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Author Topic: The Big Bang and origin of dark matter ?  (Read 2200 times)

Offline Dick1038

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The Big Bang and origin of dark matter ?
« on: 26/10/2007 18:09:21 »
I read somewhere that the mathematics of quantum theory accurately predicted the percentages of hydrogen and helium created during the big bang.  Obviously, dark matter, and dark energy for that matter, had to have been created during the BB also.  The amount of dark matter dwarfs that of ordinary matter. Why isn't dark matter/energy predicted by the theory?  Is there some flaw in the theory?


Offline DoctorBeaver

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The Big Bang and origin of dark matter ?
« Reply #1 on: 26/10/2007 18:59:22 »
QT can predict the probabilities of interactions of particles. You plug in known values and QT comes up with answers that can be verified by observation. We know the abundances of Hydrogen, Helium & Lithium in the universe so any prediction made using QT can easily be verified.

But remember that physicists and cosmologists can also work in reverse, as is often the case where the evolution of the universe is concerned. They take the present state of the universe and extrapolate backwards to try to work out what the universe was like earlier in its evolution. That is how the whole Big Bang theory came about.

We extrapolate that at n seconds after the Big Bang, the state of the universe was x. After the de-coupling of energy and matter there were free-roaming particles - particles that we are now familiar with and whose properties & interactions we know. We also know the strengths of the 3 forces - electroweak, strong & gravity. Therefore, we can be confident of stating the quantities of different particles in the early universe and say that those particles would have interacted in certain ways that gave rise to the proportions of hydrogen, helium & lithium that we see today.

So, I don't think it's so much that QT predicted the abundance of the 3 primordial elements, rather that QT can be used to theorise about the early state of the universe.
« Last Edit: 26/10/2007 19:09:58 by DoctorBeaver »

Offline w65

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The Big Bang and origin of dark matter ?
« Reply #2 on: 16/01/2008 04:03:44 »
I think that perhaps dark matter was present before the big bang. It is most likely that dark matter caused the big bang.  Dark matter is as close to nothing as the universe has to offer. The flight of dark matter/energy is like a needle and thread being pulled through the fabric of the universes once the knot meets the end of the fabric it will all be pulled together collapsing on it's self and then bang number (which ever). The universe in not expanding it is actually collapsing. Dark matter/energy is simply pushing and at the same time pulling the universe back in on its self much as we see magnetic fields do on the plants and other bodies. We just can not see the horizon or boundaries of the universe and therefore we assume there are none. There have been infinite number of these cycles and will continue for eternity.... The last one will be the end of eternity. Don't worry will not happen in your life time. [^]

Offline Soul Surfer

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The Big Bang and origin of dark matter ?
« Reply #3 on: 16/01/2008 10:05:54 »
Since the formulation of the big bang it has always been known that if there was one or more particles around that only interacted by gravitiational forces they would be virtually undetectable. Astronomers were looking for the effect of the existence of such particles and detected them in the rotations and motions of galaxies on clusters they are also needed to make the galaxies form fast enough in cosmological models. 

Our particle physics experiments work mostly with charged particles electrically neutral particles are predicted and then detected with some difficulty.  Weak interaction neutral particles (neutrinos) are predicted and almost impossible to detect but this has been done.  There are several possible gravitation only particles from minimally sized black holes which gould be quite heavy to axions and sterile neutrinos which are very light.  Attempts are being made to detect them by watching for the reaction when one of them gets close to an atomic nucleus but this is extraordinarily difficult and there has been no success yet.

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The Big Bang and origin of dark matter ?
« Reply #3 on: 16/01/2008 10:05:54 »


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