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Negative Energy is the exact opposite of ordinary energy as it would move in the opposite direction from its momentum and accelerate in the opposite direction of an applied force. It would also warp space time in the opposite way from ordinary matter meaning that it would warp space time in such a way that it will produce repulsive Gravity. If there was an equal amount of positive and negative energy then there would be zero total energy. Negative energy if it exist could potentially be used to stabilize wormholes as well as for warp drive.

How likely is it that negative energy actually exist in our universe?

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  • $\begingroup$ There is a theorem which says repulsive gravity cannot happen under "normal" circumstances. $\endgroup$
    – Ryan Unger
    Commented Feb 1, 2016 at 5:36
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    $\begingroup$ I'm not sure I want to touch stable wormholes or warp drives, but negative energy is an interesting question. Would negative energy have negative mass? E=MC^2 would imply that it would. My guess is that it doesn't exist, but I'm just a hobbyist. $\endgroup$
    – userLTK
    Commented Feb 1, 2016 at 5:58
  • $\begingroup$ Related: physics.stackexchange.com/q/87425 and physics.stackexchange.com/q/69521 $\endgroup$
    – userLTK
    Commented Feb 1, 2016 at 6:42
  • $\begingroup$ Possible duplicate of: Does matter with negative mass exist? $\endgroup$ Commented Feb 1, 2016 at 6:52
  • $\begingroup$ Let us know when you find some... that's really all there is to it in science: empirical evidence. Having said that, even if there was repulsive gravity, energy would still be defined the same way it is today and its sign would simply depend on whether a system is doing work or work is done on a system. $\endgroup$
    – CuriousOne
    Commented Feb 1, 2016 at 9:01

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Here is a flow chart of the forms of energy, with links .

energy

Conservation of energy is one of the fundamental laws governing physical systems and is the only reason why one can talk of "negative energy"

here is a breakdown of the forms that **Conservation of energy ** takes enter image description here

In almost all frames negative energy exists, in the sense of conservation of energy, for example between potential forms and kinetic forms. Look at the energy levels of the hydrogen atom, for example, as a consequence of conservation of energy. It is only in the special and general relativity where the concept of "negative energy" becomes problematic, when it ties up with the mass energy equivalence. Otherwise, negative energy means that, from conservation of energy, positive energy also exists in the system, because of the energy conservation law.

Thus the question has "unexpected" meaning only if it is asking whether negative masses exist, not in the formulation of your question, where the answer is "yes".

It is only negative masses that would behave the way you describe:

as it would move in the opposite direction from its momentum and accelerate in the opposite direction of an applied force. It would also warp space time in the opposite way from ordinary matter meaning that it would warp space time in such a way that it will produce repulsive Gravity.

All these are results from the existence of negative mass, not negative energy, which exists in all classical systems.

The problem of whether antiparticles have also negative gravitational mass is under experimental exploration.

We observed the times and positions at which 434 trapped antihydrogen atoms escaped our magnetic trap, and searched for the influence of a gravitational force. Based on our data, we can exclude the possibility that the gravitational mass of antihydrogen is more than 110 times its inertial mass, or that it falls upwards with a gravitational mass more than 65 times its inertial mass.

The experiments have a long way to go.

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Believe it or not, negative energy actually does exist, in fact, it is all around you. The problem is, it "disappears" almost as soon as it forms. Due to the phenomena of quantum tunnelling, there exists the constant "creation" of virtual particles, and virtual antiparticles. However, these virtual particles and antiparticles "destroy" one another within fractions of a second upon forming. This is actually due to the fact the universe resides in a "False Vacuum State", where the total universal energy constant is not at the lowest potential rest energy. Because e=mc² states that matter can neither be created, nor destroyed, only converted into one form or another, in order for virtual particles to exist, there must form a corresponding virtual antiparticle to carry a negative energy value to ensure a net system energy of zero, otherwise the laws of energy conservation are violated. This is actually how black holes evaporate via Hawking Radiation. As virtual particles forming at the event horizon are ejected from orbit of the black hole, antiparticles are sent downward into the singularity, taking away energy from the black hole as the virtual particles become real particles. If one were to somehow trap the virtual particle, -such as if the antiparticle escaped the black hole instead- the antiparticle would become real. However, this would hold no practical value, as the now "real" antiparticle would still be neutralized by interaction with ordinary positive energy matter.

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100 %. Negative energy is a proven fact, both theoretically and by measurements.There are a lot of papers and lectures about it. For example: Ford.Roman classic paper

another "I. INTRODUCTION It is well known that quantum field theory allows for the existence of negative energy density, which constitute local violations of the weak energy condition. For a recent review, see Ref. 1. ..."

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  • $\begingroup$ I've removed my downvote now that you've provided references, but would like to point out that (1) both papers are by the same authors, and (2) both are theoretical papers, not experimental. Hence they're far from establishing negative energy as a "proven fact". That negative energy is allowed by QFT doesn't mean that it exists. $\endgroup$
    – Eric Smith
    Commented Sep 22 at 0:34

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