False and True Vacuums

Discussion in 'Physics & Math' started by BobG, Jun 5, 2002.

  1. BobG Registered Senior Member

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    I found this whilst reading "The Last Three Minutes" by Paul Davies somethin about two different kinds of vacuum.

    I thought Vacuums were just areas with no matter or energy but I read somewhere about true vacuums and false vacuums which are so called "excited vacuums". I'm not sure of the relevance of this but it also said there is a small chance of the universe being in a false vacuum, in which case if a true vacuum bubble is made it could in fact destroy the universe.

    It then goes on to say there is a chance in the future that Particle accelerators have a small chance of setting it off.

    Does anyone have any information on this as you can see I don't fully understand.
     
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  3. thed IT Gopher Registered Senior Member

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    BobG

    This is gory stuff at the leading edge of Physics. If you can, get hold of The Inflationary Universe by Alan H. Guth. The concept of 'false vacuums' lies at the heart of Guth's new Inflationary model of the Big Bang.

    It works like this. The vacuum is traditionally seen as an absence of matter that is not very interesting. What Guth done was borrowed an idea from Higgs where particle interactions involve the use of a quantum scalar field, called the Higgs Field. In english it means that each point in space is suffused with a 'field' that has no direction (a value only) and is quantised, it takes discrete values. This is as oposed to quantum vector and gauge fields. (To be honest this is on the limit of my knowledge and understanding as well).

    In the lowest energy state this 'Higgs Field' is what we see as the vacuum. In the early Universe, the first billionths of a second, the total energy of the Universe was compressed into a very small space. This meant the Higgs Field was very energetic. If for some reason one part of the field drops to a lower energy state it will have a 'negative energy' compared to what's round it. In General Relativity this corresponds to a negative pressure and hence a 'anti-gravity' affect. This drop in energy is called spontaneous symmetry breaking. A known effect where something changes state quickly caused by a small, almost insignificant, change elsewhere.

    In short, the Universe expands massively and very quickly. This also causes it to drop into a lower energy state.

    There is an outside chance that the current vacuum is not in it's lowest energy state and could still drop to a lower energy state. If this idea is right then that would cause another expansion event, effectively causing Universe to change state. In other words, life as we know would cease.

    If anyone else has a better understanding of this I'd be interested in hearing it.
     
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  5. BobG Registered Senior Member

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    Thanks that helps a lot
     
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  7. thed IT Gopher Registered Senior Member

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    bob

    Glad you understood it. As I say, this is on the limit of my knowledge. It's way hairy stuff.
     
  8. huh??? Registered Senior Member

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    Check out Alan Guth's "<I>The Inflationary Universe</I>"

    If only we could harness their power...

    Though I don't really know what they are, I think they have something to do with the casimir effect. In 10<SUP>-34</SUP> of a second, an area less than a billionth the size of a proton became an extremely energetic "marble", equivalent to a pea growing to the size of the milky way (Discover, April, 2002). To give you an idea of how energetic, this marble contained all of the matter and energy of the universe, and STILL overcame gravity. There was also something in popular science feb 2002 (I think) unscrambler where this false vacuum could cause our demize, but it depends on supersymetry and all kinds of complicated stuff like that. Basically, it may be responsible for the accellerating universe, and it may be our only hope, because without it, the universe would be finite. With it, you can get something for nothing, and the universe is most likely infinite, which means we will never run out of energy.
     
  9. thed IT Gopher Registered Senior Member

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    Huh??

    You mean this paper and this paper, as examples.

    The Casimir Effect and Inflation have little to do with each other.
     
  10. thed IT Gopher Registered Senior Member

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    They are coming to take me away, haha

    OK, I'm going to leave my last comments as examples of how damn stupid I can be

    Please Register or Log in to view the hidden image!

    note to self, engage brain before typing.

    Read the second paper, they do link the Casimir effect and inflation.

    Oh well, can't keep up with every idea being published.
     

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