FOLLOW-UP: What is the 'zero-point energy' (or 'vacuum energy') in quantum physics? Is it really possible that we could harness this energy?















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Adding minus infinity to plus infinity gives mathematicians nightmares and even makes theoretical physicists worry a little. Fortunately, nature does not worry about what the mathematicians or physicists think and does the job for us automatically. Consider the grand total vacuum energy (once we have added in all quantum fields, all particle interactions, kept everything finite by hook or by crook, and taken all the proper limits at the end of the day). This grand total vacuum energy has another name: it is called the "cosmological constant," and it is something that we can measure observationally.

In its original incarnation, the cosmological constant was something that Einstein put into General Relativity (his theory of gravity) by hand. Particle physicists have since taken over this idea and appropriated it for their own by giving it this more physical description in terms of the ZPE and the vacuum energy. Astrophysicists are now busy putting observational limits on the cosmological constant. From the cosmological point of view these limits are still pretty broad: the cosmological constant could potentially provide up to 60 percent to 80 percent of the total mass of the universe.

From a particle physics point of view, however, these limits are extremely stringent: the cosmological constant is more than 10(-123) times smaller than one would naively estimate from particle physics equations. The cosmological constant could quite plausibly be exactly zero. (Physicists are still arguing on this point.) Even if the cosmological constant is not zero it is certainly small on a particle-physics scale, small on a human-engineering scale, and too tiny to be any plausible source of energy for human needs--not that we have any good ideas on how to accomplish large-scale manipulations of the cosmological constant anyway.

Putting the more exotic fantasies of the free lunch crowd aside, is there anything more plausible that we could use the ZPE for? It turns out that small-scale manipulations of the ZPE are indeed possible. By introducing a conductor or a dielectric, one can affect the electromagnetic field and thus induce changes in the quantum mechanical vacuum, leading to changes in the ZPE. This is what underlies a peculiar physical phenomenon called the Casimir effect. In a classical world, perfectly neutral conductors do not attract one another. In a quantum world, however, the neutral conductors disturb the quantum electromagnetic vacuum and produce finite measurable changes in the energy as the conductors move around. Sometimes we can even calculate the change in energy and compare it with experiment. These effects are all undoubtedly real and uncontroversial but tiny.

More controversial is the suggestion, made by the physicist Julian Schwinger, that the ZPE in dielectrics has something to do with sonoluminescence. The jury is still out on this one and there is a lot of polite discussion going on (both among experimentalists, who are unsure of which of the competing mechanisms is the correct one, and among theorists, who still disagree on the precise size and nature of the Casimir effect in dielectrics.) Even more speculative is the suggestion that relates the Casimir effect to "starquakes" on neutron stars and to gamma ray bursts.

In summary, there is no doubt that the ZPE, vacuum energy and Casimir effect are physically real. Our ability to manipulate these quantities is limited but in some cases technologically interesting. But the free-lunch crowd has greatly exaggerated the importance of the ZPE. Notions of mining the ZPE should therefore be treated with extreme skepticism

Updated on August 18, 1997

From the way some enthusiasts talk about the zero-point energy, one might think that unlimited power is lying all around just waiting to be harnessed. Like many ideas that seem too good to be true, this one falls apart on closer examination, although the concept of the zero-point energy is quite fascinating in and of itself. John Obienin, a materials science researcher at the University of Nebraska at Omaha, explains:



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  1. 1. BillT 09:09 PM 2/2/09

    Can you update this article and provide some information on these two gentlemen? They have been doing research in this field for some time and were awarded a patent in May.

    http://www.calphysics.org/Patent7379286.pdf

    https://www.cu.edu/techtransfer/about/newsreleases/2007/Fall2006_poc_winner_announcement.html

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  2. 2. Liljencroowna 04:01 PM 5/25/09

    Yes, I agree with BillT.

    Can you please update this article or maybe write a new one?

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  3. 3. allen007 07:16 PM 10/17/09

    Here is just a thought. There is inherently "energy" in space, as there is energy in the exhaust of a jet as it travels through the atmosphere. Is it collectible and usable? Not on a safe scale. The problem would be that you may create an energy void at the point of collection, or the path as it may be. Thus changing the dynamics of the local ZPM. Reducing the local ZPM to a true Zero state or it theory worse, creating a true void that may affect space/time itself. Yes this is a stretch, however it is not within out grasp yet to even theorize what may happen to the "space" that we draw any usable energy from, if there is any there to "collect".
    If you think of the ZPM as surface tension, as in water, what happens when you disturb the tension? A ripple in a puddle is one thing, a ripple is the spacial dynamics of the solar system, or the galaxy. Where is the science to support the naysayers on this. There is not any. We as a species have not come far enough to meddle in space/time with out KNOWING the consequences BEFORE we "poke the bear with a stick".
    If you throw out size and look at things on a equal scale. How much "empty" space, relativity, is there in an atom, compared to a solar system, galaxy, or universe.
    It all comes down to humanities definition of scale. There in no truly empty space yet there is also not much of anything in that space either. Like Quarks or string theory, scale is the only thing that is a variable. The rest is a given , that we are trying to find the right math to calculate.

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  4. 4. Gagh 01:22 PM 3/12/10

    "The next step is to realize that the electromagnetic field can be thought of as an infinite collection of coupled oscillators--one at each point in space."

    Well, I think this statement is a little bit false. As I understand the quantization of the electromagnetic field, in a certain sense you can see it as an infinite number of harmonic oscillators (each one with a different frequency), but neither are they coupled, nor do they exist in "real" space. Rather, it is just a a formal analogy to such a system of harmonic oscillators, which helps you doing the actual quantization step.

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  5. 5. zeropoint 11:34 PM 3/16/10

    I was initially skeptical that you could every harness <a href="http://www.discoverzeropoint.com">zero point energy</a> products until I went to a demonstration of a new product that did exactly that. Go to http://www.discoverzeropoint.com to find out more.

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  6. 6. debu 10:52 AM 4/15/10

    Vacuum energy is ether and produced at common spherical boundary of our matter and outside antimatter universe on opposite entropy path and injected into our universe to cause expansion and gravity. So vacuum energy total is ever increasing and not zero. Please read the theories of durgadas datta published in ASTRONOMY.NET in year 2002. --durgadas.ddatta@gmail.com

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  7. 7. Eureka999 02:24 PM 6/27/10

    To understand zero point energy it is important to have a handle on qutum gravity at the smallest scale. this also suggest it will be very difficult to ectract energy from inherent space-time energy. See: The formulation of harmonic quintessence and a fundamental energy equivalence equation. Physics Essays 23:311-319

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FOLLOW-UP: What is the 'zero-point energy' (or 'vacuum energy') in quantum physics? Is it really possible that we could harness this energy?

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