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

B Where is all the Energy?

  1. Nov 18, 2016 #1
    Is all of the energy produced by the big bang still around? According to the law of energy conservation it should be right? is it all packed into regular matter? what kind of role does dark energy have to do with this?
     
  2. jcsd
  3. Nov 18, 2016 #2
    Yes all the energy present at the big bang should still be in the Universe in some form or another.
    Some of it is in the form of regular matter (and radiation).
    Dark matter and dark energy represent the rest of it, but we are still a long way from understanding what those are.
     
  4. Nov 18, 2016 #3

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    There are various versions of this chart around..

    planck.jpg
     
  5. Nov 18, 2016 #4
    That doesn't work in an expanding univers.
     
  6. Nov 18, 2016 #5
    Well based on this picture, why is most of the energy and matter in the universe dark? if there is a antiparticle or each regular particle and some particles are their own antiparticles, should there be a even number?
     
  7. Nov 18, 2016 #6
    Antimatter still is 'ordinary' matter, not dark matter, but the particles have opposite charges.
    If matter and antimatter meet they should annihilate each other leaving nothing but radiation.
    Dark matter on the other hand does not interact with ordinary matter, except through gravity.
    The big puzzle here is why the big bang could produce an excess of the ordinary matter which the world is eventually made of,
    and less of it's antimatter equivalent.
     
    Last edited: Nov 18, 2016
  8. Nov 18, 2016 #7

    Drakkith

    User Avatar

    Staff: Mentor

    That is one of the great unsolved mysteries in cosmology and particle physics. We simply don't know.
     
  9. Nov 19, 2016 #8

    Chalnoth

    User Avatar
    Science Advisor

    Energy isn't conserved in an expanding universe.

    See here for one explanation:
    http://www.preposterousuniverse.com/blog/2010/02/22/energy-is-not-conserved/
     
  10. Dec 27, 2016 #9
    Appreciate your honesty. I find some scientists have a difficult time admitting they don't really know.
     
  11. Dec 27, 2016 #10
    Love your honesty and humility!
     
  12. Dec 27, 2016 #11

    Chalnoth

    User Avatar
    Science Advisor

    That's usually not a problem you find among scientists. Scientists spend a lot of time examining precisely how much we do and do not know. If anything, scientists tend to be more tentative about expressing certainty than they need to be.
     
  13. Dec 28, 2016 #12

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    We rely on best fit models, unfortunately, best fit does not always mean best sense. Get used to it.
     
  14. Dec 29, 2016 #13
    I tend to not believe that, most scientists are much more careful about saying what they do know. Theory either fits observation or it doesn't, or one of them doesn't exist yet. The term "dark" means we don't know.

    The Higgs boson is a good example. It was always called a theoretical particle until it was found, even though most scientists believed it was there. All the calculations required it. That wasn't like dark matter. Dark energy and matter came from observations.

    Science IS the boundary between what's known and what isn't.
     
  15. Dec 30, 2016 #14

    Chalnoth

    User Avatar
    Science Advisor

    Pedantic rant:

    It's actually not the best-fit models, for the simple reason that it is always possible to add parameters to a model to improve the fit, even if those parameters aren't realistic. There is a balance between goodness-of-fit and the number of parameters in the model (there may also be other considerations that are relevant as well, such as whether the model is mathematically sound). Unfortunately, there's no unambiguous way to strike that balance. So physicists usually try to err on the side of caution and require large amounts of evidence before saying that one model is clearly superior to another.
     
  16. Dec 31, 2016 #15
    True, it's coming up with those parameters that takes genius. Sometimes they're really weird, like the concept that space itself bends or that energy is quantized.
     
  17. Jan 5, 2017 #16

    Chronos

    User Avatar
    Science Advisor
    Gold Member

    Chalnoth, it's unclear if you are opposing logic, best fits, or both? My point is logical models are not always best fits, but, best fit models are not always logical. Science generally demands any model be logically consistent.
     
    Last edited: Jan 5, 2017
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Where is all the Energy?
  1. Where does energy go (Replies: 3)

Loading...