Knowledge of the Hawking singularity theorem
  • Basic concepts of cosmology and the Big Bang theory
NEXT STEPS
  • Research the implications of the Hawking singularity theorem
  • Explore the concept of emergent spacetime as discussed by Ted Jacobsen and others
  • Study the relationship between mass, energy, and gravity in GR
  • Investigate the findings of G. F. Smoot regarding cosmic background radiation
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Physicists, cosmologists, and students of theoretical physics interested in the fundamental questions surrounding the origins of space and time, as well as the implications of General Relativity and Quantum Mechanics.

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was it that singularity? what makes us so sure? what does GR predict? please be as detailed as you can and take your time if you have good information even if there are any equations. thanks in advance !
 
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was it that singularity?

yes.


what makes us so sure?

it's generally accepted...but no one is sure...maybe, for example, time is eternal...
big bang is a favorite, little bang also a possibility...Strictly speaking, the big bang model has very little to say about the big bang itself. It describes what happened afterward.


what does GR predict?

GR and QM breakdown at such singularities as big bang and black holes...useful but not a final conclusive answer. But GR posits that space and time are NOT fixed, they change and for some reason gravity is a consequence of mass, energy and pressure...says nothing about which came first.

Ultimately nobody knows what space and time are nor how they are related. Nor how they relate to matter and energy...all have "mysterious" unexplained origins...

You can read a lot of posts about spacetime on the forms here by searching Ted Jacobsen, Verlinde, Renate Loll, emergent spacetime, for a start...






please be as detailed as you can and take your time if you have good information even if there are any equations. thanks in advance !
 
In terms of classical relativity, the reason we can be sure of this is the Hawking singularity theorem: http://en.wikipedia.org/wiki/Penrose–Hawking_singularity_theorems

To check that the theorem applies to our universe, you need some observations. Here's the original paper on that: http://articles.adsabs.harvard.edu/full/1968ApJ...152...25H I believe the analysis in this paper had some holes in it, which were plugged later. More about that here: http://nobelprize.org/nobel_prizes/physics/laureates/2006/smoot-lecture.html I think this is also relevant: G. F. Smoot, M. V. Gorenstein, and R. A. Muller, "Detection of Anisotropy in the Cosmic Blackbody Radiation," Phys. Rev. Lett. 39, 898–901
 
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