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Elements of a vacuum

  1. Jul 16, 2011 #1
    Is it possible that even in a vacuum that the void space in the vacuum could consist of some other material? What is the median on which gases move, what is the nothingness in between atoms?
  2. jcsd
  3. Jul 17, 2011 #2
    The void of space, or the vacuum is full of virtual particles constantly being created and destroyed.
    That's all i can say with 100% certainty, as im here as well to try and understand more about virtual particles, and don't want to run the risk of giving you miss-information.
  4. Jul 17, 2011 #3
    Sort of a philosophical question. Since we don't have a theory of everything, we can't really say for sure. Einstein would say that it is something that can be measured using the speed of light. He would say that the distance between points and the time between events is different for every observer, but that there is a constant "distance" (called an interval) in four dimensional spacetime between all events.

    Quantum mechanics predicts that the vacuum is a soup of virtual particles, popping in and out of existence as a result of the Heisenberg uncertainty principle. Changes in the distribution of these virtual particles is what gives rise to forces like electromagnetism.

    String theory (which I don't buy into) postulates that it could be an m-brain, a four dimensional membrane that vibrating strings (subatomic particles) are stuck to.

    Other bizarre theories predict that space is an illusion and that the universe could really be a hologram existing in only two dimensions. On the microscopic scale, it may even be one dimensional.

    But really the best answer you will ever get is "I have no idea, I just know that I can measure it."
  5. Jul 17, 2011 #4
    Very interesting i had not heard of virtual particles before this. Is there a reliable source that i can go to and find information on the material of a vacuum?
  6. Jul 17, 2011 #5
    Nobody knows exactly what the "nothingness" is anymore than we know what space or time or matter is. But we do know a lot about them observationally and we have a lot of mathematics that oddly enough describes a LOT of what we observe.

    For more on vacuum characteristics, check Wikipedia or other sources under VACUUM, VIRTUAL PARTICLES, HAWKING RADIATION, DARK MATTER, DARK ENERGY, COSMOLOGICAL CONSTANT, CASIMIR EFFECT.

    None of these are EXACTLY "the material of a vacuum" but somehow are naturally inherent in a vacuum...They are characteristics of a vacuum.

    [All of which leads me to conclude there is a lot more to any vacuum than "nothingness".]
  7. Jul 17, 2011 #6
    Thank you for the applicable things to research. I will look at them and post the further questions i have. Thanks everyone! I began to watch Hawkins view of the Universe so hopefully i will begin to understand more about it in the years to come.
  8. Jul 18, 2011 #7
    I have been reading up on vacuum energy and virtual particles too, and have run into some questions. I hope you don't mind if i ask them here, as were both trying to understand the same thing i think it could be helpful to both of us.

    I thought that vacuum energy and zero point energy were two different things. But my teacher (who doesn't have a good understanding of it) says that they are the same thing.

    So if they are the same thing, how is virtual particles created from zero point energy? By definition it cannot be used, Zero point energy is already the lowest possible energy of a quantum system, therefore it is impossible to use the energy: Using it would leave less than the lowest possible energy, which is impossible.

    Also i thought that zero point energy had to do with particles and their energy, while vacuum energy was a ever-present energy with NO particles.

    Is he wrong, if not where am i wrong?
  9. Jul 18, 2011 #8
    I though I would mention this story since it relates to the topic: http://www.nature.com/news/2011/110603/full/news.2011.346.html

    Scientists have apparently found a way to coax virtual particles out of the vacuum and transform them into real ones. Of course, this is not a method that can be used to create more energy than is put into the system.
  10. Jul 18, 2011 #9
    The two are not identical, but they are related.

    The zero-point energy is the ground state of a quantum mechanical system. For example, a hydrogen atom where the electron is comfortably sitting in the lowest orbital is at zero-point energy.

    Vacuum energy is one kind of zero-point energy. It is the ground energy of fields. These fields are interpreted as consisting of virtual particles.

    Personally, it is easier for me to think about what is going on when I stop using the term "particle" and replace it with the word "unit." When I do this, it is easier for me to think about virtual "particles" and quantum mechanics in general.

    From this perspective, you could think about photons like this. There is an electromagnetic field inherent to the vacuum. A disturbance in this field can create a wave. The size of this wave is constrained to carrying distinct units of energy. We call those units photons. Each unit of energy being carried by this wave can only be absorbed at one place, even though the wave itself can spread out, ripple, and interfere with itself.
    Last edited: Jul 18, 2011
  11. Jul 18, 2011 #10


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    That's a fairly bold statement considering that many (if not most) physicists as well as philosophers of science interested in the issue, don't consider virtual particles to be real things. There's been any number of threads on this where it's been discussed ad-nauseam.
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