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

Help My Novel's Character

  1. Oct 23, 2013 #1
    Hi Everyone !!

    My latest project includes a physics professor engaged in negative energy research. My question is what type of equipment and its cost would such a laboratory require. You may assume a low eight figure grant (well, it is fiction). You may also include any speculative machinery reasonable technological advances might make available within the next two decades.

    I'll be happy to provide any further information, detail, background you may require to better answer the question as well as the opening chapter for anyone curious as to where I'm going with this.

    Thanx much !!
  2. jcsd
  3. Oct 23, 2013 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    First: What's negative energy in your book? What creates it? How does it function?
    We can't possible say what is needed to research it if we don't know what it is.
  4. Oct 23, 2013 #3
  5. Oct 24, 2013 #4
    My sincerest apologies for being unaware 'negative energy' might have different interpretations especially if one has cats for pets !! :-D

    Following is an excerpt from "The Quantum Mechanics of Black Holes" by Stephen Hawkings published in a 1977 edition of Scientific American which served as my layman's understanding of negative energy:

    "A black hole radiates energy at a rate inversely proportional to the square of its mass. Although the evaporation rate is large only for subatomic size black holes, it provides a crucial link between the laws of black holes and the laws of thermodynamics. The Hawking radiation allows black holes to come into thermal equilibrium with their environment.

    At first glance, evaporation leads to a contradiction. The horizon is a one-way street; energy can only flow inward. So how can a black hole radiate energy outward? Because energy must be conserved, the production of positive energy - which distant observers see as the Hawking radiation - is accompanied by a flow of negative energy into the hole. Here the negative energy is produced by the extreme space-time curvature near the hole, which disturbs the vacuum fluctuations. In this way, negative energy is required for the consistency of the unification of black hole physics with thermodynamics . . ."

    Thank you "Nasu" and "Drakkith" for replying. I greatly appreciate your taking the time.

  6. Oct 24, 2013 #5


    User Avatar
    Staff Emeritus
    Science Advisor

    Yeah... that's not right. There is no "negative energy" flowing into the black hole. Energy is radiated away from the black hole, reducing its mass over time. the mass is turned into energy. This is how energy is conserved.
  7. Oct 24, 2013 #6
    Now I'm really confused.

    This forum contains a thread by "hurk4" titled "Negative energy versus positive energy" He states:

    "Cancellation or generation of positive energy by negative energy and vice versa is so often brought up by very serious physicists (e.g. A. Guth, A.V. Fillipenko) as the argumentation for the possibility of the generation of our universe out of “nothing”, that I hardly dare to question this. As an example or metaphor for it is most often used the so called cancellation of (so called positive) kinetic energy by the (so called negative) gravitational energy . . "

    Although the thrust of his argument is his rejection of negative energy as the cause for something arising out of nothing, he clearly (IMHO) implies negative energy is real. And as he further states, so do the "very serious physicists" A. Guth and A.V. Fillipenko.

    Did Stephen Hawkings publish a refutation to his view that negative energy is necessary to maintain a black hole's equilibrium with the Laws of Thermodynamics ??
  8. Oct 24, 2013 #7
    Further to my point, I invite your attention to a white paper submitted on November 9, 1998 by Adam D. Helfer to Cornell University titled "The Physics of Negative Energy Densities", reference # arXiv:hep-th/9811081. He states:

    "I review some recent results showing that the physics of negative energy densities, as predicted by relativistic quantum field theories, is more complicated than has generally been appreciated. On the one hand, in external potentials where there is a time--dependence, however slight, the Hamiltonians are unbounded below. On the other, there are limitations of quantum measurement in detecting or utilizing these negative energies."

    So. Does negative energy exist or not ??
  9. Oct 24, 2013 #8


    User Avatar
    Staff Emeritus
    Science Advisor

    I think there's a misunderstanding of the terminology by one of us, possibly me. I don't know much about "negative" energy, but I expect it's similar to how potential energy can be positive or negative depending on how you're looking at it.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Threads - Help Novel's Character Date
Need help with gravitational lensing issue! Aug 16, 2017
Help with a novel: uses of a time gradient? Jun 16, 2015
Board: Help with novels/scifi Nov 18, 2011
Sci-fi novel help Jun 8, 2010