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

Do black holes violate conservation laws?

  1. Jan 10, 2014 #1

    Radarithm

    User Avatar
    Gold Member

    I was arguing today with a friend and the argument seemed pretty pointless because we had nothing to back up our facts with, so I thought about hearing your opinion(s). Do black holes violate laws such as the conservation of matter + conservation of energy? I'm currently leaning towards 'yes'. What do you guys think?
     
  2. jcsd
  3. Jan 10, 2014 #2

    Drakkith

    User Avatar

    Staff: Mentor

    Not at all. First, there is no such thing as the "conservation of matter". Matter can be destroyed and created, and in fact this happens all day every day at various particle colliders around the world.

    The real conservation laws, such as conservation of energy and conservation of mass, are not violated by a black hole. Matter and light that passes past the event horizon simply adds to the black hole's mass. The total energy and mass of the system (the black hole and the surrounding universe) is unaffected.
     
  4. Jan 10, 2014 #3
    You should read The Black Hole War written by Leonard Susskind.
     
  5. Jan 10, 2014 #4
    This might be a misleading statement Drakkith. I wouldn't say destroyed, but rather transformed.

    As for being created, I have absolutely no idea how you could create matter(Especially from raw energy).

    http://en.wikipedia.org/wiki/Conservation_of_mass
     
  6. Jan 10, 2014 #5

    Nugatory

    User Avatar

    Staff: Mentor

    There's no such thing as "conservation of matter", but there is conservation of mass-energy and neither that nor any other conservation laws are violated by black holes.

    You drop something onto a black hole, you can't get it back out, but that doesn't mean it's not conserved. If I drop a penny into the deep ocean, it's gone forever - but that doesn't mean that a penny has been destroyed so there's one fewer penny in the world, it means that one of the pennies that had been in my pocket is now on the bottom of the ocean.
     
  7. Jan 10, 2014 #6

    PAllen

    User Avatar
    Science Advisor
    Gold Member

    Matter is created all the time from 'raw energy': an energetic photon passing near a charge readily produces particle-antiparticle pairs, which I always thought were matter.
     
  8. Jan 10, 2014 #7

    Drakkith

    User Avatar

    Staff: Mentor

    Take the annihilation of an electron and a positron into two gamma ray photons. The matter and antimatter no longer exists. That's pretty much the definition of "destroyed".

    Easy. Collide particles at a very high speed and watch as both matter and antimatter are created from the kinetic energy.
     
  9. Jan 11, 2014 #8

    atyy

    User Avatar
    Science Advisor

    There is a law which is violated in a semi-classical calculation by Hawking describing black hole evaporation. The law is the unitary evolution of the quantum wave function. This indicates that our understanding of quantum gravity is incomplete. Some have also suggested, including Hawking, that it may be that quantum mechanics itself fails.
     
  10. Jan 14, 2014 #9
    It is true that it is considered matter, closest thing to energy that IS matter is a Subatomic particle.
     
  11. Jan 14, 2014 #10

    Drakkith

    User Avatar

    Staff: Mentor

    Energy is a property of objects and systems of objects. A particle is no closer to being energy as it is closer to being momentum or velocity.
     
  12. Jan 15, 2014 #11
    THE BLACK HOLE WAR BY Leonard Susskind is a non mathematical discussion of black holes.

    BLACK HOLES AND TIME WARPS BY Kip Thorne is a bit more technical, traditional and comprehensive....very detailed; very little math. It's 99% black holes and 1% time warps....


    atyy
    I thought Hawking conceded to Susskind that Susskind was correct. Is there a source you can recommend so I can read more??


    The major 'conservation law' that was thought to be violated was the 'conservation of information' or the 'Information Loss Paradox' of black Holes. It turns out that most of the information of the universe resides in BH!.....like the supermassive BH at the heart of virtually all galaxies....

    What happens to information that 'disappears' into a black hole [BH]? Is it 'lost'?

    Susskind's work....
    Briefly, Unruh showed that thermal and quantum jitters get mixed up in an odd way. Susskind following d'Hooft's early work showed the information is encoded in subsequent Hawking radiation.

    Bits [information] is displayed on the stretched horizon, and later recovered even though a ‘copy’ is headed toward the singularity…Could someone grab the bit, jump in the BH and duplicate the information. No: the infalling bit arrives at the singularity in a finite, relatively short time. To recover even a single bit from the horizon, from outside, would supposedly take 1068 Years..a vastly longer period than the current age of the universe…to be recovered. [Don Page did this work.] [pg 264]

    An interesting view Susskind offers from string theory: long strings on the stretched horizon are subject to quantum jitters...and as a segment of string is bumped off, it is emitted as Hawking radiation.... in which BH information is scrambled/encoded.


    You can read summaries and other 'solutions' of the 'paradox' here:
    http://en.wikipedia.org/wiki/Information_loss_paradox
    http://en.wikipedia.org/wiki/Holographic_principle
     
  13. Jan 15, 2014 #12
    and is extremely close to all three! [maybe not velocity so much...]

    Viewing a particle as 'energy' is the QM view of the world we observe.

    In the QM view of the world, local quantum excitations [energy] of underlying [vacuum] quantum fields ARE particles. There is some debate in these forums as to whether particles or fields are more real. [see linked discussion below.] I like particles because that's what we detect.

    From a string theory perspective, the dimensional [11 of them] characteristics of spacetime constrain field [particle] fluctuations in different ways. So, for example a highly energetic particle is heavy. In a cosmological setting, right after the big bang, quantum fluctuations in the inflationary vacuum become quanta [particles] at super horizon scales.

    But considerable ambiguity about just what a particle 'is' remains.

    Good discussion here:
    What is a particle:
    https://www.physicsforums.com/showthread.php?t=386051
     
  14. Feb 8, 2014 #13
    energy = matter at the rate of c squared e=mc2 correct or am i missing something or matter = energy at the rate of square root of c ( interchangeable )
     
  15. Feb 8, 2014 #14

    Drakkith

    User Avatar

    Staff: Mentor

    The M in E=MC2 stands for mass, not matter.
     
  16. Feb 8, 2014 #15
    I was wrong thanks for correcting me. Replace matter with mass and it is correct the way i said it?
     
  17. Feb 8, 2014 #16

    Drakkith

    User Avatar

    Staff: Mentor

    Not really. There is no "rate" in the equation, only 2 variables and a constant. The equation means that the energy content of an object is equal to its mass times the speed of light squared.

    It also means that energy has mass. The mass of an object is equal to its energy content divided by the speed of light squared.
     
  18. Feb 8, 2014 #17

    Haelfix

    User Avatar
    Science Advisor

    The correct answer is that blackholes in general violate conservation laws associated with global symmetries. So for instance, baryon and lepton number are likely not conserved in general.

    Charges that are associated with long range gauge fields, like electric charge, however will stay conserved as this follows from generalizations from the no hair theorem..

    It is likely that a correct theory of blackholes will conserve unitarity as well.
     
  19. Mar 9, 2014 #18
    You might also want to take a look at black hole thermodynamics which are synonymous with the four laws of thermodynamics including the first law, conservation of energy.
     
  20. Mar 9, 2014 #19
    And energy is not a conserved quantity in General Relativity, but the Energy-momentum tensor is conserved locally.
     
  21. Mar 9, 2014 #20

    .... I don't see any function of creation only equivalence. I thought they were converted or transformed to 2 gamma rays?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Do black holes violate conservation laws?
Loading...