| Topic: |
Science > Physics |
| User: |
"Herbert Haas" |
| Date: |
09 May 2005 01:40:36 AM |
| Object: |
black hole entropy |
Dear experts,
what is the entropy of a black hole?
I found the formula S=A*k*c³/(4*h*G) but I could not find how to get to
this.
Thanks!
Best regards
Herbert
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| User: "Old Man" |
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| Title: Re: black hole entropy |
09 May 2005 08:22:17 AM |
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"Herbert Haas" <hh@localhost.localdomain> wrote in message
news:pan.2005.05.09.06.40.35.904583@localhost.localdomain...
Dear experts,
what is the entropy of a black hole?
I found the formula S=A*k*c³/(4*h*G) but I could not find how to get to
this.
Thanks!
Best regards
Herbert
The essential physics here is that the entropy of a black hole
is directly proportional to the surface area, A, of its event
horizon.
[Old Man]
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| User: "G=EMC^2 Glazier" |
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| Title: Re: black hole entropy |
09 May 2005 03:57:58 PM |
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Old Man A BH has a temperature so it has to have entropy. Little tricky
thinking about BH with a temperature and not radiating it outward.
When Bekenstien came up with black holes having entropy Hawking went
bull *****. About two years later he tried to claim that idea as his
thinking.You are right going with the event horizon area. Any theory
that goes under the surface of a black hole is sci-fiction. I don't
know what the temp.of a black hole is,but it must be colder than the
2.7K of space. Bert
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| User: "Sam Wormley" |
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| Title: Re: black hole entropy |
09 May 2005 06:12:17 PM |
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G=EMC^2 Glazier wrote:
Old Man A BH has a temperature so it has to have entropy. Little tricky
thinking about BH with a temperature and not radiating it outward.
When Bekenstien came up with black holes having entropy Hawking went
bull *****. About two years later he tried to claim that idea as his
thinking.You are right going with the event horizon area. Any theory
that goes under the surface of a black hole is sci-fiction. I don't
know what the temp.of a black hole is,but it must be colder than the
2.7K of space. Bert
As Old Man just pointed out Herb--The essential physics here is that
the entropy of a black hole is directly proportional to the surface
area, A, of its event horizon.
Plug the area into the equation at
http://scienceworld.wolfram.com/physics/BlackHole.html
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| User: "Traveler" |
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| Title: Re: black hole entropy |
09 May 2005 06:28:47 PM |
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In article <l7Sfe.70539$WI3.52289@attbi_s71>, Sam Wormley
<swormley1@mchsi.com> wrote:
G=EMC^2 Glazier wrote:
Old Man A BH has a temperature so it has to have entropy. Little tricky
thinking about BH with a temperature and not radiating it outward.
When Bekenstien came up with black holes having entropy Hawking went
bull *****. About two years later he tried to claim that idea as his
thinking.You are right going with the event horizon area. Any theory
that goes under the surface of a black hole is sci-fiction. I don't
know what the temp.of a black hole is,but it must be colder than the
2.7K of space. Bert
As Old Man just pointed out Herb--The essential physics here is that
the entropy of a black hole is directly proportional to the surface
area, A, of its event horizon.
It's always funny watching a bunch of stupid religious morons discuss
one of their favorite religious icons. Black holes, wormholes, time
travel via closed timelike curves, parallel universes, etc...
Chicken-***** Star-Trek physics, all of it.
Louis Savain
The Silver Bullet: Why Software Is Bad and What We Can Do to Fix it
http://users.adelphia.net/~lilavois/Cosas/Reliability.htm
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| User: "The Ghost In The Machine" |
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| Title: Re: black hole entropy |
10 May 2005 01:00:16 AM |
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In sci.physics, Traveler
<traveler@nospam.net>
wrote
on Mon, 09 May 2005 19:28:47 -0400
<b8sv7150rvgi07itiop72bqkt3ml05tsi3@4ax.com>:
In article <l7Sfe.70539$WI3.52289@attbi_s71>, Sam Wormley
<swormley1@mchsi.com> wrote:
G=EMC^2 Glazier wrote:
Old Man A BH has a temperature so it has to have entropy. Little tricky
thinking about BH with a temperature and not radiating it outward.
When Bekenstien came up with black holes having entropy Hawking went
bull *****. About two years later he tried to claim that idea as his
thinking.You are right going with the event horizon area. Any theory
that goes under the surface of a black hole is sci-fiction. I don't
know what the temp.of a black hole is,but it must be colder than the
2.7K of space. Bert
As Old Man just pointed out Herb--The essential physics here is that
the entropy of a black hole is directly proportional to the surface
area, A, of its event horizon.
It's always funny watching a bunch of stupid religious morons discuss
one of their favorite religious icons. Black holes, wormholes, time
travel via closed timelike curves, parallel universes, etc...
Chicken-***** Star-Trek physics, all of it.
There's some evidence black holes exist; look at Cygnus X-1, for
instance, a strong X-ray source. (The X-rays are caused by
gas being pressurized as it swirls down the drain. At least,
that's the standard explanation. Alternative ones are acceptable
IF they explain the observations better than a black hole.)
As for wormholes, I for one would consider them far less likely;
the amount of energy to create one would be extremely large.
SR does not postulate anything regarding parallel universes.
[.sigsnip]
--
#191,
It's still legal to go .sigless.
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| User: "G=EMC^2 Glazier" |
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| Title: Re: black hole entropy |
10 May 2005 01:40:17 PM |
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Traveler Anyone that thinks black holes do not exist has his head
buried deep in the sand. We have quasars that are objects billions of
times more massive than our sun in an area the size of our solar
system,and they can only be powered by a BH. The core of Cygnus x-1 has
a black hole in its core much like our galaxy,and Andromeda with a mass
of 30 million Suns. Stupid conservative minds will never cotton to BH
Einstien spoke of such people when he gave the world his SR,and GR
theories. He called them "weak thinkers" Bert
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| User: "Raymond Yohros" |
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| Title: Re: black hole entropy |
10 May 2005 06:14:47 PM |
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G=EMC^2 Glazier wrote:
Traveler Anyone that thinks black holes do not exist has his head
buried deep in the sand. We have quasars that are objects billions
of
times more massive than our sun in an area the size of our solar
system,and they can only be powered by a BH. The core of Cygnus x-1
has
a black hole in its core much like our galaxy,and Andromeda with a
mass
of 30 million Suns. Stupid conservative minds will never cotton to BH
Einstien spoke of such people when he gave the world his SR,and GR
theories. He called them "weak thinkers" Bert
Black holes can be the explanation of every single
object in the universe. they hold the destiny of matenergy
and define the waveform of spacetime.
www.sonofsound.com
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| User: "Dave P." |
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| Title: Re: black hole entropy |
11 May 2005 09:30:40 AM |
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On Mon, 09 May 2005 23:12:17 GMT, Sam Wormley <swormley1@mchsi.com>
wrote:
G=EMC^2 Glazier wrote:
Old Man A BH has a temperature so it has to have entropy. Little tricky
thinking about BH with a temperature and not radiating it outward.
When Bekenstien came up with black holes having entropy Hawking went
bull *****. About two years later he tried to claim that idea as his
thinking.You are right going with the event horizon area. Any theory
that goes under the surface of a black hole is sci-fiction. I don't
know what the temp.of a black hole is,but it must be colder than the
2.7K of space. Bert
As Old Man just pointed out Herb--The essential physics here is that
the entropy of a black hole is directly proportional to the surface
area, A, of its event horizon.
And, because Black holes show only two characteristics to the world,
charge and spin, and because no rearrangement of the internal
constituents of a black hole (whatever they may be) will have any
effect on those two characteristics, a black hole of a particular size
(represented by the event horizon) represents the maximal amount of
entropy that can be supported by any region of space equivalent in
size to that black hole's event horizon.
Dave P.
Plug the area into the equation at
http://scienceworld.wolfram.com/physics/BlackHole.html
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| User: "G=EMC^2 Glazier" |
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| Title: Re: black hole entropy |
11 May 2005 05:14:55 PM |
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Dave P More than two characteristics. You left our "mass" Myself I can
live with black holes not having entropy. Like I posted they are not
radiating heat out. I know entropy fits with all other objects in the
universe,but a black hole could be an exception. Could it fit with my
"black hole critical mass theory" It would go like this Black holes hid
their entropy until they reach their critical mass,and release it all at
the time it explodes creating a mini-bang and hence a new universe. You
can't get any greater disorder than a mini-bang. Well I guess I just
don't like a black hole as being warm. I will have fast rotating black
holes as warm,and non-rotating as cold. Even the warm ones will never
have their temp. measured. Bert
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| User: "Sam Wormley" |
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| Title: Re: black hole entropy |
09 May 2005 01:46:13 AM |
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Herbert Haas wrote:
Dear experts,
what is the entropy of a black hole?
I found the formula S=A*k*c³/(4*h*G) but I could not find how to get to
this.
Thanks!
Best regards
Herbert
Note: http://scienceworld.wolfram.com/physics/Entropy.html
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| User: "Herbert Haas" |
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| Title: Re: black hole entropy |
11 May 2005 02:57:55 PM |
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Many thanks to all of you for your contributions!
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