World Science Scholars

3.6 Non-uniformity of the Universe

discussion Discussion
Viewing 11 reply threads
    • A lot of the discussion so far has focused on ensuring that the universe is homogeneous, which it is, on large scales. But if we look around the universe, there is a lot of evidence of inhomogeneity too (after all, the Sun is over there, and Jupiter is way over there — these are small-scale inhomogeneities). What do you think can account for these non-uniformities? (Professor Guth will answer this later in the course, but try to think of some possible explanations.)

    • When the big bang happened, Quarks were scattered across the universe by high energy photons, in order for the universe to reach thermodynamic equilibrium, these later formed elements are forced together by gravity, in order to do work, letting the universe eventually becoming completely homogenous.

    • Gravitational effects compounding small initial inhomogeneities since the Big Bang + the large absolute volume of the observable universe in which to look for
      inhomogeneities.

    • The inhomogeneities were introduced by the way of quantum fluctuations in the initial inflationary state that were then inflated during the inflationary period. These inhomogeneities then got amplified through differences in gravitational attraction in the later period of the universe and are what created the structure we currently see.

    • Robert, I think your thoughts are well taken. Prof. Guth doesn’t like to assume that the big bang was uniform but assumes that inflation was. According to Prof. Guth’s version of inflation theory, the negative gravitational field starts the period of uniform inflation. As the inflation progresses, the matter/energy making up this field randomly decays which in his words “stops the inflation” and the universe “coasts” to its present structure. The random decay must have taken place over a time period which should mean that the inflation did not stop at one time in all locations. Could this non-uniform inflation period have produced the seeds for the “clumpy matter” universe we see now? I would think that this non-uniformity as the inflation slows would be a bigger factor that the quantum uncertainty would introduce.

      • If it’s the decay of the inflaton field, probably so. If it’s the temperature variation, probably not.

    • Inhomogeneities are growing by a gravitational field. CDM is a component of our universe that makes our universe non-uniform.

    • The visible universe, in general, looks fairly uniform – however there is also a more localised clustering of matter. This could be the effect (magnified over time) of transient quantum fluctuations (the uncertainty principle?) – where stuff can have a momentary existence if it promises to disappear promptly : )

    • Quantum mechanics to the rescue…

    • Hello Ladies and Gentlemen,

      We can observe non-uniformities at different epochs.

      As historians, we understand a common beginning is possible, under CMB suggested levels. But we see at different times, the science becomes different.

      Our time has the barycentered binary of the Sun and Jupiter. In a few thousand years from now, the structure may again change.

    • Hello Ladies and Gentlemen,

      The good works of Prof. Guth and his grace to attend to WSU have made us better people.

      In finding more complete ways to fathom Big Bang theory info. Gaps, we see further that Prof. Linde and Prof. Gott have added new knowledge as new tech has brought progress.

      Astronomy is intensely under construction.

      One of the odd things about the Prof.
      Impey (ASU) expansion at fifty times the speed of light is the continual Andromena galaxy advance.

      All galaxies are in a perpetual big bang expansion of an accelerating universe, but not the Andromena galaxy, said to ruin our super massive 4 million solar mass galactic black hole with their own 104 million solar mass black hole.

      Prof. Gott shows the clustering of galaxies is predictable along filaments.

      In Gott we trust.

      So are we in a filament on a larger scale that makes it impossible for Andromena to NOT crash into us?

      Average loss on impact with blackholes is 3-5%. We are gonners when Andromena hit.

      Is there a way we can sidestep Andromena so it passes by?

      Source- Richard Gott III- book called COSMIC WEB
      🙂

    • In my mind homogenous in macro doesn’t in any way correlate to homogeneity in micro so no problem. I mean if you mix stuff together homogeneously it doesn’t have to change the stuff so you would still have differing particles in micro.

    • I see this on the large scale but there are unanswered local scale issues so far.

      • I think you hit the point. Homogeneity is probably defined in relative scale, and not a “hard defined” constant.

You must be logged in to reply to this discussion.

Send this to a friend