Answer my science question

ChroniC

ChroniC

ChroniC

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18 Oct 2002
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This may well be two advanced for an answer I'll understand, but I am curious if anyone knows.
Question is.. What proof/math is there that a black hole is destructive. The physics says it forms a singularity where all matter that enters is destroyed. (or there abouts)
However I cannot understand or find any information on why this is the case.
Why for instance is it not logical to assume instead that a black sphere is formed, which still has mass and shape but light cannot escape due to the extreme mavity.
How can a blackhole grow if matter is destroyed, or is the word "hole" to ambiguous?

Anyone?
 
I'm far from a physics whizz and it's been a couple of years since I've read any books on it (Krauss, Hawking, Cox). But I thought black holes were initially proposed by Einsteins theory of general relativity? Then other physicists/cosmologists/other'ists described the conditions and math behind the different types of black holes using Einsteins work.

I thought matter wasn't destroyed but condensed so much that whatever 'was' appeared to be destroyed? Again I could quite easily be wrong here.

Side note: patiently waiting for Krauss' new book next month :D
 
It's two advanced for me but from what I remember matter wasn't destroyed but compressed and that's what gave it it's size and ability to grow.
 
Then hole is a relatively poor choice for words of which something that becomes super massive would end up being a large sphere shape. Hence my confusion on why they're not call black stars or black planets etc.
Or is the matter shrunk so massively that it never grows to bigger than the size of the atoms it once contained.
 
What you describe in your last sentence is a singularity. Read up a little about what happens at and beyond the event horizon, especially with reference to spaghettification. The idea is a combination of the fact that the different parts of an object are being pulled to a single place, and therefore will converge along a single line, and that the closest part of an object to a black hole gets pulled with greater force than the part further away, so it gets pulled to a greater extent before the bits further away do. This means the object would get stretched out, like spaghetti. Pretty destructive! If you mean does the matter get "destroyed", as in, turned in to energy, then no.
 
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My 2p. The singularity is a product of mathematics and cannot actually exist. Essentially the maths and laws of physics break down because the logical conclusion of the maths is a singularity with zero volume, infinite density and infinite mavity.

This means we don't really know what is going on as we don't have a mathematical model to describe the behaviour.

Regarding the shape, it has always annoyed me that in books and on TV a black hole is always depicted as flat disc. I believe it would actually be a perfect sphere.
 
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danlightbulb said:
My 2p. The singularity is a product of mathematics and cannot actually exist. Essentially the maths and laws of physics break down because the logical conclusion of the maths is a singularity with zero volume, infinite density and infinite mavity.

This means we don't really know what is going on as we don't have a mathematical model to describe the behaviour.

Regarding the shape, it has always annoyed me that in books and on TV a black hole is always depicted as flat disc. I believe it would actually be a perfect sphere.
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not really it absorbs so much light it would appear as a flast object, have you ever heard of vanta black?
http://newatlas.com/vantablack-s-vis-spray/42298/#gallery

 
Mathematics can not describe what happens at the center of a black hole, the singularity. At the singularity matter is not destroyed but time stands still. Once a black hole has consumed all the near by matter it will cease to grow and actually starts to shrink. This shrinking is due to Hawking Radiation. Given enough time (trillions of years) a black whole will evaporate.
 
the real answer is that nobody knows - there are lots of theories but no real evidence as their mere existence doesn't match our current theory of mavity.

you can pretty much ignore everything that anybody says about black holes as its most likely to be wrong.
 
aardvark said:
the real answer is that nobody knows - there are lots of theories but no real evidence as their mere existence doesn't match our current theory of mavity.

you can pretty much ignore everything that anybody says about black holes as its most likely to be wrong.
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Wrong there are things about black holes that we know.

Facts about Black Holes
  • The massive gravitational influence of a black hole distorts space and time in the near neighbourhood. The closer you get to a black hole, the slower time runs. Material that gets too close to a black hole gets sucked in and can never escape.
  • Material spirals in to a black hole through an accretion disk — a disk of gas, dust, stars and planets that fall into orbit the black hole.
  • The “point of no return” around a black hole is called the “event horizon”. This is the region where the mavity of the black hole overcomes the momentum of material spinning around it in the accretion disk. Once something cross the event horizon, it is lost to the pull of the black hole.
  • Black holes were first proposed to exist in the 18th century, but remained a mathematical curiosity until the first candidate black hole was found in 1964. It was called Cygnus X-1, an x-ray source in the constellation Cygnus.

http://space-facts.com/black-holes/
 
A black hole doesn't 'destroy' anything, it just scrambles the information beyond recognition.

Also the black hole does give off blackbody radiation - Hawking radiation, as mathematically proposed in order for them to be able to evaporate over time. (This is where the matter it has sucked up is slowly spewed out in scrambled form).
 
Tephnos said:
A black hole doesn't 'destroy' anything, it just scrambles the information beyond recognition.

Also the black hole does give off blackbody radiation - Hawking radiation, as mathematically proposed in order for them to be able to evaporate over time. (This is where the matter it has sucked up is slowly spewed out in scrambled form).
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Good way to think about it. It's like taking apart a lego set and havi no instructions to build it.

As far as I was aware. A black hole can get bigger. It's black because mavity bends light back into it.
It gets bigger when matter is added to it.
It isn't a hole
It's really just an incredibly dense dead star.

Neutron stars are a little less dense. You can see them because they aren't dense enough to bend light back in
 
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