Researching Negative Energy: Where to Start?

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Discussion Overview

The discussion centers around the concept of negative energy, particularly in relation to its properties and implications in physics. Participants explore various interpretations of negative energy, its relation to gravitational and electric potential energies, and its theoretical underpinnings in general relativity and classical mechanics.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses difficulty in finding credible sources on negative energy, specifically seeking information that does not conflate it with non-scientific concepts.
  • Another participant asserts that all forms of energy bend spacetime, but suggests that one could consider scenarios where general relativistic effects are negligible, providing examples such as gravitational binding energy and electric potential energy.
  • A third participant references the positive energy theorem in general relativity, indicating a distinction from Newtonian gravitation where total energy lacks a lower bound.
  • A participant emphasizes the need for clarification on what is meant by "negative energy," suggesting that the term may have different meanings in physics compared to the original inquiry.
  • One participant mentions encountering the concept of negative energy in the context of NASA's Quantum Thruster project, noting their limited understanding of the energy's properties.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the definition and implications of negative energy. There are multiple competing views regarding its interpretation and relevance in different physical contexts.

Contextual Notes

There is a lack of clarity regarding the specific definition of "negative energy" as understood by participants, which may lead to misunderstandings in the discussion. The conversation also highlights the dependence on context, such as classical mechanics versus general relativity, when discussing energy types.

Kolten
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Hello, I apologize if this is not posted in the right section.
I've been trying to learn about negative energy, the kind that can't bend space-time, though when I try to search it, it mostly shows random sites on mythical negative spirtits being negative. So does anyone know a place I can research negative energy properly?
Thank you in advance.
 
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All forms of energy bend spacetime.

But if you want you can pretend gravity doesn't exist, or consider a situation where general relativistic effects are negligible. In that case, there are lots of examples of negative energy. For example gravitational binding energy is negative in Newton's theory, as is the electric potential energy between two opposite charges. In general you can add or subtract any overall constant you want from all potential energies without changing anything (so you could make all energies negative if you really wanted to).
 
I don't know why this is in QM, it should be in GR but anyways: there is a very famous result in GR that was proven most elegantly by Ed Witten which addresses your question. It is called the positive energy (mass) theorem: http://en.wikipedia.org/wiki/Positive_energy_theorem

This is unlike Newtonian gravitation theory wherein the total energy of a system has no lower bound in the reals.
 
Kolten said:
Hello, I apologize if this is not posted in the right section.
I've been trying to learn about negative energy, the kind that can't bend space-time, though when I try to search it, it mostly shows random sites on mythical negative spirtits being negative. So does anyone know a place I can research negative energy properly?
Thank you in advance.

The problem whenever we get a question like this is that (i) there is a proper and clear idea of "negative energy" as used in physics; and (ii) it is unclear what you mean by "negative energy".

First of all, where did you get the idea of "negative energy"? Did you hear it from somewhere or read about it somewhere? A valid reference would be nice.

Secondly, based on what you read, what exactly do you think you understand as being "negative energy"?

It is essential that we clear this up because what you mean by negative energy might not be what physicists consider to be negative energy. Without that clarification, we could be talking about two different things and all our responses and discussion will simply miss each other.

Take note that just in classical mechanics alone, "negative energy" is rather common. An attractive field such as gravity is often designated as a negative potential energy. This is because we can always move the reference "zero" level to where ever we wish, since in practically all instances, it is the CHANGE in the energy that matters, rather than the absolute value.

So it is unclear if you are aware of this, or if you have something in particular in mind. Thus, we need a lot more explanation from you.

Zz.
 
Alright, well I heard about it when reading up on one of NASA's projects the Quantum Thruster. Negative energy used by the quantum thruster bend both space in front of it and behind of it. But since my understanding of the energy is so limited, I can't describe is anymore.
 

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