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

Black hole might crunch the many planets into marble-sized spheres

  1. Jun 28, 2004 #1
    If the black hole has infinite capacity to store mass,why,in a case of the sucking up of the sun,why would their(crudely described)sunny-side up expel huge jet streams of flames and heat? Cant they absorb heat energy and UV since they have capacity to collect mass?

    If it is possible the Black hole might crunch the many planets into marble-sized spheres,but a wormhole...? :eek:
  2. jcsd
  3. Jun 28, 2004 #2


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    The big jets and so on happen outside the boundary of the black hole, the so called event horizon. Anything that goes through the event horizon disapppears and no news ever comes back about it. But close to the event horizon, spacetime is strongly curved, and this provides the energy for lots of visible action, not only jets but swooping stars and radiating clouds of gas.
  4. Jun 28, 2004 #3
    Jet Expulsion from Supermassive Black Hole Galactic Binaries

    Regarding, Jet Expulsion from Supermassive Black Hole Galactic Binaries;

    From a Supermassive Black Hole/Galactic Core;

  5. Jul 13, 2004 #4
    Im not sure black holes eject anything apart from HAWKING RADIATION.
    could you be thinking of a hypernova expelling jets of gamma rays?
  6. Jul 13, 2004 #5
    black holes do eject very stong gamma rays. This is because at the event horizon, there is virtual/real particle production, and some of these particles do escape. According to stephen hawking, these gamma rays are very intence, and cannot be detected because of too much rediation from other sources in the universe.
  7. Jul 14, 2004 #6


    User Avatar
    Staff Emeritus
    Gold Member
    Dearly Missed

    BTW, these particles are not "ejected from the black hole". They are formed in the space just outside the event horizon, where things can still escape.
  8. Jul 14, 2004 #7


    User Avatar
    Science Advisor

    The more massive the BH, the less there is virtual particle production. The sites posted and most descriptions will tell you that the EM radiation (gamma-to-radio) and especially the jets are from heated accretion matter near the event horizon, like selfAdjoint said.

    Just read the caption under the graphic at:
    that Nommos Prime posted.
  9. Jul 18, 2004 #8
    Critical Criterion...

    Classical blackbody radiation is dependent upon any radiating body being warmer than its natural environment.

    The environmental temperature of the Universe:
    [tex]T_b = 2.726 K[/tex] - (COBE 1990)

    The Kerr Temperature for a BH with angular momentum is:
    [tex]T_k = \frac{\hbar c^3}{K_o G M_k}[/tex]

    [tex]K_o[/tex] - Boltzmann's constant

    For any object to radiate, its natural temperature must exceed the temperature of its natural environment.

    [tex]T_k \geq T_b[/tex]

    Orion1-Kerr Critical Mass for BH thermodynamics:
    [tex]M_b = \frac{\hbar c^3}{K_o G T_b}[/tex]

    BH Masses which exceed this mass do not radiate, but actually increase in mass instead. However note that such a mass could eventually radiate when the Universe's natural environmental temperature becomes cool enough.

    Described here, a Kerr BH mass must be 5.285 times smaller than Terra's mass, in order to radiate.
    [tex]M_b = 1.131*10^{24} kg[/tex]

    Last edited: Jul 18, 2004
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Black hole might crunch the many planets into marble-sized spheres
  1. Black hole size (Replies: 9)

  2. Sizes of black holes (Replies: 5)