Read about hawking | 12 Discussions | Page 1

  1. S

    A Hartle-Hawking sum over all possible metrics?

    Physicists Stephen W Hawking and James B Hartle 1 proposed that the universe, in its origins, had no boundary conditions both in space and time. To do that, they proposed a sum over all compact euclidean compact metrics. I have heard that they only considered these metrics in order to simplify...
  2. S

    A Can there be a lawless universe (according to Hawking)?

    I got a phrase from a book that Stephen Hawking and his daughter Lucy Hawking published in 2011. The book is "George and the Big Bang" which is a science fiction book prepared for children. I read a phrase on that book that interested me. It was: "Perhaps there are many universes, each with...
  3. A

    A Multiverse reduction in the new Hawking/Hertog model?

    Hawking and Hertog's new paper "A Smooth Exit from Eternal Inflation?" does away with the infinite multiverse of Hawking's previous theory and proposes a cosmology that predicts "a simpler and finite universe". But I can't figure out the extent of this reduction to a "simpler and finite"...
  4. David Prince

    B Gravity and human population, Solved?

    The next questions will be in english and spanish, since my birth language is spanish I may be mistaken in a few english words. --------------------------------------------------------------------------------------------------------------------------------------------- Spanish Debo advertir...
  5. P

    Where will Hawking stand in the future?

    I was discussing this with my class just the other day and now the sad news has come out, I was wondering where everybody thinks Hawking stands and where he will stand in 100 or even 200 years? Will he be as widely known as Newton, Maxwell, and Einstein? Will his research and discoveries be as...
  6. ISamson

    Hawking biography article

    I have found this engaging biography on Stephen Hawking. Interesting information: https://www.space.com/15923-stephen-hawking.html
  7. TAKEDA Hiroki

    I Variation of perfect fluid and Lie derivative

    In Hawking-Ellis Book(1973) "The large scale structure of space-time" p69-p70, they derive the energy-momentum tensor for perfect fluid by lagrangian formulation. They imply if ##D## is a sufficiently small compact region, one can represent a congruence by a diffeomorphism ##\gamma: [a,b]\times...
  8. C

    How exactly does Hawking radiation work?

    Homework Statement For school I'm doing a project on hawking radiaton but I have very big difficulties trying to understand it. I'm trying to understand the matter about: Unruh effect, particle pair (antimatter - matter) and the theory of relativity regarding vaccuum. Homework Equations none...
  9. Q

    A Beckenstein Hawking Entropy

    Does anybody know where I can find a walkthrough of the derivation of Black hole entropy the way hawking did it? (I'm not worried about deriving from string theory or lqg) I'm looking to follow along to understand the assumptions in the derivation.
  10. H Smith 94

    Could light orbit a massive object, like a black hole?

    According to Hawking [1] it is posited that light photons at the event horizon of a black hole must cease to move, and remain motionless for the entire lifetime of the black hole. It is also observed [http://dls.physics.ucdavis.edu/~scranton/LensedCMB/a2218.gif] (and calculated) that the path...
  11. M

    A Solution To The Grandfather Paradox

    Hey There, I would like to share something that crossed my mind the other day, a solution to the grandpa paradox. My solution is quite basic, The Man in the future is going to shoot himself in the past through a portal, He will not do so because if he did, he wouldn't exist in the future to...
  12. Lamdbaenergy

    Hawking Radiation From Black Holes:

    If you only knew the temperature of the black hole, like, if for example, the temperature of a 4 solar mass black hole being around 1.5e-8 kelvin, how could you possibly be able to calculate what wavelengths of radiation the black hole would give off? Would a black hole like this really only...
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