What exactly is Negative Energy?

Discussion in 'General Science & Technology' started by Xelios, Dec 20, 2001.

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  1. Xelios We're setting you adrift idiot Registered Senior Member

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    I read about this yesterday and I'm wondering what exactly it's supposed to be. Where might you find some? Is it a special characteristic of any theoretical particle or is it only something you'd be able to attain in a very power particle accelerator?

    The reason I'm asking is that I read about a possible way of FTL travel which involves using negative energy as the power source for a drive unit that would rip space in front of the ship. Then as the space repairs in the back it pushes the ship forward.

    Anyway, any help would be appreciated.
     
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  3. Greg Bernhardt www.physicsforums.com Registered Senior Member

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    one word: gravity
     
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  5. James R Just this guy, you know? Staff Member

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    In the context you are thinking of the important thing is negative energy <i>density</i>. Some kind of negative energy density is needed, in theory, to keep a wormhole open so that a massive object can pass through. In effect, the negative energy density would have a kind of anti-gravity effect which would resist the tendency of the wormhole to collapse in on itself.
     
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  7. esp Registered Senior Member

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    With negative energy does that mean negative mass from
    E=mc^2
     
  8. Xelios We're setting you adrift idiot Registered Senior Member

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    How can negative energy exist in the first place? If we rearrange E=mc^2 for c, you get a root of a negative number which is not possible. Would this mean there is no speed limit for negative energy? Or am I just terribly confused?

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  9. James R Just this guy, you know? Staff Member

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    esp:

    The effects of negative energy density might be something like the effects of a negative mass, if such a thing existed.

    Xelios:

    It seems you are terribly confused.

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    The <i>c</i> in E=mc<sup>2</sup> is a constant. If you solve for it you'll always get the same value: 299792458 m/s.
     
  10. Xelios We're setting you adrift idiot Registered Senior Member

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    Yes, but you should be able to solve for c by rearranging the formula E=mc^2. You would then have to take the root of E/m. However, if negative energy exists, you would have -E/m, which gives you a negative number inside the root. This gives a nonreal answer, not the constant of light.

    As you said, you should always get the same value, not a nonreal answer. So would this imply that negative energy cannot exist in our universe? Or does this equation simply not apply to it?
     
  11. James R Just this guy, you know? Staff Member

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    It suggests to me that in any situation where E=mc<sup>2</sup> applies, a negative energy must also imply negative mass.
     
  12. Xelios We're setting you adrift idiot Registered Senior Member

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    Hmmm, but if mass is just a measure of the amount of matter in an object how can it be negative? I mean, negative mass would mean there is less than 0 "amount" of matter. This would impose a vacuum or something along those lines wouldn't it?
     
  13. Rick Valued Senior Member

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    Vaccum would be Zero mass,it has to be something more than that...black hole? just a stupid thought i know...

    bye!
     
  14. Rick Valued Senior Member

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    If you dont consider any object as stationary then, tachyons (the imaginary particles supposed to be traveling faster than velocity of light without violating rules of relativity,they"ll ne'r stop...)may have a negetive mass...
    these particles are present in the world in which effect preceeds its cause,they theoritically will never stop...
    bye!
     
  15. Xelios We're setting you adrift idiot Registered Senior Member

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    I don't think it could be a black hole, simply because it's mass is very high.

    Haven't read much about tacheyons so I can't really give my opinion on that, maybe James R. could fill us in

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  16. James R Just this guy, you know? Staff Member

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    A negative energy density is not likely to be achieved by having "negative mass", in my opinion. Negative mass would be something different from anything we know about. Negative mass would have anti-gravity. There is no currently known particle which gravitates negatively.

    A black hole has positive mass.

    Tachyons, if they exist, would have <i>imaginary</i> (in the mathematical sense) mass, not negative mass. What this would be like, exactly, is anybody's guess.
     
  17. esp Registered Senior Member

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    y maths has never been all that good, I struggled like hell with calculus, but isn't it

    E = mc^2

    -> E = m
    ----
    c^2

    so

    -E = -m
    ----
    c^2

    ?


    I'm sure to get -ve energy you'd ave to have -ve mass.

    Zion

    Isn't vacuum just the absence of mass while negative mass would be the opposite of mass?
    Perhaps it's more
    anti-mass.

    Keeping to E=mc^2, could we be talking about anti-/negative light as well
     
    Last edited: Dec 31, 2001
  18. James R Just this guy, you know? Staff Member

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    esp,

    You're assuming you need mass.
     
  19. SISGroup Registered Senior Member

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    I agree, there is no particle which has negative mass. So, negative mass should be negative particle, if positive particle mean to particle which has positive mass.

    What is the opposite of particle?

    I think opposite of particle is not energy, even E=mc^2 separate mass and energy into to different side. Or, E/(mc^2)=1 which mean energy and mass are same side. If mass (positive particle) is opposite of Energy, then E/(mc^2) wil = 0 (same value of positive against same value of negative should be result zero)

    then may question: is soul negative particle?

    BTW, Xelios try to find the energy to make space travel, so how we can arrive to other galaxy if it take many years? even we have use speed of light spaceship... oops, I cannot continue....this is not the topic of souls......
     
    Last edited: Jan 3, 2002
  20. Xelios We're setting you adrift idiot Registered Senior Member

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    I think the key to space travel is not to try and accelerate the starship to near light speed, but rather to find loopholes in relativity itself. For example, say one could travel faster than light IF they are travelling through a dimension seperate from the 3 spatial dimensions.

    Accelerating a spacecraft to near light speed is simply too much work, there must be a way to bypass acceleration completely or maybe to make the destination come to us, not the other way around (bending space). That's what I think anyhow.
     
  21. SISGroup Registered Senior Member

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    I think you right, Xelios.
    May we consider to NOT bring our body in space traveling?

    Our anchestors had learned the space, like Maya and Egypt. How they learned the space without telescopes and made calendar system without mathematic?
    Should we learn from them?
     
  22. Rick Valued Senior Member

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    A misunderstood statement.

    Let me clarify.

    for vaccum i said zero mass.the next statement i referred to was with respect to other post regarding negetive mass.i referred negetive mass as black hole.but i was wrong as black hole has positive mass,as James R rectified me...

    bye!
     
  23. esp Registered Senior Member

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    Silly, I know, but would it perhaps be that the heart of the black hole is so dense it could exhibit negative mass properties?
     
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