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Black Holes

  • 14-04-2020 12:14am
    #1
    timsey tiger
    Registered Users Posts: 1,768 ✭✭✭


    Why are black holes called black holes, shouldn't they be called black gulls or even black wholes.:o


Comments

  • #2
    Fourier
    Registered Users Posts: 10,558 ✭✭✭✭Fourier


    timsey tiger wrote: »
    Why are black holes called black holes, shouldn't they be called black gulls or even black wholes.:o
    I'm not sure I understand the question, but they're called black holes because they behave like holes in spacetime, i.e. things fall into them and can't get out.

    I'm not sure why they'd be called gulls or wholes.


  • #3
    timsey tiger
    Registered Users Posts: 1,768 ✭✭✭timsey tiger


    That was a typo I meant fulls.


  • #4
    Hairy Japanese BASTARDS!
    Closed Accounts Posts: 443 ✭✭Hairy Japanese BASTARDS!


    It's a racist name and must be changed to holes of colour.

    #BLM


  • #5
    Bit cynical
    Registered Users Posts: 2,338 ✭✭✭Bit cynical


    timsey tiger wrote: »
    That was a typo I meant fulls.
    If they were full there would be no room left in them. But there is always room for more in a black hole.


  • #6
    timsey tiger
    Registered Users Posts: 1,768 ✭✭✭timsey tiger


    Bit cynical wrote: »
    If they were full there would be no room left in them. But there is always room for more in a black hole.

    I would contend that there is no room in them, everything added just makes them bigger, like a snowball rolling down a hill.


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  • #7
    CalamariFritti
    Registered Users Posts: 5,397 ✭✭✭CalamariFritti


    I understand a black hole is a tiny thing with immense gravity. Like a neutron star on steroids. The gravity is so immense that not even photons (light) can escape it. Hence we will never see any light reflecting off a black hole and therefore it appears black. We only recognise black holes due to their nothingness if you like. The fact that there is literally nothing to see. Also due to its immense gravity it effectively acts like a sink or a hole to everything including light. It's quite aptly named in my opinion.


  • #8
    TheBoyConor
    Closed Accounts Posts: 3,292 ✭✭✭TheBoyConor


    black because they were originally believed to not emit any light. But that is now know not to be the case. They emit hawking radiation, so they are not fully black really.

    Black holes however can at times be the brightest objects in the universe. Quasars and blazars are when ultramassive black holes are feasting on matter and the material circling the great cosmic plughole gets so stupendously superheated that it shines brighter than the rest of the host galaxy combined. But the thing there is it is not the black hole itself that is emitting all that light - it is the material sprialling into, but not quite yet inside, the black hole's event horizon.

    A very awe inspiring relic of a long dormant black hole/quasar is Hanney's Voorwherp. It is a light echo, millions of years ago a quasar lit up a huge cloud of cosmic gas. The quasar went quiet but the light from the illuminated cloud has taken a longer route to reach us, so even thought the quasar is now dark, we can still see the illuminated cloud many millions of years later.

    Hole because because shít falls in and is never seen again. More technically, gravity bends space time so much inside the event horizon that the curvature of space becomes infinite. Hard to understand that, but what I get from it that things are so jacked up by the extreme gravity that space no longer acts like space and basically is a rip or hole.

    Some black holes are tiny. However, others a truly enormous. I cannot think of any names but there are some super and ultamassive black holes that have many many billions of solar masses inside them and if they were centred in the location of the sun, the event horizon would extend out beyond the orbit of Jupiter.

    We in the Milky way have our own supermassive black hole, Saggitarius A*. If that were to turn into a quasar, it could sterilise the whole galaxy.


  • #9
    timsey tiger
    Registered Users Posts: 1,768 ✭✭✭timsey tiger


    Oh dear, this did not develop like I thought it might (my bad) I thought the emoji would indicate that op was not serious.

    Thanks for the explanations on where the name black hole comes from I guess, but you could have just linked to wikipedia or an Tyson youtube.


  • #10
    TheBoyConor
    Closed Accounts Posts: 3,292 ✭✭✭TheBoyConor


    If you were only messing then why didn't you ask in AH rather than Mathematics, Physics & Chemistry?


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