Black Holes are not actually "holes".
Discussion
OK, to answer some of the questions raised, some radiation is sufficiently massive and energetic enough to escape the immediate pull over the event horizon, and can do so right up to that moment, a few Kms above the surface of the star itself, where the gravitational pull is sufficient to overcome the energy imparted by the moment of crushing.
Think of the manner that a sheet of glass shatters, some tiny shards of the glass fly off at great speed and energy.
The next misconception is that Black Holes stars will finally consume the Cosmos, this can't happen, it was thought to be the case until quite recently, at some point all BHSs will encounter Dark Matter and in doing this a cap on the possible maximum size is found.
There is also a point further up the scale of things where effectively a BHS is subject to sufficient Cosmological forces to effectively cap any further expansion and the star itself becomes radiant, it then is on the road to annihilation of its own existence as a BHS, but that stops also before they disappear and they begin to grow again, it's a cycle, an immensely long one but a cycle none the less.
Think of the manner that a sheet of glass shatters, some tiny shards of the glass fly off at great speed and energy.
The next misconception is that Black Holes stars will finally consume the Cosmos, this can't happen, it was thought to be the case until quite recently, at some point all BHSs will encounter Dark Matter and in doing this a cap on the possible maximum size is found.
There is also a point further up the scale of things where effectively a BHS is subject to sufficient Cosmological forces to effectively cap any further expansion and the star itself becomes radiant, it then is on the road to annihilation of its own existence as a BHS, but that stops also before they disappear and they begin to grow again, it's a cycle, an immensely long one but a cycle none the less.
einsign said:
TheHeretic said:
According to Hawking Radiation, a black hole will emit particles as well as draw them in. No idea how much, just something I heard someone talk about a while ago.
But how does it emit particles if nothing can escape, not even light?Gene Vincent said:
They are called correctly 'Black Hole Stars' they are usually a sphere the same diameter of Paris, ie very damned small, hot and dense (like the Napolean?) but they have a huge influence on the surrounding Cosmos and that is the 'Black Hole' that surrounds it and that's huge and light can't get out, so you have an event horizon, the point at which the light can't, this is odd and is really the only item we can study as we can get any information at all out of 'Paris' (bureaucracy eh!) so we use the term Black Hole.
We only study Black Hole Stars by the proxy of Maths, it works to a surprising degree of accuracy, accurate enough to even compensate for a tiny amount of evaporation through radiation in the final check sum.
We have a damned fine handle on them, they are odd but not even vaguely mysterious.
The Black Hole Star is a Gravitational Singularity but not a 'Singularity' without the prior clause as that term is reserved for the point from which this Cosmos came into being.
Somewhere in the Milky Way (not the confection) there is a big one or more likely one massive one and a tiny one and their death dance around each other has some additional impetus to the rotation of our Galaxy that we call the Milky Way.
I'm suddenly overwhelmed with the craving for sweet confections... odd world eh!
That's Sweet Gene Vincent.We only study Black Hole Stars by the proxy of Maths, it works to a surprising degree of accuracy, accurate enough to even compensate for a tiny amount of evaporation through radiation in the final check sum.
We have a damned fine handle on them, they are odd but not even vaguely mysterious.
The Black Hole Star is a Gravitational Singularity but not a 'Singularity' without the prior clause as that term is reserved for the point from which this Cosmos came into being.
Somewhere in the Milky Way (not the confection) there is a big one or more likely one massive one and a tiny one and their death dance around each other has some additional impetus to the rotation of our Galaxy that we call the Milky Way.
I'm suddenly overwhelmed with the craving for sweet confections... odd world eh!
Edited by Gene Vincent on Wednesday 9th January 00:52
Gene Vincent said:
In simple terms they blink out of existence to you the observer from a safe distance....
......But a gravitational singularity is an infinite absorber of light and any information it might be able to convey, it will grow is size not by absorbing light (although it does a little, following the Reissner-Nordstrom research) but by acquiring further mass, for example if your space craft fell into and finally was crushed and added to the mass of the Black Hole Star then at the same time the event Horizon would expand marginally.
Can one measure the size of a BHS by using the relationship of the amount an object passing by the BHS fades, and by knowing the objects distance from the BHS?......But a gravitational singularity is an infinite absorber of light and any information it might be able to convey, it will grow is size not by absorbing light (although it does a little, following the Reissner-Nordstrom research) but by acquiring further mass, for example if your space craft fell into and finally was crushed and added to the mass of the Black Hole Star then at the same time the event Horizon would expand marginally.
How about Ultra Mass? As the OP said, they're not holes.
Ian Dury would be proud you saw the allusion.
We measure the Star by the size of it Event horizon and we measure the Event Horizon in the cunning way you have outlined.
The EH is really invisible, its black and it hides in space which is also black but there are stars in front and behind and we have maths for that and maths for the manner of gravitational collapse and mass from the path stars take in their lifetimes.
Thankfully our nearest is a long way away and this good for our prospects but a pain for science.
A BHS will always drag down the neighbourhood if it gets a chance.
We measure the Star by the size of it Event horizon and we measure the Event Horizon in the cunning way you have outlined.
The EH is really invisible, its black and it hides in space which is also black but there are stars in front and behind and we have maths for that and maths for the manner of gravitational collapse and mass from the path stars take in their lifetimes.
Thankfully our nearest is a long way away and this good for our prospects but a pain for science.
A BHS will always drag down the neighbourhood if it gets a chance.
einsign said:
Black holes formed by stars etc gathering matter and eventually having so much mass that light cannot escape, fair enough but this does not make it a "hole".
Why are they not called Black Stars?
As really heavy floaty sucky thing while accurate doesn't sound as professional Why are they not called Black Stars?
Actually, being pedantic, if you can't describe a Black Hole as black then we are really f
ked on the description front aren't we!
It is in fact the blackest thing in the Cosmos, almost no radiation leaves it, it is the very acme and zenith of black, other blacks go pale in jealousy at its utter blackness, the Black Prince is de-throned and Black Beauty is an Albino Donkey in comparison to the Black of a Black Hole, even the word black is not really black enough to adequately describe the total blackness of a Black Hole, it's black in ways that black simply is not able to convey, think of the blackest thing you've ever thought of and that is pure gleaming white in comparison, other words are not enough either, nero, schwarz, sort, zwart, musta, noir, fekete, czarny all are black but even all together they are not enough of the black stuff to be black enough.
It's sorta black, but blacker.
ked on the description front aren't we!It is in fact the blackest thing in the Cosmos, almost no radiation leaves it, it is the very acme and zenith of black, other blacks go pale in jealousy at its utter blackness, the Black Prince is de-throned and Black Beauty is an Albino Donkey in comparison to the Black of a Black Hole, even the word black is not really black enough to adequately describe the total blackness of a Black Hole, it's black in ways that black simply is not able to convey, think of the blackest thing you've ever thought of and that is pure gleaming white in comparison, other words are not enough either, nero, schwarz, sort, zwart, musta, noir, fekete, czarny all are black but even all together they are not enough of the black stuff to be black enough.
It's sorta black, but blacker.
Gene Vincent said:
Actually, being pedantic, if you can't describe a Black Hole as black then we are really fked on the description front aren't we!
It is in fact the blackest thing in the Cosmos, almost no radiation leaves it, it is the very acme and zenith of black, other blacks go pale in jealousy at its utter blackness, the Black Prince is de-throned and Black Beauty is an Albino Donkey in comparison to the Black of a Black Hole, even the word black is not really black enough to adequately describe the total blackness of a Black Hole, it's black in ways that black simply is not able to convey, think of the blackest thing you've ever thought of and that is pure gleaming white in comparison, other words are not enough either, nero, schwarz, sort, zwart, musta, noir, fekete, czarny all are black but even all together they are not enough of the black stuff to be black enough.
It's sorta black, but blacker.
If one accepts that a black hole starts at the event horizon, a questionable premise it has to be said, then logic is not on your side I'm afraid.ked on the description front aren't we!It is in fact the blackest thing in the Cosmos, almost no radiation leaves it, it is the very acme and zenith of black, other blacks go pale in jealousy at its utter blackness, the Black Prince is de-throned and Black Beauty is an Albino Donkey in comparison to the Black of a Black Hole, even the word black is not really black enough to adequately describe the total blackness of a Black Hole, it's black in ways that black simply is not able to convey, think of the blackest thing you've ever thought of and that is pure gleaming white in comparison, other words are not enough either, nero, schwarz, sort, zwart, musta, noir, fekete, czarny all are black but even all together they are not enough of the black stuff to be black enough.
It's sorta black, but blacker.
Can you see it? If the answer is no then it is invisible so its appearance cannot be described as it hasn't got one. If the answer is yes then it cannot be invisible.
There is no light emmenating from it - on the asusmption that the fuzziness is not within our range of vision - but that does not mean the term black can be used. Invisible is the only option as we need light to see an object.
We can, of course, see it's effects of other objects, such as, for instance, gas from a star that wandered too near, but that is the gas not the black hole.
On the other hand, I'm happy with the idea of a hole, something which things fall into and do not come out of: the classic way of describing Einsteinian space as a rubber surface pulled fairly tight with heavy objects on it. I know it is 'wrong' to think of it that way as it is nothing more than a model, but the difference between quite heavy and an invbisible hole is easily domonstrated.
It all comes down to using language to describe something which can only be written in mathematics.
So black hole is a perfectly reasonable term to use as it is a name and not a description.
The definition of black is the absence of radiated energy, that is what things that are black are, they absorb all EMR and reflect as little as possible, the less they radiate the blacker they are, a Black Hole is defined by its EH and it really is the blackest thing in the Cosmos because by the definition of black, that is what it is, very, very black.
Derek, a Black Hole really is black.
Derek, a Black Hole really is black.
Do you get crushed in a black hole? I thought you got pulled to pieces as the parts of you closer to the singularity experience a significantly larger gravitational pull then those further away, and so accelerate towards the singularity, in effect stretching you out like a piece of gum.
Flibble said:
Do you get crushed in a black hole? I thought you got pulled to pieces as the parts of you closer to the singularity experience a significantly larger gravitational pull then those further away, and so accelerate towards the singularity, in effect stretching you out like a piece of gum.
Yes.This idea of being stretched is not quite as it seems.
At about 5km above the star itself you will be travelling just short of the speed of light.
This where many people, scientists too, don't quite grasp things correctly.
So at that critical point 5kms up you are accelerated just 0.3m/sec and your toes are effected first and your head last but you are already travelling at 299,792.158m/sec, but lets make this simple shall we.
0.3/300,000 = 1/1,000,000
Lets say you are big, strapping, redbull lobbing, athletically built company director and 2m tall.
So for your head to reach the position that your feet where at any given moment takes just 1/150,000 of a second.
So the period of the 'stretch' is for approximately 1/150,000 sec and that stretch occurs at 0.3m/sec so you are stretched by 3/500,000ths of your total length before being crushed to about 1/10,000,000th of your previous size.
So our average PHer is stretched by just 6/500,000ths of a metre and is then in 1/150,000th of a second our PHer is crushed to 1/500,000th of a millimetre.
The 'stretch' does occur, but it is of no consequence and would be unnoticeable.
Edited by Gene Vincent on Saturday 12th January 09:14
Great to see you back Gene, I find your posts and Matt Strassler's Of Particular Significance blog the best resources online for me! Especially your posts helping people to visualise the science on a quantum level, which I would guess is the hardest part for most at my level to grasp.
Perhaps you could recommend some further reading for me? I have read all of Prof. Brian Cox's books, most of Hawking but find Mitchio Kaku a little too wandering for my liking so far...
Anyway, thanks for your efforts and apologies if this is considered a thread hijack!
All the best for the new year.
Perhaps you could recommend some further reading for me? I have read all of Prof. Brian Cox's books, most of Hawking but find Mitchio Kaku a little too wandering for my liking so far...
Anyway, thanks for your efforts and apologies if this is considered a thread hijack!
All the best for the new year.
Edited by Firebox7 on Saturday 12th January 13:37
Firebox7 said:
Great to see you back Gene, I find your posts and the Of Particular Significance blog the best resources online for me! Especially your posts helping people to visualise the science on a quantum level, which I would guess is the hardest part for most at my level to grasp.
Perhaps you could recommend some further reading for me? I have read all of Prof. Brian Cox's books, most of Hawking but find Mitchio Kaku a little to wandering for my liking so far...
Anyway, thanks for your efforts and apologies if this is considered a thread hijack!
All the best for the new year.
Top lurking!Perhaps you could recommend some further reading for me? I have read all of Prof. Brian Cox's books, most of Hawking but find Mitchio Kaku a little to wandering for my liking so far...
Anyway, thanks for your efforts and apologies if this is considered a thread hijack!
All the best for the new year.
Thanks for the compliments, much appreciated.
In my opinion once you've read a bit of those books, you have to look at yourself and decide if you want to take the next step and there is no getting away from the fact that maths is the inevitable place to go, so a good book on maths that takes up where you left off previously, but aim for any that deal with Cosmology and its Maths it's a bit of hard work, a lot actually, but the limit of understanding is finally defined by maths. Otherwise just read what I put on here and take some of the words and hit Wiki and sometimes there are references to good books but each time the stumbling block is your own maths.
All the best to you and yours for the New Year.
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