Zero point energy Exawatt Human What exactly is zero point energy? I know it's "used" in several sci-fi shows, quantum torpedoes, one of Babylon 5's propulsion systems and reactors, and now on Andromeda. I know, or at least I think I know that it has something to do with the energy of the universe or something similar. Is it theoretical, observed, or on the brink of fantasy? tennyson Vedran This may be difficult to describe well so bear with me,according to quantaum mechanics you cannot observe both the position and the velocity of a particle with absolute certainty. Greater accuraccy in observing one property necessiates a corresponding decrease in accuracy for the other. One of the implications of this is that the total energy of the universe is not accurately known."Virtual particles" can form in the vaccumm consisting of a particle and its antiparticle. They form and then immediately annihilate each other constantly in supposedly "empty" space. This is the fundamental nature of the zero point energy. It has been experimentally observed in certain special conditions. For example thier is an extra amount of force between two charged plates that are a certain distance apart called the Casimir force that is attributed to the effect of virtual particles. There are other experiments but this is the most famous. Many have theorized about ways to access the energy of the zero-point but so far it is all conjecture. We aren't even sure how much energy empty space might contain. Delvo2 Nietzschean Ah, yes, ZPE, also known as electromagnetic vaccum energy (the energy left over when everything else has been removed, even electromagnetism): the energy that's there just because the universe can't quite make up its mind that it isn't. (Of course, it also can't quite make up its mind that it IS, which is why we can't feel ZPE, because it's like the XY% possibility of the presence of all forms of energy at every point in the universe, rather than actual energy itself...) In a way, ZPE is a bit like atmospheric pressure. We don't feel it because it pushes equally in all directions. So the energy we DO feel, like when we turn on a light bulb, is actually just a fluctuation, an asymmetry on top of the normal ambient energy, just as the wind we feel is just a little temporarily asymmetrical fluctuation in the air pressure that's always there. Based on the measured intensity of the Casimir effect (in which the two plates experience an attraction toward each other because they're close enough to cancel out exclude certain larger "sizes" [wavelengths] of energy between them but are still pushed by those larger energies from the OUTSIDE), it has been projected that the energy in a given volume of space is some just ludicrous amount, like a few cubic inches' worth of ZPE being enough to boil all the oceans. Again, the air pressure analogy fits; weren't you fairly astounded the first time you found out that every square inch of your body normally has 15 pounds of pressure on it, for a total of tons over your whole body? ZPE has also been postulated as the arbitor of certain relations of matter and space-time. For example, if you're still or if your movement is constant, the energy is equal on all sides, but if you move against the ZPE field, then your atoms and all their associated electric and magnetic fields press into the ZPE field in "front" more than in "back", so there's resistance... and presto, an actual physical explanation for why there's inertia. Other, trickier ideas have also used ZPE flow-imbalances to explain gravity and Einstein's relativity effects on high-speed matter as well. It's even been suggested that ZPE is space-time itself, the universe can be defined as where ZPE happens... which reminds me of the debates over "Ether" and vaccuums and whether or not it was possible for the universe to include places that don't contain anything. If a filter could be devised to respond to ZPE in one direction but not its opposite, then so much energy could be obtained that energy consumption and efficiency would essentially disappear as limitations on our engineering and technology. Also, because quantum mechanics dictates that it can't possibly not happen, there'd always be more just because the universe can't decide there won't be. All other energy sources ever imagined must eventually fall to entropy, but not this one. So the incomprehensibly huge amounts of energy would be available not only immediately, but also permanently. The potential is nearly godlike. Even a filter with a lousy 1% efficiency would have potentialy probably beyond what we can imagine. Unfortunately, the only such filter I'm aware of is the event horizon of a black hole; it can suck in one "virtual particle" of a pair originating just outside it, thus forcing them both to remain "real" while the other one continues on its escape trajectory. Also, if you capture so much energy by forcing particle-antiparticle pairs (PAPPs) not to recombine and annihilate, there's a question of where the half of the particles that you didn't capture will go and what they'll do. As stated above, all particles "push" or "pull" against matter, even electromagnetic ones, although we're not used to thinking of ourselves as getting pushed by our light bulbs. But this force, if a one-way ZPE filter could be made, could also be used for propulsion. One trick would be to make sure you only use the force of a tiny percentage of the ZPE in any one direction, or you'd smash your ship when you turned the engines on, just like crashing it into a moon or planet. The fun thing about this propulsion, for ship design, is that the engines might look like a return to paddles and sails. Another fun implication for fiction authors is that such an engine, when "on" and in use moving the ship around, is actually an energy SOURCE, not an energy SINK. Orpheus Nietzschean While the idea of ZPE as mediator of certain properties of matter and energy has some appeal, it raises some questions in my mind. For one thing, luminiferous ether (the hypothetical omnipresent medium which light waves 'waved') was once cited to explain a similar range of essential properties, but was disproven by (among other things) the famous Michaelsen Morley experiment. Relativity later demonstrated that no such universal background or framework could exist. The ZPE argument for inertia, for example, cannot account for an infinite number of frames of reference, all displaying consistent inertia, in the same space, simultaneously. It would suggest some universal rest frame (which does not exist). The black hole example mentioned in the preceding post would also seem to discredit ZPE - the massive ZPE calculated by the Casimir Effect (and other experiments) would lead to a huge continuous influx of energy into a black hole - sufficient to alter its development, life-cycle, and predicted behavior. The corresponding efflux would also produce a plethora of observable effects. Of course, we have never incontrovertably observed a black hole, so these effects may well be present. It certainly wouldn't be the first time a major revision in accepted black hole theory was required. Hawkin's quantum evaporation was exactly such a revolution - and IIRC after several decades of being accepted, was repudiated by Hawkins himself a few weeks ago. (The details elude me. Perhaps someone can correct or elucidate. I don't mean to disparage or contradict the existence of ZPE, and certainly not the Casimir effect, I simply mean to note some issues with some common formulations of ZPE used in SF, and hope to provoke some discussion. Techfreak Ziana Purple Pixie There's an imo excellent SF book involving Zero Point Energy... 'StarDrive : Zero Point', by Richard Baker. Mobius Nietzschean "was repudiated by Hawkins himself a few weeks ago. (The details elude me. Perhaps someone can correct or elucidate." Et Tu, Hawkins? Actually, Christopher or another poster at the old Andromeda forum let this on last year. But Hawkins might have said it again recently. Bulldawg Magog It may be a little out of date in light of recent advances but here's a pretty good tutorial from Scientific American on ZPE I found about a year back. I'm not sure it goes quite as in depth as some of the explanations provided here but it is a starting point. http://www.sciam.com/1297issue/1297yam.html Orpheus Nietzschean I'll have to retract that bit about Hawking repudiating it. At Anarch's request I just did a hunt for it (IIRC -and apparently I don't- it was a remark made in reply to an objection raised by someone lese, not a Hawkins paper) However, he seems to stand by it in his 60th anniversary symposium in january, so I must be wrong. Dang - I could swear that I could remember not only when I read it, but what else I was doing at the time. Senility ain't pretty. Just imagine what I'll be like when I'm 40. Anarch Artificial Intelligence I finally broke down and trawled sci.physics.research to see if anyone believed Hawking radiation had been overturned. The unanimous consensus of the cognoscenti (Cool phrase or bloated speechifying? You be the judge!) was that, while Hawking radiation has yet to be observed experimentally, it is still very much a part of the extant theories. Ahhhh.... sci.physics.research. An instant inferiority complex from the first post on... Edited to add: Found a couple of useful links on Hawking radiation, although one of them hasn't been updated in a while: The Usenet Physics FAQ And, from the otherwise-wretched sci.physics.relativity (one of those Usenet cesspools to which I was referring earlier), comes this gem of a post: http://groups.google.com/groups?hl=en&selm=92te2b%24m18%241%40woodrow.ucdavis.edu&rnum=18 There's also another theory I've seen mentioned that considers Hawking radiation as an actual tunneling effect through the event horizon, but I haven't been able to find any online references to it. [And, for reference, I still haven't read the article about tardyonic particles tunneling through the luminal barrier to become tachyonic, but I'm beginning to think that this person was probably demonstrating why it couldn't happen, rather than how it could.]