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Will the James Webb telescope see past the big bang?

  1. Dec 2, 2013 #1
    Will the James Webb telescope be able to see beyond the Big Bang in principal? I realize, in reality this is not possible, but I'm curious if it will see as far back as possible, or if the telescope has limits, and eventually we will need a better telescope to truly look deep. Thanks!
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  3. Dec 2, 2013 #2


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    The radiation in the electromagnetic spectrum did not propagate more than a tiny amount in the early universe. Google "surface of last scattering". NOTHING will ever be able to see EM radiation further back than that (about 400,000 years AFTER the big bang singularity). I think, and I'm sure more knowledgeable folks will jump in here if I'm wrong, that a couple of possible ways to see past it, because they do not involve EM radiation, are gravity waves and neutrinos, but these methods are speculative.

    The concept of seeing "past" the big bang is nonsense according to current cosmology theory, since there WASN'T anything prior to the big bang.
  4. Dec 2, 2013 #3
    Right. I figured that was the case. I am curious though... Will the James Webb Telescope be able to see up to this point clearly? Or do we need a yet, even more powerful, telescope. Thanks!
  5. Dec 2, 2013 #4


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    That will depend on whether or not it "sees" in the microwave region of the spectrum since that's where the CMB currently is. If it is looking for things in the visible range of the spectrum then it will be totally blind to the CMB.

    EDIT: I just did a quick check on that telescope. It is not even remotely intended to look at the CMB, it is intended to look at the earliest formations of cosmological objects (planets, galaxies, etc), all of which happened many millions of years after the surface of last scattering (and possibly as much as a billion or more) so the Webb telescope won't be going back anywhere near the creation of the CMB
    Last edited: Dec 2, 2013
  6. Dec 2, 2013 #5
    Do we believe it will see the very earliest objects? I wonder if it will see an epoch of darkness in the background. Perhaps a more powerful telescope is needed. Admittedly, I've become very excited to see this technology in it's orbit out in space. Thank you.
  7. Dec 3, 2013 #6


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    The JWT will probably see back to the first galaxies, and possibly pop I stars - an impressive achievement
  8. Dec 3, 2013 #7
    The Cmb was emitted 380k years after the big bang. Before that the universe was much like the surface of the sun i.e opaque. You cant see the interior of the sun just like you can't see before the Cmb was emitted with Em radiation.
    So getting a bigger better telescope isn't going to help.

    However all is not lost. First off by studying the CMB it may be possible to infer indirectly what happened in much earlier epochs. The next big I think will be better polarisation maps of the CMB. Planck will give us this next year.
    Beyond that there are other ways to see to earlier times. One is with neutrinos and the other is with gravitational waves. Primordial neutrinos and gravity waves are very hard to detect and my guess is its decades away. But I'd love to be proven wrong on that.
  9. Dec 3, 2013 #8


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    JWST looks in the infrared, and so won't see much of the CMB at all (which is today at significantly lower frequencies). It will be able to look at many of the earliest-formed galaxies, but not anything before galaxies formed. The Planck telescope is currently our best picture of the earliest stage of the universe we can see with electromagnetic radiation.
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