Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Can we see the big bang?

  1. May 20, 2006 #1
    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.
     
  2. jcsd
  3. May 20, 2006 #2

    Pengwuino

    User Avatar
    Gold Member

    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
     
  4. May 20, 2006 #3
    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.
     
    Last edited: May 20, 2006
  5. May 20, 2006 #4

    Pengwuino

    User Avatar
    Gold Member

    But space-time has expanded away from the big bang, if you're looking through a telescope, you're looking at a distance.
     
  6. May 20, 2006 #5

    SpaceTiger

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    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.
     
  7. May 20, 2006 #6
    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?
     
  8. May 20, 2006 #7

    SpaceTiger

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    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.
     
  9. May 20, 2006 #8
    it is the theory of big bang true?i don belife that.
     
  10. May 20, 2006 #9

    Garth

    User Avatar
    Science Advisor
    Gold Member

    Do you understand the reasons why other peole do?

    Garth
     
  11. May 21, 2006 #10

    Chronos

    User Avatar
    Science Advisor
    Gold Member
    2015 Award

    Feel free to believe whatever it is you believe, thoms. Ignoring science does not make it go away . . . drat, Garth already said that.
     
    Last edited: May 21, 2006
  12. May 21, 2006 #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.
     
  13. May 21, 2006 #12

    EL

    User Avatar
    Science Advisor

    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.

     
    Last edited: May 21, 2006
  14. May 21, 2006 #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:
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Can we see the big bang?
  1. How can we see Big Bang? (Replies: 11)

Loading...