Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!

 



Forgot your password?
typodupeerror
×

The Energy of Empty Space != Zero 362

Raindeer writes "Lawrence Krauss (well-known physicist and author of The Science of Star Trek) invited a group of 21 cosmologists, experimentalists, theorists, and particle physicists and cosmologists. Stephen Hawking came; three Nobel laureates, Gerard 'tHooft, David Gross, Frank Wilczek etc. He wrote about the conclusions of this session in Edge; in short: 'there appears to be energy of empty space that isn't zero! This flies in the face of all conventional wisdom in theoretical particle physics. It is the most profound shift in thinking, perhaps the most profound puzzle, in the latter half of the 20th century. And it may be the first half of the 21st century, or maybe go all the way to the 22nd century. Because, unfortunately, I happen to think we won't be able to rely on experiment to resolve this problem.'"
This discussion has been archived. No new comments can be posted.

The Energy of Empty Space != Zero

Comments Filter:
  • New news? (Score:5, Interesting)

    by haluness ( 219661 ) on Monday July 10, 2006 @10:47AM (#15691110)
    I thought that this was previously known - isn't the Higgs field (http://hepwww.ph.qmul.ac.uk/epp/higgs1.html [qmul.ac.uk]) supposed to endow empty space with a non-zero energy? (Or maybe it was postulated but not observed)
  • Science Fluxion (Score:5, Interesting)

    by Doc Ruby ( 173196 ) on Monday July 10, 2006 @10:57AM (#15691188) Homepage Journal
    And I thought "Zero Point Energy" was just technobabble [wikipedia.org].

    Fact: what you know that you have proven to yourself
    Belief: what you know that you could prove to yourself but have not
    Faith: what you know that you can not prove to yourself

    Is there a distinction between faith you can't prove to yourself because it's not proveable (metaphysics), and faith you're too dumb to prove?
  • The Casimir effect (Score:5, Interesting)

    by MC68000 ( 825546 ) <brodskie@NoSpAm.gmail.com> on Monday July 10, 2006 @11:03AM (#15691233)
    The perfect demonstration of zero point energy is the Casimir effect, which has actually been observed in a laboratory.

    http://en.wikipedia.org/wiki/Casimir_effect [wikipedia.org]
  • by PIPBoy3000 ( 619296 ) on Monday July 10, 2006 @11:09AM (#15691281)
    The interesting part is not that it exists, but that if you apply the theory empty space has 120 orders of magnitude more energy than the visible universe. Still, you can take the same theory and apply it to a hydrogen atom and get a number that is validated by experiment to nine decimal points. So the big question is, how do you use the same theory (relativity and quantum mechanics) to make a great prediciton about hydrogen atoms and a terrible prediction about vaccuum energy?

    Still, the point of the article isn't about vaccuum energy, but rather the anthropic principle. The concept is that there's a constant in our universe that almost precisely cancels out this vaccuum energy. This is purely by chance and we see it because if it didn't happen, we wouldn't be around to talk about it.
  • Re:New news? (Score:5, Interesting)

    by frankie ( 91710 ) on Monday July 10, 2006 @11:22AM (#15691385) Journal
    Yes, Krauss is talking about vacuum fluctuations and such, well-known concepts. The article is mainly him describing how freaked out he is that there are these two enourmous counter-balancing forces that almost but not quite perfectly cancel each other out, so that out at 120 decimal places there's a positive value left over.

    He then proceeds on to the standard "argument from conditional probability" where the universe has exactly these constants because if it didn't we wouldn't be here to see it. Which is a comfortable thing to believe but isn't predictive science.

    I'm guessing this essay is a seed for his next book.
  • by kalirion ( 728907 ) on Monday July 10, 2006 @11:32AM (#15691455)
    What about background radiation? That's everywhere, isn't it? Or are we considering "empty space" as a theoretical place where there isn't even any radiation at all? And if the Casimir effect counts, wouldn't gravity count as well? Well, I guess there could conceivably be points in space where gravity is 100% cancelled out....
  • Polarity (Score:3, Interesting)

    by roman_mir ( 125474 ) on Monday July 10, 2006 @11:51AM (#15691593) Homepage Journal
    It's funny that I happened to think about this subject last week for no apparent reason (thoughts like this just pop into my mind, damn that astronomy minor,) and I thought wouldn't it make sense if gravity had polarity?

    A gravitational well possesses some energy, which at minimum depends on its mass, the gravitational pull towards the center of that mass can be seen as one pole of a gravitational 'magnet', if that were the case, where would be the opposite pole of that mass? It could be that the entire space/time in the universe has to stretch to accomodate the difference in gravitational potential. So it stretches enough to counterbalance the energy of the gravitational well. There must be some sort of communication between the opposite poles, either by 'gravitational waves' or some gravitational particles (gravitons?) or maybe both. If it were waves, it would have looked as if ripples on the surface of a pond were moving out in 2 dimensional space from the center of the gravity well, and the further these ripples move away from the center of the well, the more they subside.

    But these ripples have to be absorbed by something, this something is the normal space, and the more mass there is in the universe, the more of this 'normal empty' space there must be to balance out that mass.

    Based upon all of these assumptions, which I admit are nothing more than speculations at this point, I could even introduce some ideas on the creation of the universe:

    Imagine a totally empty space. Suddenly there was an influx of mass at one point in this space. This influx created a gravitational imbalance in the space and forced the space to balance out this potential by 'creating' more empty space. If any of the above makes sense, I would say that appearence of 'empty space' is actual property of non-empty space, but it takes much more of this 'empty space' to balance any small amount of non-empty space. So while the amount of non-empty space was not very large, the amount of 'empty space' had to be astronomically greater.

    So the more of the non-empty space appears in the universe, the more empty space is provided as a balancer.

    -
    This is all my own conjectures and should not be taken too seriously. yet :)
  • ... when Einstein first derived it. Remember, "E=mc^2" is just the first term in the Taylor expansion for relativistic mass of a moving body:

    E = m c^2 sqrt( 1 / (1 - v^2/c^2) )

    which expands to the approximation

    E ~ m c^2 + m v^2/2 + ...

    and recovers the classical kinetic energy equation (that second term) from the Lorenz contraction formulae.

    Einstein is reputed to have worked for a while to try to explain away the mc^2 constant term on the front (which doesn't affect classical motion since it is constant), but it was not measurable until nuclear decay was characterized. Chemical reactions don't release enough energy for the binding-energy mass loss to be measurable, but nuclear reactions due. Every (non-failing) chemistry student is familiar with the mass deficit in bound nuclei (the atomic mass of hydrogen is more than 1/12 the atomic mass of C-12, because the C-12 nucleus is tightly bound and lost some mass/energy when it stuck together).

    My point is that the mere fact that something is not measurable today does not make it completely senseless. The fact that nuclear mass deficits and corresponding energy loss during radioactive decay agreed with Einstein's relation was a major early win for Einsteinian relativity.
  • by 0xABADC0DA ( 867955 ) on Monday July 10, 2006 @12:17PM (#15691777)
    A bug trap uses no energy and does not violate any thermodynamic law, yet it works. It just creates a condition where the bug is more likely to get in than out. Zero-point energy could be the same kind of deal, where you make a construct that allows you to 'collect' the energy in some way. This also would not violate any theory of balance if you consider the whole system including where this energy comes from. And if this is from outside what we consider our universe, for example some meta-verse or a bug in the simulation of ours, then to us this would seem indistinguishable from free energy.

    I'm not saying that a 'zpm' could be built and generate free power, but to remind that laws of balance only hold over closed systems. For example if the room you postulate is connected to the atmosphere you can harness the 'uniform pressure' as it changes over time as low/high pressure systems pass by. Thus, you are getting 'free energy' from outside the system, drawing from the global heat. From the perspective of the room this is energy out of nowhere or free energy.
  • by trelayne ( 930715 ) on Monday July 10, 2006 @12:27PM (#15691850)
    This is already known in theoretical quantum physics. In fact NASA has funded research into it with the long range goals of achieving propellant-less propulsion.

    The Casimir Effect is also an experiment that is touted as ultra-precise proof of the phenomenon.

    And there are a number of tantalizing theories that are built on its existence and have been published in the usual top ranking physics journals. Some suggesting that vacuum energy is responsible for the very structure (and hence stability) of the physical universe.

    For example: http://www.calphysics.org/ [calphysics.org] explores the possibility that vacuum energy fluctuations account for mass (even particle mass!), inertial forces and [through an elegant corrolary] gravity. This opens up possibilities that go well beyond star trek.

  • by brian0918 ( 638904 ) <brian0918.gmail@com> on Monday July 10, 2006 @12:47PM (#15691998)
    Krauss is always pulling stunts like this. I was a physics undergrad in his dept., and recall hearing about a huge prank that was pulled on a class he taught:

    In Rockefeller 301, the main lecture room, there are maybe a hundred old uncomfortable desks bolted to the floor. One night, some students from his class came in, unbolted all the desks, turned them around, then bolted them back down. One of them wrote on the chalkboard in big letters, "Krauss's big head turns students away!" They had to cancel several classes early the next day, as maintenance rushed in to turn all the desks back around. The funny thing is that the comment remained on the chalkboard for a week or so after the incident--apparently everyone was in agreement about it.

    Another interesting incident... at the Stephen Hawking lecture a few years ago, when the school randomly decided to give him the Michelson Morley award (basically because they would never get another person so esteemed to talk at the school), the interim president (Hundert) of the school was giving a lecture, holding the award, and getting ready to present it. As he was about to bring the award over to Hawking, Krauss does some sort of stunt in grabbing the award away from Hundert without looking weird, and takes it over to Hawking. He then gets his photo opportunity with Hawking.

    I also recall earlier that day, during Krauss's lecture, and later quoted in the school paper, him mentioning that he was one of the key figures behind dark matter research, which is total nonsense.

    One final example that I remember way back as a freshman: I was sitting outside the professors' offices waiting for someone, and heard some yelling, then saw Krauss's secretary run out in a total fit, tears streaming from her eyes, face bright red. She's still around today though, so they must be paying her a lot. I don't think anyone could handle him on a daily basis for less than $60k a year.
  • by dino213b ( 949816 ) on Monday July 10, 2006 @01:57PM (#15692511)

    This sounds like a classic setup. A star trek "scientist" wants to find a favorable answer to reconcile the real world with his fantasy, so he:

    • arranges a think tank to meet at a conference
    • sets a time constraint on the think tank (conference time limitation)
    • asks THE question he wants answered
    • waits until the end of this time-constrained conference for the answer

    And the end result - a nice juicy "yeah..sure.. align the phase.. inverters" answer that he sought in the first place. Call me a skeptic, but that sounds like the classic T.S.F. http://en.wikipedia.org/wiki/Texas_sharpshooter_fa llacy [wikipedia.org] . By tampering with the normal course of the scientific method, a non-scientific answer was produced. Anyone else see a problem here?

    I love imagination as much as the next guy..but c'mon...

  • Tesla's Aether? (Score:2, Interesting)

    by saintory ( 944644 ) on Monday July 10, 2006 @02:47PM (#15692846)

    It took all those brains to just now discover something that has been known for over 100 years?

    According to Tesla's Dynamic Theory of Gravity [wikipedia.org] space was never empty and could be explained by an Aether. Apparently he thought you could get energy out of space. Considering this is a hot topic on Wikipedia [wikipedia.org] it would seem to me that a paradigm shift [wikipedia.org] is what we need next.

  • by Anonymous Coward on Monday July 10, 2006 @02:58PM (#15692920)
    You must have done very poorly in our program at Case: (a) you seem very bitter, and (b) you cannot seem to get any fact correct. :)

  • by maillemaker ( 924053 ) on Monday July 10, 2006 @04:47PM (#15693694)
    I found the author to ramble and repeat himself a bit. I kept scrolling back going, "Wait, didn't I just read this?" thinking I had hit the wheel button or something.

    The thing I found most interesting out of the whole TFA, though, was this last bit:

    "That is, we live in one universe, so we're a sample of one. With a sample of one, you have what is called a large sample variance. And maybe this just means we're lucky, that we just happen to live in a universe where the number's smaller than you'd predict. But when you look at CMB map, you also see that the structure that is observed, is in fact, in a weird way, correlated with the plane of the earth around the sun. Is this Copernicus coming back to haunt us? That's crazy. We're looking out at the whole universe. There's no way there should be a correlation of structure with our motion of the earth around the sun -- the plane of the earth around the sun -- the ecliptic. That would say we are truly the center of the universe."

    Wow. What if we really /are/ the center of the universe? Sure makes me think twice about the whole God thing...

    Steve
  • by brian0918 ( 638904 ) <brian0918.gmail@com> on Tuesday July 11, 2006 @12:29AM (#15695904)
    "1. The prank you mentioned was an April Fool's joke carried out on another very popular professor, and had nothing to do with Prof. Krauss at all... there was nothing written on any blackboard... just had the chairs turned around in advance of a big undergrad class before a test."

    I heard it second-hand. I can't help if you say I heard it wrong, although yours is hearsay just as much as mine. At least I am logged in. You could be anybody.

    "Prof. Krauss chaired the Michelson-Morley Prize committee that gave the prize to Hawking, and Prof. Krauss brought him to Case for a meeting he had organized, and the award event was coordinated to coincide with that meeting. The President was invited to present the award to Hawking, which he did, along with a Trustee of the University."

    Nope, you are wrong. I was at the event, very close to the stage. While the President did indeed hold the award as he talked about presenting it, it was ultimately Krauss who took the award and presented it. I don't care how involved he was in planning the day. It was clear that the President was going to give the award to Hawking, and Krauss decided he should be the one to do it, and kindly swiped the award from the President.

    "etc etc.."

    I can't rebut these comments :P
  • by andersa ( 687550 ) on Tuesday July 11, 2006 @06:05AM (#15696632)

    I don't think anyone expected that a weekend conference would bring about the final answer to the quantum gravity problem. But getting great minds together to discuss wacky ideas is a good thing as far as I am concerned. Physics conferences are common occurances. I just wish they all took place on exotic tropical islands..

    My main problem, being a physicist myself, was that the essay mostly read like mindless gibberish, repeating the same sentences over and over again, as if the repetition would somehow bring more clarity.

I've noticed several design suggestions in your code.

Working...