Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is anti-energy?

  1. Dec 20, 2003 #1
    What is anti-energy? Does it have some of the awesome energy-based counterarts of antimatter? Applications?
  2. jcsd
  3. Dec 21, 2003 #2


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    I am pretty sure the term anti-energy is not used in genuine physics. Here are two topics that may have suggested the term to you.

    Anti-matter is made up of anti-particles. Each kind of quantum particle has an anti-particle, and if some kind of particle meets its anti-particle, they annihilate, producing photons. Anti-matter has the same kind of (positive) energy that ordinary matter does, and in that annihilation, the postive energy of both particles adds.

    Negative energy is a concept that principally concerns general relativity. There are a number of (far out) solutions of the GR field equations that have the energy going negative. Nobody truly knows what that means, although you'll see lots of folks willing to tell you.

    Negative energy and anti-matter don't have much to do with each other. You can't use one to get the other.
  4. Dec 30, 2003 #3
    It also concerns parapsycologists, ghosts and all of this stuff...

    Jocking appart, what is the negative energy in general relativity? is a specific concept of GR or is simply that the solutions are negative numbers?

    Negative values for energy are common on classical and semiclassical physics. This only deppends on the reference value you set for the energy.
  5. Dec 30, 2003 #4


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    The negative energy in the GR solutions for worm holes and metric engineering would be genuine if the solutions were physical. Physicists are reluctant to call the solutions unphysical, because that would be arbitrary. What if it were discovered that black holes solutions had negative energy somewhere?

    So they allow the solutions would be physical but not until someone comes up with the negative energy. Which they hope never happens, because that way lies FTL, and FTL leads to time travel and time travel breaks causality.
  6. Jan 5, 2004 #5
    Thank you for your explanation selfAdjoint.

    What does FTL means?
  7. Jan 5, 2004 #6
    Faster than light....
  8. Jan 5, 2004 #7
    Though I don't think anyone seriously believes matter can travel FTL its a known fact that information travels faster than, and I'm not talking gossip.

    Its been found that you can arrange 2 electrons so they have opposite spins. There total spin in this case = 0. Now if you measure the spin of one of the electrons in a particular way then the electron will always measure, say, -1. When the other electron spin is measured, and it doesn't matter how, it will indicate 1. And it works opposite also. You can use the other method to measure the first electron and it will then measure 1. And no matter how you then measure the second electron it will measure -1. And the moment a person measures the first electron "instantly" the second measures the opposite

    Now it turns out you can then separate the two electrons any distance - it could be across the galaxy - and this effect will still occur. Instantly. A pretty neat trick to try and get your head around but its all been proven.

    My own theory of how this happens is this:
    Empty space is not empty at all. Every bit of it is filled with quantum energy just as the earliest quantum scientists postulated but could never quite believe. The reason we don't experience it is because we don't live at the quantum level. Everything we do and see equates to what we would call "drift" in a conductor. (This is just an analogy) In a conductor even though the signal sent though the front of the wire appears to come out the other end at near the speed of light it doesn't mean the electron is going very fast. Just the information is going that fast like the effect of falling dominoes. Individual dominoes, or electrons, are probably only moving centimeters per second. This is the "drift" speed.

    I think in our universe all matter is restricted to to a top drift speed which happens to be the speed of light. But at the quantum level, if you are able to actually isolate just 1 quantum of energy, then if you push on it, that quantum will propogate across the universe instantly rather than be restricted to the speed of light. In other words there is a chain of dominoe like quantums of energy between the two electrons under discussion that each get moved when the first electron's spin is measured. And that information travels instantly, not at the speed of light.
    Last edited: Jan 5, 2004
  9. Jan 5, 2004 #8


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    I won't comment on your own theory, but this piece of misunderstanding deserves a correction.

    The phenomenon you are describing is called entanglement. It results in a higher coincidence of states between separated particles than could be accounted for by classical physics. The reason it can't be used to transfer information is that your description of how to do that (or any description of how to do that) is classical, and the phenomenon is completely quantum. Uncertainty means you don't have the control over the particles you think you will. You can never be sure the particle you choose to tweak isn't already tweaked. And you only get one tweak; the first one destroys the entanglement. So the entanglement can only be seen in the statistics of particles.
  10. Jan 5, 2004 #9
    Consider my decription of entanglement in the classical sense. Its much easier to describe things that way, and it could be argued, impossible in the quantum sense. So I don't try hard. In my head I'm thinking exactly the way you are.
  11. Oct 18, 2004 #10
    Actually, from a theoretical standpoint, time travel could possible exist within the bounds of causality. Some scientists have theorized that if you were to travel through time (at least backwards) you could end up in an alternate existense or universe. One similar to our own but with a slight divergence in events, possibly even the fact that you existed in a time that you could not possibly exist in. By just being in that universe it is different from our own.

    There is also the possibilty that you have created an alternate universe by traveling back. No one really knows what effect you would have, at lost not until someone actually travels through time. Who knows, we could destroy the universe by creating an infinite paradox. Go back and kill your grandfather and you won't have been born, but that also means that you won't have killed your grandfather. So who really understands what would happen.

    But on a lighter note if you could change the past it would be nice to go back to 1986 and invest in microsoft :tongue2: .
  12. Oct 26, 2004 #11
    Thanks for clearing that up. I've often wondered in the back of my head why the principle of entanglement couldn't be used in principle to transfer information instantaneously... Would be handy for those robots many light-minutes away, and have ramifications for possibly sending very small sensor objects to other stars. Now I know. :)
  13. Oct 27, 2004 #12


    User Avatar
    Science Advisor
    Gold Member
    2015 Award

    Mental entanglement is more like it. There is nothing to clear up. No information is transfered faster than light by quantum entanglement.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?