About black holes

[israel socratus]

Book: ''' Stephen Hawking. A life in science ''
''Together with Brandon Carter and Jim Bardeen, Hawking wrote a paper,
published in Communications in Mathematical Physics , pointing out . . .
the team commented, '' In fact the effective temperature of a black hole
is absolute zero . . . . No radiation could be emitted from the hole.''
/ page 156./
But later (!) , . . using concepts of entropy and Heisenberg uncertainty
principle and quantum fluctuations (!) Hawking changed his mind
and wrote that black holes can radiate.
/ Book: ''' Stephen Hawking. A life in science '' by Michael White and John Gribbin/
#
So, in the beginning ( according to calculations) the ''black hole''
had absolute zero temperature (like the Cosmic Vacuum: T=0K) . . .
but . . . thanks to entropy, Heisenberg uncertainty principle and
quantum fluctuations the absolute zero temperature was changed.
Conclusion:
Cosmic Vacuum and black holes are one and the same system.
Black holes are parts of the infinite Cosmic Vacuum.

[israel socratus]

At the core of the Milky Way galaxy, contains a supermassive black hole
of about 4.3 million solar masses.
Supermassive black holes with a mass between 0.1 million and 10 billion M☉.
Some astronomers have begun labeling black holes of at least 10 billion M☉
as ultramassive black holes.
Even larger ones have been dubbed stupendously large black holes (SLABs)
with masses greater than 100 billion M☉.
Some studies have suggested that the maximum mass that a black hole can reach,
while being luminous accretors, is of the order of ~50 billion M☉.
https://en.wikipedia.org/wiki/Supermassive_black_hole

[israel socratus]

1- A black hole has a temperature within a few millionths
of a degree above absolute zero
/ Oxford. Dictionary./
2- A stellar black hole of one solar mass has a Hawking temperature
of about 100 nanokelvins. This is far less than the 2.7 K temperature
of the cosmic microwave background Black hole
/Wikipedia/
3- A black hole of one solar mass (M☉) has a temperature
of only 60 nanokelvin (60 billionths of a kelvin)
/ Wikipedia /

[jillery]

On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
<socrat...@gmail.com> wrote:

>1- A black hole has a temperature within a few millionths
>of a degree above absolute zero
>/ Oxford. Dictionary./
>2- A stellar black hole of one solar mass has a Hawking temperature
> of about 100 nanokelvins. This is far less than the 2.7 K temperature
> of the cosmic microwave background Black hole
>/Wikipedia/

>3- A black hole of one solar mass (M?) has a temperature

>of only 60 nanokelvin (60 billionths of a kelvin)
>/ Wikipedia /

Question: How can a black hole be colder than the space which
surrounds it?

--
You're entitled to your own opinions.
You're not entitled to your own facts.

[Glenn]

On Sunday, September 25, 2022 at 11:45:22 PM UTC-7, jillery wrote:
> On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
> <socrat...@gmail.com> wrote:
>
> >1- A black hole has a temperature within a few millionths
> >of a degree above absolute zero
> >/ Oxford. Dictionary./
> >2- A stellar black hole of one solar mass has a Hawking temperature
> > of about 100 nanokelvins. This is far less than the 2.7 K temperature
> > of the cosmic microwave background Black hole
> >/Wikipedia/
> >3- A black hole of one solar mass (M?) has a temperature
> >of only 60 nanokelvin (60 billionths of a kelvin)
> >/ Wikipedia /
> Question: How can a black hole be colder than the space which
> surrounds it?
>

Yea, how come my fridge is colder inside than outside?

[jillery]

On Sun, 25 Sep 2022 23:52:01 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

Yea, God created Black Hole compressors and insulators.

[J. J. Lodder]

jillery <69jp...@gmail.com> wrote:

> On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
> <socrat...@gmail.com> wrote:
>
> >1- A black hole has a temperature within a few millionths
> >of a degree above absolute zero
> >/ Oxford. Dictionary./
> >2- A stellar black hole of one solar mass has a Hawking temperature
> > of about 100 nanokelvins. This is far less than the 2.7 K temperature
> > of the cosmic microwave background Black hole
> >/Wikipedia/
> >3- A black hole of one solar mass (M?) has a temperature
> >of only 60 nanokelvin (60 billionths of a kelvin)
> >/ Wikipedia /
>
>
> Question: How can a black hole be colder than the space which
> surrounds it?

Gravity provides negentropy,

Jan

[Glenn]

What are Black Hole compressors and insulators?

[Glenn]

Just the facts, eh? Who could argue with that?

"The thermodynamic description of gravity has a history that goes back at least to research on black hole thermodynamics by Bekenstein and Hawking in the mid-1970s. These studies suggest a deep connection between gravity and thermodynamics, which describes the behavior of heat. In 1995, Jacobson demonstrated that the Einstein field equations describing relativistic gravitation can be derived by combining general thermodynamic considerations with the equivalence principle.[1] Subsequently, other physicists, most notably Thanu Padmanabhan, began to explore links between gravity and entropy.[2][3]"

https://en.wikipedia.org/wiki/Entropic_gravity

[erik simpson]

Well, if you'd actually read a little bit further, you'd see that lots of people have argued with that. Well, not
people, physicists.

[Glenn]

You're a genus.

[erik simpson]

Thanks, but I demurr. I just paid attention and learned some stuff.

[Glenn]

As above, so below.

[Bob Casanova]

On Mon, 26 Sep 2022 14:20:33 -0700 (PDT), the following
appeared in talk.origins, posted by erik simpson
<eastsi...@gmail.com>:

Check his spelling; I doubt it was accidental.
>
--

Bob C.

"The most exciting phrase to hear in science,
the one that heralds new discoveries, is not
'Eureka!' but 'That's funny...'"

- Isaac Asimov

[Dale]

On 9/23/2022 1:07 AM, israel socratus wrote:
> ... wrote that black holes can radiate ...

Black can be an additive color or a subtractive color?

https://en.wikipedia.org/wiki/Additive_color

https://en.wikipedia.org/wiki/Subtractive_color

https://en.wikipedia.org/wiki/Black_body

https://en.wikipedia.org/wiki/Black-body_radiation

--
Mystery? -> https://www.dalekelly.org/

[jillery]

I suppose that's one way to become a genus, but other genera might
claim you didn't evolve correctly.

[jillery]

On Mon, 26 Sep 2022 10:48:48 -0700 (PDT), Glenn <GlennS...@msn.com>

That's what makes Black Hole fridges, of course. Isn't that what you
meant?

[Glenn]

How would I know what you meant?

[J. J. Lodder]

Well, its Glenn. He goes by buzzword,
not by understanding what it is about,

Jan

[Ernest Major]

On 26/09/2022 07:41, jillery wrote:
> On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
> <socrat...@gmail.com> wrote:
>
>> 1- A black hole has a temperature within a few millionths
>> of a degree above absolute zero
>> / Oxford. Dictionary./
>> 2- A stellar black hole of one solar mass has a Hawking temperature
>> of about 100 nanokelvins. This is far less than the 2.7 K temperature
>> of the cosmic microwave background Black hole
>> /Wikipedia/
>> 3- A black hole of one solar mass (M?) has a temperature
>> of only 60 nanokelvin (60 billionths of a kelvin)
>> / Wikipedia /
>
>
> Question: How can a black hole be colder than the space which
> surrounds it?
>

At a phenomenological level when a black hole absorbs heat from its
surroundings its mass increases, and therefore so does its event
horizon. The surface area increases faster than the total Hawking
radiation flux, so the effect is to cool the black hole's surface.

--
alias Ernest Major

[jillery]

Now that's a coherent and understandable answer. Thank you, Major.

[Glenn]

An event horizon is a "surface"?

"Black holes are freezing cold on the inside, but incredibly hot just outside. The internal temperature of a black hole with the mass of our Sun is around one-millionth of a degree above absolute zero. Just outside the hole, however, the material being pulled into the hole’s gravity well is accelerated to near the speed of light. The molecules of the material collide with such vigour that it is heated up to a temperature of hundreds of millions of degrees."

https://kids.tpl.ca/wonders/71

[Glenn]

Or perhaps it's just spin, like black holes, at near light speed.

[J. J. Lodder]

Ernest Major <{$to$}@meden.demon.co.uk> wrote:

Yes, but in 10^100 years or so the relation will have been reversed,
and the black holes wil start heating up the universe,
until they are gone.

See John Baez's FAQ for details,

Jan
(getting real cold at the thought)

[Bob Casanova]

On Tue, 27 Sep 2022 10:14:03 -0700 (PDT), the following
appeared in talk.origins, posted by Glenn
<GlennS...@msn.com>:

>On Tuesday, September 27, 2022 at 4:50:23 AM UTC-7, Ernest Major wrote:
>> On 26/09/2022 07:41, jillery wrote:
>> > On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
>> > <socrat...@gmail.com> wrote:
>> >
>> >> 1- A black hole has a temperature within a few millionths
>> >> of a degree above absolute zero
>> >> / Oxford. Dictionary./
>> >> 2- A stellar black hole of one solar mass has a Hawking temperature
>> >> of about 100 nanokelvins. This is far less than the 2.7 K temperature
>> >> of the cosmic microwave background Black hole
>> >> /Wikipedia/
>> >> 3- A black hole of one solar mass (M?) has a temperature
>> >> of only 60 nanokelvin (60 billionths of a kelvin)
>> >> / Wikipedia /
>> >
>> >
>> > Question: How can a black hole be colder than the space which
>> > surrounds it?
>> >
>> At a phenomenological level when a black hole absorbs heat from its
>> surroundings its mass increases, and therefore so does its event
>> horizon. The surface area increases faster than the total Hawking
>> radiation flux, so the effect is to cool the black hole's surface.
>>
>An event horizon is a "surface"?
>

Yes.

>
>"Black holes are freezing cold on the inside, but incredibly hot just outside. The internal temperature of a black hole with the mass of our Sun is around one-millionth of a degree above absolute zero. Just outside the hole, however, the material being pulled into the hole’s gravity well is accelerated to near the speed of light. The molecules of the material collide with such vigour that it is heated up to a temperature of hundreds of millions of degrees."
>
>https://kids.tpl.ca/wonders/71

[Bob Casanova]

On Tue, 27 Sep 2022 21:01:14 +0200, the following appeared
in talk.origins, posted by nos...@de-ster.demon.nl (J. J.
Lodder):

I suspect that we, and all our descendant species, will be
dead by then.

>
>See John Baez's FAQ for details,
>
>Jan
>(getting real cold at the thought)
>
>

[jillery]

On Tue, 27 Sep 2022 10:14:03 -0700 (PDT), Glenn <GlennS...@msn.com>
wrote:

>On Tuesday, September 27, 2022 at 4:50:23 AM UTC-7, Ernest Major wrote:
>> On 26/09/2022 07:41, jillery wrote:
>> > On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
>> > <socrat...@gmail.com> wrote:
>> >
>> >> 1- A black hole has a temperature within a few millionths
>> >> of a degree above absolute zero
>> >> / Oxford. Dictionary./
>> >> 2- A stellar black hole of one solar mass has a Hawking temperature
>> >> of about 100 nanokelvins. This is far less than the 2.7 K temperature
>> >> of the cosmic microwave background Black hole
>> >> /Wikipedia/
>> >> 3- A black hole of one solar mass (M?) has a temperature
>> >> of only 60 nanokelvin (60 billionths of a kelvin)
>> >> / Wikipedia /
>> >
>> >
>> > Question: How can a black hole be colder than the space which
>> > surrounds it?
>> >
>> At a phenomenological level when a black hole absorbs heat from its
>> surroundings its mass increases, and therefore so does its event
>> horizon. The surface area increases faster than the total Hawking
>> radiation flux, so the effect is to cool the black hole's surface.
>>
>An event horizon is a "surface"?

An event horizon is the boundary beyond which nothing can escape. For
sufficiently large black holes, an observer could cross its event
horizon without any ill effects. So it's just a region of spacetime,
not a physical surface.

Some define a black hole's surface as the event horizon, but there
remains whatever is inside a black hole, about which nobody knows.

One speculation is that all the mass and energy of a black hole is
compressed in a singularity, an infinitely dense point of spacetime.
OTOH QM rules exclude singularities. OTGH QM rules might not apply
beyond an event horizon.

>"Black holes are freezing cold on the inside, but incredibly hot just outside. The internal temperature of a black hole with the mass of our Sun is around one-millionth of a degree above absolute zero. Just outside the hole, however, the material being pulled into the hole’s gravity well is accelerated to near the speed of light. The molecules of the material collide with such vigour that it is heated up to a temperature of hundreds of millions of degrees."
>
>https://kids.tpl.ca/wonders/71

[Glenn]

You must be a genus. Only the shadow knows.

[Ernest Major]

The resident topologist might be disappointed in him.

--
alias Ernest Major

[J. J. Lodder]

Little hope, when all the stars have burned out...

Jan

[Bob Casanova]

On Wed, 28 Sep 2022 11:06:12 -0700 (PDT), the following

Thanks, but no; I'm not even all of a single species.
>
> Only the shadow knows.
>> >
He does indeed. That's why he ignores you.

[erik simpson]

I think or resident topologist studies different kinds of topology than differential, but I wouldn't
bet on it.

[Bob Casanova]

On Wed, 28 Sep 2022 19:52:43 +0100, the following appeared
in talk.origins, posted by Ernest Major
<{$to$}@meden.demon.co.uk>:

Or not; it might just be further confirmation of existing
knowledge.

[Bob Casanova]

On Wed, 28 Sep 2022 21:51:10 +0200, the following appeared

Yep.

[Glenn]

I don't mind that you distract from your silly answer to a silly question, to sarcasm of a non-trivial question of the subject of black holes.

Is the interior of a black hole very cold because the surface area increases faster than the total Hawking radiation flux? And even were you referring to the "surface" only, why is that why is that an explanation?

"In astrophysics, an event horizon is a boundary"

"A misconception concerning event horizons, especially black hole event horizons, is that they represent an immutable surface that destroys objects that approach them."

https://en.wikipedia.org/wiki/Event_horizon

"A surface, as the term is most generally used, is the outermost or uppermost layer of a physical object or space"
"In mathematics, a surface is a mathematical model of the common concept of a surface."
https://en.wikipedia.org/wiki/Surface

"In topology and mathematics in general, the boundary of a subset S of a topological space X is the set of points in the closure of S not belonging to the interior of S."
https://en.wikipedia.org/wiki/Boundary_(topology)

As I understand black holes, they do not have a "layer" of space, nor an "immutable surface. It occurs to me that your representation could provide for an incorrect understanding of black "holes" as currently exists.

[Glenn]

And you know so much more about differential topology that you would bet on it.

[John Bode]

On 9/27/22 12:14 PM, Glenn wrote:
> On Tuesday, September 27, 2022 at 4:50:23 AM UTC-7, Ernest Major wrote:
>> On 26/09/2022 07:41, jillery wrote:
>>> On Sun, 25 Sep 2022 17:57:22 -0700 (PDT), israel socratus
>>> <socrat...@gmail.com> wrote:
>>>
>>>> 1- A black hole has a temperature within a few millionths
>>>> of a degree above absolute zero
>>>> / Oxford. Dictionary./
>>>> 2- A stellar black hole of one solar mass has a Hawking temperature
>>>> of about 100 nanokelvins. This is far less than the 2.7 K temperature
>>>> of the cosmic microwave background Black hole
>>>> /Wikipedia/
>>>> 3- A black hole of one solar mass (M?) has a temperature
>>>> of only 60 nanokelvin (60 billionths of a kelvin)
>>>> / Wikipedia /
>>>
>>>
>>> Question: How can a black hole be colder than the space which
>>> surrounds it?
>>>
>> At a phenomenological level when a black hole absorbs heat from its
>> surroundings its mass increases, and therefore so does its event
>> horizon. The surface area increases faster than the total Hawking
>> radiation flux, so the effect is to cool the black hole's surface.
>>
> An event horizon is a "surface"?

For this purpose, yes.

It's not a tangible, solid thing you can touch or stand on, no. But it
is a well-defined boundary between the "inside" and "outside" of the
black hole.

Inside the event horizon, spacetime is so warped that all worldlines
converge on the singularity - no matter what direction you travel, the
singularity will always be straight ahead of you.

And like Ernest said, if the event horizon expands faster than the
Hawking radiation flux, then the "surface" cools.