black holes

freddiegrubb
freddiegrubb Posts: 448
edited June 2013 in The cake stop
Watched the Horizon prog. last night & some black holes are er black but these holes are on a diet, other holes are feeding holes & guess what -they emit vast quantities of light.The bods reckon that as they suck rotating matter/gas in, the friction superheats & = light.Now friction reqs. at least 2 surfaces to rub on each other, so where does the other come from if space is a vacuum? Discuss at your leisure.

Comments

  • ballysmate
    ballysmate Posts: 15,921
    The area around the event horizon of a black hole is a sea of particles. Virtual particles appear and annihilate each other all the time. On earth, our everyday idea of a vacuum is no such thing at the sub atomic level.
  • finchy
    finchy Posts: 6,686
    ^^^ What he said. Basically, a true vacuum does not exist.

    http://en.wikipedia.org/wiki/Vacuum#Outer_space
  • Kerguelen
    Kerguelen Posts: 248
    @freddiegrub, it's the friction between the various gas molecules compressed into a small volume (accrection disc) by the high gravitational forces near the event horizon.

    @Ballysmate, that's Hawking radiation which is an entirely different thing caused by half a of a virtual particle/antiparticle pair escaping from just outside the event horizon.
  • ballysmate
    ballysmate Posts: 15,921
    Kerguelen wrote:
    @freddiegrub, it's the friction between the various gas molecules compressed into a small volume (accrection disc) by the high gravitational forces near the event horizon.

    @Ballysmate, that's Hawking radiation which is an entirely different thing caused by half a of a virtual particle/antiparticle pair escaping from just outside the event horizon.

    You are correct, The OP mentioned specifically black holes and vacuum.I am aware of Hawking radiation and how he postulated how black holes could 'evaporate' by the absorbing of anti particles. Particle/antiparticle pairs are created from 'nothing', and sometimes the antiparticle is captured beyond the event horizon before anihilation has occurred. I was trying to show, albeit clumsily that his idea of any vacuum was mistaken.
  • freddiegrubb
    freddiegrubb Posts: 448
    Keep it up lads , we're getting very deep here--ELSIE TANNER calm down you old fool.
  • john1967
    john1967 Posts: 366
    In space no one can eat ice cream.
  • meursault
    meursault Posts: 1,433
    It's a lot of theory. We don't even know what gravity is, just that it is.
    Superstition sets the whole world in flames; philosophy quenches them.

    Voltaire
  • skyd0g
    skyd0g Posts: 2,540
    black holes suck.
    Cycling weakly