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

Origin of Black Holes

  1. Dec 9, 2008 #1
    Can BH be formed during star formation process? For instance, giant gas cloud or several collided clouds. In this case, can BH be created right after BB? Thank you.
  2. jcsd
  3. Dec 10, 2008 #2

    George Jones

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Because of small fluctuations of density of the primordial soup, it is possible that small black holes formed shortly after the Big Bang.
  4. Dec 10, 2008 #3
    Clouds of gas won't form a black hole all by themselves. It takes a whole lot of force to crush gaseous matter into a small enough space that a black hole is formed. With the possible exception mentioned by George Jones, all black holes of appreciable size would be the result of collapsed dead stars. I suppose extremely high energy collisions could form black holes, but this isn't something I imagine happens very often in a giant cloud of gas.
  5. Dec 10, 2008 #4

    George Jones

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

  6. Dec 12, 2008 #5
    I'm thinking the force, gravity, is always present. Since any type of matter can be used to "make" a BH, probability of BH formation was significantly higher in the "beginning of time" due to higher matter concentration.
  7. Dec 13, 2008 #6
    G'day from the land of ozzzzz

    People talk about as if there was a start or a origin to the universe.

    Than they apply conditions of how black holes can form.

    There is no need to do that.

    The conditions occur ongoing.

    The processes during a supernova creates excess neutrons via the entanglement of electromagnetic fields a property of plasma double layers. This process compacts Neutrons to the core of the Neutron Star.

    If there is suficient matter, theoretically the next stage, Neutrons break down to quarks again via entanglement of the EM fields compacting quarks. If sufficient trapping horizons are formed, the core becomes the so called black hole entrapping EMR, making it look like a black hole.

    Experiments with Z-pinch dynamics on earth are very promissing to expalin such processes.

    No magic no ad hoc ideas to make it work.
  8. Dec 17, 2008 #7
    I'm pretty sure we're talking about Black Holes forming from clouds of gas, not from Supernovas...
  9. Dec 17, 2008 #8
    I would think that, given the amount of power during the collision, a black hole may be able to form...
  10. Dec 18, 2008 #9
    G'day from the land of ozzzz

    The progressive formation of a black hole is proceeded by the formation of a Neutron Matrix, than if matter is sufficient the compaction proceeds to a high density degenerate matter that is able to form the Gravitaional/magnetic fields that are able to hold back EMR from escaping.

    As formation from clouds, the process would take Gyrs to form without a gravity sink.

    Maybe you should research the formation of black holes. Knowing where stellar black forms and how through merging develop into monsters.

    18 Billion Suns -A Galaxy Classic: Biggest Black Hole in Universe Discovered—and it’s BIG

    A universal constraint between charge and rotation rate for degenerate black holes surrounded by matter
    Feb 2008


    Equilibrium Configurations of Degenerate Fermionic Dark Matter and the Black Hole Mass Hierarchy
    00 2008

    We propose degenerate fermionic dark matter to explain the flat-top density profile of the cluster A1689 recently observed.

    Symmetry Properties of Black Holes in Higher Dimensional General Relativity
    00 2008


    We discuss symmetry properties of black holes in general relativity---known as black hole rigidity---of which basic assertion is that the event horizon of an asymptotically flat, stationary black hole with certain matter fields must be a Killing horizon and is rephrased (combined together with staticity results) that such a black hole must be either static, or axisymmetric. A precise formulation of the rigidity theorem for black holes with non-degenerate event horizon in arbitrary spacetime dimensions has been recently made by Hollands, Wald and the present author. [Hollands, S., Ishibashi, A. and Wald, R. M., Commun. Math. Phys. 271 (2007), 699.] In our formulation, no assumptions concerning the topology of cross-sections of event horizon (other than the compactness) are made. Therefore, different from Hawking's original proof given in 4-dimensions, our proof applies also to non-spherical black holes, which are known to occur in higher dimensions but not in 4-dimensions.
  11. Jan 15, 2009 #10
    A black hole forms when any object reaches a certain critical density, and its gravity causes it to collapse to an almost infinitely small pinpoint. Stellar-mass black holes form when a massive star can no longer produce energy in its core. With the radiation from its nuclear reactions to keep the star "puffed up," gravity causes the core to collapse. The star's outer layers may blast away into space, or they may fall into the black hole to make it heavier.

    I'm with sundance for this one.
  12. Jan 16, 2009 #11


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    There seems to be some confusion in this post ...

    For starters, the word 'degenerate' has at least two, quite different meanings!

    In the Ansorg and Pfister (2008) paper, and the Ishibashi (2008), 'degenerate' refers to a mathematical feature of certain GR or GR+ solutions; it's not at all clear that it has any physical meaning (other than, perhaps, a way of avoiding singularities ... which have no observable phenomenology anyway!)

    In the Nakajima and Morikawa (2008) one, 'degenerate' refers to a quantum state of hypothetical particles (CDM particles as fermions), though I have not been able to get the paper, so I can't tell how this relates to "The Black Hole Mass Hierarchy".
  13. Jan 17, 2009 #12


    User Avatar
    Science Advisor
    Gold Member
    2015 Award

    Black hole formation is still an enigma. It is unclear if this is even a possible outcome for your garden variety dying star [think recoil]. My suspicion is most, if not all, black holes formed in the very early universe by means not yet understood.
  14. Jan 17, 2009 #13
    Hello Chronas / Nereid

    There are various meanings to Black Holes. The strict definition that was held years ago with a singularity and an event horizon and that nothing can escape in my opinion cannot exist.

    But! a compact object that has at least a matrix of Neutrons forming trapping horizons maybe able to form the so called black hole. The ability for EMR to escape the vector fields during the process of it being sucked into the so called BH is very slim. But! ongoing research particularly in Z-pinch experiments has added light to the ability of the plasma within the core of the compact object to form a vortex made from electromagnetic gravitational waves that is able to eject matter from the core, so much that the stability can last for millions of years from the same spot. If the jet was created during the accretion in the area of the disc, the stability would be in question. Although jets form in these areas they aid in adding matter back to the halo of the galaxy core envelope rejuvinating star formation in these areas. The main function of the main jet is to reform the galaxy and also affecting other galaxies.

    Yes our understanding is that nothing can escape a BH. But! since I do not agree with this, I can start to understand BHs a little better.

    A Neutron matrix is thought to be the final compact matter that is held together via Neutron repulsion.
    The more compact version being the Neutrons merging an over coming the Neutron repulsion and possibly form quark matter leading to Neutrino matter which is very theoretical but ! ultra dense. Our sun could compact down to a few mm.

    As far as early universe is concerned, thats based on the BBT, which is only a theory. We cannot assume it to be correct than proceed to make it a reality.

    I'd rather see the phases of evolution as stages and accordingly date them as so. We can trace star formation and rejuvination and we can observe the diffferent forms of galaxies and explain their form that is directly related to the size and activity of the central compact core. That means compact cores(BH) can alter in mass and size meaning losing and gaining matter.


    This is not as simple as it looks, we are still at the footsteps of research.
  15. Jan 17, 2009 #14
    I thought a BH can collapse to a certain radius e.g. the Schwarzschild radius. Certainly not to an infinitely small pinpoint (a singularity). The smallest BH I can think off is a Planck-particle with its Planck-density and Planck-radius. Maybe only the pit or the core within a BH can have Planckdensity?? A Schwarzschild radius is proportional to the mass of the BH and normally the BH's average density is by far lower than the Planck-density.
  16. Jan 17, 2009 #15
    Hello Hurk4

    Theory and reality are two diffferent issues.

    Singulaity cannot exist as an infinite point. So in a way a black hole cannot exist in its true theoretical form.

    As for the collapse of matter. Its better to understand how it collapses and the mechanisms. That is apply physics to the matter rather than some form of theory based on ad hoc ideas.

    As for event horizons, no one has ever seen one, not even the so called black hole.

    But! still there are many that would stake their lives that they exist.
  17. Jan 17, 2009 #16
    I don't think so.Because black holes are formed only when the degeneracy pressure is not enough to withstand the gravity and thus a gravitational collapse occurs.But actually stars are formed only because of the gravitational collapse of a giant molecular cloud.

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Origin of Black Holes
  1. On Black Holes (Replies: 0)

  2. Black holes (Replies: 17)

  3. Black Holes (Replies: 13)