Discussion
I was watching a documentary on Space last night and a fair chunk of it was about black holes.
Space fascinates me and always makes me wonder but I've never got round to really reading up on anything into it.
But one thing really confused me, and that was the computer generated 'model' of a black hole tearing apart a star. Now, to begin with, the whole implosion of a giant star to form a black hole baffled me andI tried to get my head around the question of "where does all the mass go?". Is it a case of the core shrinks on itself but creates energy/heat whilst it's doing it, which is how it can do what it does.
Then, after the supernova, as I understand it, if the star's remaining mass is greater than three times the mass of the Sun, the star contracts tremendously and becomes a black hole, I read that but I think I understand the basis of it.
What I don't understand is when a black hole is 'feeding' on something, where does the mass of that something go? Is it a similar vein to that of the mass being 'eaten' creates and gives off an incredible amount of heat and that's where it all goes or.....
Forgive my ignorance but does anyone know?
>>> Edited by Graham.J on Thursday 3rd February 18:43
Space fascinates me and always makes me wonder but I've never got round to really reading up on anything into it.
But one thing really confused me, and that was the computer generated 'model' of a black hole tearing apart a star. Now, to begin with, the whole implosion of a giant star to form a black hole baffled me andI tried to get my head around the question of "where does all the mass go?". Is it a case of the core shrinks on itself but creates energy/heat whilst it's doing it, which is how it can do what it does.
Then, after the supernova, as I understand it, if the star's remaining mass is greater than three times the mass of the Sun, the star contracts tremendously and becomes a black hole, I read that but I think I understand the basis of it.
What I don't understand is when a black hole is 'feeding' on something, where does the mass of that something go? Is it a similar vein to that of the mass being 'eaten' creates and gives off an incredible amount of heat and that's where it all goes or.....
Forgive my ignorance but does anyone know?
>>> Edited by Graham.J on Thursday 3rd February 18:43
It rips a hole in the space/time continuum as the density becomes infinite (hence the escape velocity exceeds that of light). I think its properties are just charge and spin as well as the gravitational strength which must be different as the event horizons/s'child radii are different. I heard.
The deal is that different conformations of matter exist under pressure, ie neutron stars are preferable to proton/electron stars and take up less space. It is energetically favourable. As pressure increases, the quark structure of the neutrons breaks down and takes up less space. In the end the whole thing collapses infinately upon itself and ceases to exist in a measurable way.
>> Edited by love machine on Thursday 3rd February 18:43
The deal is that different conformations of matter exist under pressure, ie neutron stars are preferable to proton/electron stars and take up less space. It is energetically favourable. As pressure increases, the quark structure of the neutrons breaks down and takes up less space. In the end the whole thing collapses infinately upon itself and ceases to exist in a measurable way.
>> Edited by love machine on Thursday 3rd February 18:43
groucho said:That's how I always thought of it. Big bang = outwards, Black Hole = inwards.
I always thought that a black hole is like the opposite of the big bang.
I'm not trying to get my head around the whole universe because, quite frankly that's beyond me but there are plenty of black hole's about and I'm trying to work it all out.
The whole big bang thing baffles me as well, if it was a big bang, would the universe not be of relative proportions (as it's a vacuum so nothing like wind resistance or something to alter the path of the matter) as opposed to the 'horseshoe' or 'saddle' shape we're lead to believe it is.
>> Edited by Graham.J on Thursday 3rd February 18:56
>> Edited by Graham.J on Thursday 3rd February 18:56
JustTheTip said:
The thing I fail to comprehend is the fact that prior to the big bang, there was nothing. So where did the energy for the bang come from??? A basic law of physics states you can't get something for nothing, so it must have come from somewhere.
I often wondered that.
I don't believe the God version and a thought just sprung into my mind that maybe the universe as we know it was created as part of or from a result of something else unimaginable.
The mass doesn't dissapear; it justs gets added to the other matter that is already falling into the black hole. A black hole is a region of space that has a particular property; it's not an "object" in the sense that a star or a planet is an object. The property is that the escape velocity from that region of space is higher than the speed of light. This means that inside that region of space there is a hell of a lot of matter, but it isn't in some defined shape or other. It is all just falling in towards the centre of the region of space. If a bit more matter falls into the black hole, it joins the rest of the matter that is in there already falling towards the centre of the black hole.
JustTheTip said:
The thing I fail to comprehend is the fact that prior to the big bang, there was nothing. So where did the energy for the bang come from??? A basic law of physics states you can't get something for nothing, so it must have come from somewhere.
Got to be very careful with what you mean by "before". Time itself is "just" part of the geometry of the universe. If there isn't a universe, then time doesn't exist either. So if the big bang is the creation of the universe, then you can't ask "what happened before the big bang" because there was no before.
editted to add the same arguement also means that thinking about the big bang as a "creation" is a bit duff as well.
>> Edited by ATG on Thursday 3rd February 19:06
As I understand it (fairly poorly, but my wheelchair is faster than Hawking's 
), as an object reaches the event horizon, the light escaping from it is gradually "slowed down" the closer it gets until at the actual horizon the light "stops" and an observer watching it would see the object appear to completely stop, while it actually carried on plunging into the black hole along with "it's light".
If so......
Considering the amount of "stuff" dragged into yer average black hole, which would all be permanantly frozen at the event horizon, why isn't it a white hole?
), as an object reaches the event horizon, the light escaping from it is gradually "slowed down" the closer it gets until at the actual horizon the light "stops" and an observer watching it would see the object appear to completely stop, while it actually carried on plunging into the black hole along with "it's light". If so......
Considering the amount of "stuff" dragged into yer average black hole, which would all be permanantly frozen at the event horizon, why isn't it a white hole?
ATG said:
The thing I fail to comprehend is the fact that prior to the big bang, there was nothing. So where did the energy for the bang come from??? A basic law of physics states you can't get something for nothing, so it must have come from somewhere.
Got to be very careful with what you mean by "before". Time itself is "just" part of the geometry of the universe. If there isn't a universe, then time doesn't exist either. So if the big bang is the creation of the universe, then you can't ask "what happened before the big bang" because there was no before.
editted to add the same arguement also means that thinking about the big bang as a "creation" is a bit duff as well.
>> Edited by ATG on Thursday 3rd February 19:06
A little while back I was in bed thinking about the nature of the universe and time and it occured to me that if one were able to "step sideways" outside of time you would be able to look back and "see" the whole universe a singularity - the entire universe as one entity, in which everything happened at once. Time is like a vapour trail cast by a jet - when you're riding along in the plane you can't see it ahead of you but you can see a bit of it by looking out the back. But if you're standing on the ground you can see the whole thing, right across the sky... and all the vapour trails build up until you just see one great big vapour trail. Then you go home before you fall asleep.
Sorry
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