What Could We See If We Observed the Big Bang with a Powerful Telescope?

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Discussion Overview

The discussion revolves around the implications of observing the Big Bang with a powerful telescope, specifically what one might see if looking back 14 billion light years. Participants explore concepts related to the Big Bang theory, the nature of singularities, and the limitations of observing early universe phenomena.

Discussion Character

  • Exploratory
  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether a telescope could reveal a singularity at the Big Bang, suggesting that it should only show nothing.
  • Another argues that due to the expansion of space-time, observing the Big Bang would not be straightforward, as one is looking at distances rather than a singular point.
  • A participant notes that if one could travel faster than light, observing the singularity might be feasible, but emphasizes that their original question did not involve movement.
  • Discussion includes the idea that light from the Big Bang would be redshifted to a point where it is no longer observable, with a reference to the surface of last scattering.
  • Some participants express confusion about the limits of observation, particularly regarding the density and ionization of matter in the early universe affecting light travel.
  • There are assertions about the Big Bang theory being a well-supported scientific theory, with references to observational evidence such as cosmic microwave background radiation and the abundance of light elements.
  • One participant challenges the validity of the Big Bang theory, expressing disbelief and questioning the reasons others accept it.
  • Another participant counters that while the Big Bang is a theory, it is supported by strong observational evidence and is not merely a guess.
  • There is a mention of differing views on the number of pillars supporting the Big Bang theory, with one participant suggesting four instead of three.

Areas of Agreement / Disagreement

Participants express a range of views on the Big Bang theory, with some supporting it based on observational evidence while others express skepticism. The discussion remains unresolved regarding the nature of what could be observed if one were to look back to the Big Bang.

Contextual Notes

Limitations include the dependence on definitions of singularities and the effects of redshift on light from the early universe. There are also unresolved questions about the implications of density and ionization on light travel in the early universe.

Abbas Ibn Firnas
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Hi,

I have a question...

If I were to build a telescope that could produce images of things about say... 14 billion light years away... What would I see?

According to the Big bang theory, shouldn't I just see a singularity and nothing else?

Thanks.
 
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No, that's like saying if you run across the street, you can use a pair of binoculars to look at yourself on the other side of the street
 
actually... if I could travel faster than light, that wouldn't be so difficult.

Anyway, my question didn't involve moving anywhere, and so your answer was not relevant.
 
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But space-time has expanded away from the big bang, if you're looking through a telescope, you're looking at a distance.
 
Abbas Ibn Firnas said:
According to the Big bang theory, shouldn't I just see a singularity and nothing else?

There probably won't actually be a singularity (see the many discussions on quantum gravity in this and the "Beyond the SM" forum), but in traditional BB theory, the singularity would lie at z=infinity, so its light would be redshifted to nothing. It doesn't matter, though, because in practice we can't observe light beyond the surface of last scattering at z=1100.
 
Thanks for your reply.

I don't really know much about physics so that just went right over my head. Are you saying there's some kind of limit at which the light moving away from the big bang no longer reaches us?
 
Abbas Ibn Firnas said:
I don't really know much about physics so that just went right over my head. Are you saying there's some kind of limit at which the light moving away from the big bang no longer reaches us?

At earlier times in the history of the universe, the matter was much denser and more ionized, so light couldn't travel very far through it before getting absorbed/scattered. It wasn't until about 300,000 years after the Big Bang that light could travel long distances without interacting with matter. Thus, virtually all of the light that we see was emitted after the universe was ~300,000 years old. The rest has long since been absorbed/scattered.
 
it is the theory of big bang true?i don belife that.
 
thoms2543 said:
it is the theory of big bang true?i don belife that.
Do you understand the reasons why other peole do?

Garth
 
  • #10
Feel free to believe whatever it is you believe, thoms. Ignoring science does not make it go away . . . drat, Garth already said that.
 
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  • #11
measure the age of universe?can we?can we measure the number of sand of a big river?otherwise big bang is a theory, it does not mean that it is true at all.
 
  • #12
thoms2543 said:
otherwise big bang is a theory

Sure it's a theory (what else could it be?). But it's definitely not a guess.
Big Bang theory is suported by a number of strong observations, see e.g. http://en.wikipedia.org/wiki/Big_bang#Observational_evidence.

wikipedia said:
It is generally stated that there are three observational pillars that support the Big Bang theory of cosmology. These are the Hubble-type expansion seen in the redshifts of galaxies, the detailed measurements of the cosmic microwave background, and the abundance of light elements. (See Big Bang nucleosynthesis.) Additionally, the observed correlation function of large-scale structure of the cosmos fits well with standard Big Bang theory.
 
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  • #13
Well, I would say there were 4 pillars that support the standard big bang theory (lambda CDM) and they include those mentioned in the Wikepedia article, plus large hierarchical scale structure observations, but I am biased! :biggrin:
 

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