Black Holes violate the Heisenberg Uncertainty Principle.

On 8/18/17 9:30 PM, Jeff-Relf.Me@. wrote:
Tom Roberts wrote: Jeff-Relf wrote:
There's ZERO evidence that a true black hole exists;
Not true. There is considerable evidence that supermassive black holes lie
near the center of most galaxies.

A very dense objects, yes. TRUE black holes, no. Black Holes violate the
Heisenberg Uncertainty Principle.

That theoretical prejudice does not invalidate the observational evidence that
black holes exist. For Sgr A* to not be a black hole requires violating other
theoretical prejudices of comparable stature.

Moreover, I believe that the violation of the HUP occurs deep inside the
horizon, not outside where the observational evidence is. Nobody expects the GR
model to remain valid deep inside the horizon, because we expect quantum effects
to become significant there, and we don't know how to reconcile GR with QM.

And you completely ignored the other evidence:
In addition, the gravitational waves observed by LIGO are not consistent with
any known hypothesis other than that they were generated by collisions
between black holes.

Tom Roberts

On 8/21/17 6:46 PM, Jeff-Relf.Me@. wrote:
You ( Tom Roberts ) replied ( to me ):
the gravitational waves observed by LIGO are not consistent with
any known hypothesis other than that they were generated by
collisions between black holes.

They could've been similar to black holes, but not quite;

No. They merged in a ways consistent with black holes in GR, and inconsistent
with any known type of material objects.

A very dense objects, yes. TRUE black holes, no.
Black Holes violate the Heisenberg Uncertainty Principle.

That theoretical prejudice does not invalidate
the observational evidence that black holes exist.

There is no evidence that TRUE black holes exist, none.

Yes, there is. Your "none" is WRONG. YOU may not be convinced by it, but a
majority of the astrophysics community is.

For Sgr A* to not be a black hole requires violating other
theoretical prejudices of comparable stature.

Like what ? It could be a "SemiClassical Black Star".

No, because we don't see the radiation that would come from the infalling matter
hitting the surface of such an object.

Nobody expects the GR model to remain valid deep inside the horizon,
because we expect quantum effects to become significant there,
and we don't know how to reconcile GR with QM.

Exactly, we don't know.

There are things we do know, and things we don't know. We DO know that there are
objects in the universe which are MUCH better described as black holes than as
any other type of object.

HERE'S MY KEY POINT:
Until some better model is developed, scientists will model them as black holes.
You seem to be seeking some sort of "complete and absolutely true knowledge" --
that simply is not possible for humans in the world we inhabit.

more data, from more observers, is needed.

Always true, and this is no different from essentially any other field.

Tom Roberts

Jeff-Relf.Me @. writes:

We can't see Sgr A* PROPER, directly, and you need
INFINITE precision to measure a TRUE singularity.

Doesn't matter, it's the size of the event horizon that counts, not
the singularity. As long as there is enough mass inside an event horizon
there is a black hole, even if there is weird physics unknown to us
inside that prevents formation of a singularity. We can never know what
happens inside an event horizon.

We see that Sgr A* is there, not by seeing it, but by tracking stars
that are orbiting it.

https://en.wikipedia.org/wiki/S0%E2%80%93102
https://en.wikipedia.org/wiki/S2_(star)
amongst others

On 8/23/17 4:26 PM, Michael Moroney wrote:
Jeff-Relf.Me @. writes:

We can't see Sgr A* PROPER, directly, and you need
INFINITE precision to measure a TRUE singularity.

Doesn't matter, it's the size of the event horizon that counts, not
the singularity. As long as there is enough mass inside an event horizon
there is a black hole, even if there is weird physics unknown to us
inside that prevents formation of a singularity. We can never know what
happens inside an event horizon.

We see that Sgr A* is there, not by seeing it, but by tracking stars
that are orbiting it.

https://en.wikipedia.org/wiki/S0%E2%80%93102
https://en.wikipedia.org/wiki/S2_(star)
amongst others


And to emphasize this, the "true" black hole is NOT the singularity. The
defining feature is the event horizon.

There's no point in demanding proof in terms of something unobservable.

--
Odd Bodkin -- maker of fine toys, tools, tables

Jeff-Relf.Me @. writes:

Sagittarius A* is THOUGHT to be the location of a supermassive black hole
https://en.wikipedia.org/wiki/Sagittarius_A*

"Thought", not "known".

"Thought" to a rather high degree of certainty.

Orbits of multiple stars are tracked orbiting "something"
with a mass of about 4.1 million solar masses but a radius of less than 45 AU
(otherwise the star S14 would collide with it).

https://upload.wikimedia.org/wikiped...tre_orbits.svg

On 24/08/2017 00:01, Michael Moroney wrote:
Jeff-Relf.Me @. writes:

Sagittarius A* is THOUGHT to be the location of a supermassive black hole
https://en.wikipedia.org/wiki/Sagittarius_A*

"Thought", not "known".

"Thought" to a rather high degree of certainty.

Orbits of multiple stars are tracked orbiting "something"
with a mass of about 4.1 million solar masses but a radius of less than 45 AU
(otherwise the star S14 would collide with it).

https://upload.wikimedia.org/wikiped...tre_orbits.svg

Wiki claims Sgr A has Rs ~ 1.3x10^10 M which I make to be about 80AU
(in the section on Schwarzchild radii - which is suspect is out of date)

(although the page on Sgr A itself says 4.1M sun and about 45AU)

Star S14 must be getting awfully close to grazing the event horizon.

Is it possible to see and interpret gravitational and Doppler spectral
shifts for it as well as positional measurements?

Presumably we have to wait patiently for something chunky to go down the
gravitational plughole and then we will get to find out the period of
the last stable orbit more precisely.

--
Regards,
Martin Brown

Martin Brown wrote:

On 24/08/2017 00:01, Michael Moroney wrote:
Jeff-Relf.Me @. writes:
Sagittarius A* is THOUGHT to be the location of a supermassive black
hole
https://en.wikipedia.org/wiki/Sagittarius_A*

"Thought", not "known".

"Thought" to a rather high degree of certainty.

Orbits of multiple stars are tracked orbiting "something"
with a mass of about 4.1 million solar masses but a radius of less than
45 AU (otherwise the star S14 would collide with it).


https://upload.wikimedia.org/wikiped...tre_orbits.svg

Wiki

The name is of the source is _Wikipedia_. Instead, “wiki� is now an
umbrella term for a live-editable community-maintained online source
(from “wiki�, the Hawaiian word for “quick�).

claims Sgr A

The name of the astronomical object is obviously S(a)g(itta)r(ius) A_*_
(emphasis mine).

has Rs ~ 1.3x10^10 M which I make to be about 80AU

What are you talking about?

The symbol for radius is usually a lowercase “r�.

The symbol for the SI unit of metre (or meter) is “m�, not “M�. [“M� is
reserved as the unit prefix for “megaâ€�, from greek «μÎ*γας» /megas/ „great“,
meaning one million times the unit.]

The SI unit prefix “kâ€� (for “kiloâ€�, from Greek «χίλιοι» /khÃ*lioi/ „a
thousand“) means 1000 times the unit:

1 km = 1000 m.

So

1.3 × 10¹� m = 1.3 × 10� km

which is *much less* than

1 AU ≈ 150'000'000 km = 150 × 10� km = 1.5 × 10¹� km.

(1 AU is the average distance Terra–Sol.)

(in the section on Schwarzchild radii

(Karl) _Schwarzschild_

- which is suspect is out of date)

It is not. The Schwarzschild radius of a non-rotating, uncharged
(Schwarzschild) black hole (BH) is

rₛ = 2 G M∕c²,

where G is Newton’s gravitational constant, and M is the mass of the black
hole. A mass of

M = 4.1 × 10� M☉ ≈ 8.153 × 10³� kg,

where the mass of Sol (or solar masses) is

M☉ ≈ 1.988435 × 10³� kg,

corresponds to a Schwarzschild radius of

rₛ ≈ 1.211 × 10¹� m = 1.211 × 10� km ≈ 0.08094 AU

The is very close to the aforementioned 1.3 × 10¹� m.

See also:
http://www.wolframalpha.com/input/?i=Schwarzschild+radius&dataset=

(although the page on Sgr A itself says 4.1M sun and about 45AU)

You are confusing the radius of the region surrounding the assumed black
hole with the Schwarzschild radius of the black hole, whereas the former is
much larger. Note that for such a BH, the Schwarzschild radius is the
radius beyond which we can have *no* information instead (as it *is* the
radius of the *event horizon*).

Star S14 must be getting awfully close to grazing the event horizon.

That is possible, but not based on your argument, but based on the diagram.

For a Schwarzschild BH, the outer event horizon is the surface of a sphere
that has the Schwarzschild radius as its radius. 45 AU, the radius of the
space in which S14 is described to be orbiting, is not anywhere near
0.08 AU.

--
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

Thomas 'PointedEars' Lahn writes:

Martin Brown wrote:

(although the page on Sgr A itself says 4.1M sun and about 45AU)

You are confusing the radius of the region surrounding the assumed black
hole with the Schwarzschild radius of the black hole, whereas the former is
much larger. Note that for such a BH, the Schwarzschild radius is the
radius beyond which we can have *no* information instead (as it *is* the
radius of the *event horizon*).

The "45AU" size is the maximum radius of whatever "it" is, if it was any
larger, Star S14 would collide with it. So "it" must be smaller than 45
AU radius.

Since we know of no physics that allows for an object of 45 AU radius and a
mass of 4.1M sun, other than a black hole or something rapidly collapsing
into a black hole, this is excellent evidence of a black hole there.

Star S14 must be getting awfully close to grazing the event horizon.

That is possible, but not based on your argument, but based on the diagram.

For a Schwarzschild BH, the outer event horizon is the surface of a sphere
that has the Schwarzschild radius as its radius. 45 AU, the radius of the
space in which S14 is described to be orbiting, is not anywhere near
0.08 AU.

About 560 times the event horizon radius. However it is close enough to
likely have interesting relativistic effects. Another star (S0-102) gets
within 260 AU and reaches over 1% of the speed of light. S14 must be
really booking.

[Since I have temporarily disengaged my killfile anyway …]

Michael Moroney amok-crossposted to 3 newsgroups, *despite* F’up2 being
already set:

Thomas 'PointedEars' Lahn writes:
Martin Brown wrote:
(although the page on Sgr A itself says 4.1M sun and about 45AU)
You are confusing the radius of the region surrounding the assumed black
hole with the Schwarzschild radius of the black hole, whereas the former
is much larger. Note that for such a BH, the Schwarzschild radius is the
radius beyond which we can have *no* information instead (as it *is* the
radius of the *event horizon*).

The "45AU" size is the maximum radius of whatever "it" is, if it was any
larger, Star S14 would collide with it.

No, if the "central" body’s radius would be _that size or larger_, the
"orbiting" S14 would collide with it, assuming that the description that S14
comes as close to that body’s *center of mass* as 45 AU is correct.

So "it" must be smaller than 45 AU radius.

That much is true. And I have just *calculated* how small or large "it"
*really* must be if it is a black hole, given this mass: about 0.08 AU,
which is *much* smaller than 45 AU. (Can you not read?)

Since we know of no physics that allows for an object of 45 AU radius
and a mass of 4.1M sun, other than a black hole or something rapidly
collapsing into a black hole, this is excellent evidence of a black hole
there.

Not even wrong. Rather, *any* object can have a radius of *45 AU* and a
total mass of about 4.1 million solar masses. (Homework assignment: Look up
statistics of celestial objects to find at least one such object.)

And an object that has either a mass of 4.1 million solar masses *and* a
radius of about 0.08 AU or less, or a radius of 45 AU and a mass of

rₛ = 2 G M∕c²

M = c² rₛ∕(2 G)

M(r = 45 AU) ≈ 4.533 × 10³� kg ≈ 2.28 × 10� M☉ [thanks, Wolfram|Alpha]

(2.28 *billion* solar masses, short scale) or *more*, must be a black hole.

For a Schwarzschild BH, the outer event horizon is the surface of a
sphere that has the Schwarzschild radius as its radius. 45 AU, the
radius of the space in which S14 is described to be orbiting, is not
anywhere near 0.08 AU.

About 560 times the event horizon radius.

You don’t say!

However it is close enough to likely have interesting relativistic
effects.

You probably mean “cause�, not “have�.

Another star (S0-102) gets within 260 AU and reaches over 1% of
the speed of light.

The *special*-relativistic effects (and *those* are concerned when it comes
to relative speeds) at 0.01 c (≈ 30'000 km∕s; according to Wolfram|Alpha,
the typical CRT electron speed) are *negligibly small*:

γ(0.01 c) ≈ 1∕√(1 − 0.01²) ≈ 1.00005 ∎

As a rule of thumb, as far as relative speeds are concerned, things get
interesting at and over about 0.42 c (42 % c), where γ makes a difference
in lengths and times of 10 % or more of the rest frame values.

S14 must be really booking.

I do not know that idiom, but I presume it refers to high (orbital) speed
(as in bets on horse racing). If so, you would probably be correct _in the
≤ 45 AU vicinity of Sgr A*_.

However, sadly, you have no clue what you are talking about.


F’up2 news:sci.astro

--
PointedEars

Twitter: @PointedEars2
Please do not cc me. / Bitte keine Kopien per E-Mail.

Thomas 'PointedEars' Lahn writes:

Michael Moroney amok-crossposted to 3 newsgroups, *despite* F’up2 being
already set:

So why did you crosspost to 3 newsgroups, if you feel it's so wrong?

The "45AU" size is the maximum radius of whatever "it" is, if it was any
larger, Star S14 would collide with it.

No, if the "central" body’s radius would be _that size or larger_, the
"orbiting" S14 would collide with it, assuming that the description that S14
comes as close to that body’s *center of mass* as 45 AU is correct.

Which is what I said.

So "it" must be smaller than 45 AU radius.

That much is true. And I have just *calculated* how small or large "it"
*really* must be if it is a black hole, given this mass: about 0.08 AU,
which is *much* smaller than 45 AU. (Can you not read?)

Yes. Can you?

Since we know of no physics that allows for an object of 45 AU radius
and a mass of 4.1M sun, other than a black hole or something rapidly
collapsing into a black hole, this is excellent evidence of a black hole
there.

Not even wrong. Rather, *any* object can have a radius of *45 AU* and a
total mass of about 4.1 million solar masses. (Homework assignment: Look up
statistics of celestial objects to find at least one such object.)

Wrong. If it had both characteristics, no known physics allows such a thing
to exist, except temporarily as it collapses into a black hole.

OK, a black hole plus a bunch of stuff orbiting it (out to a radius of 45 AU)
could exist, but since my point was this was excellent evidence of a black
hole, this is foolish quibbling.

However, sadly, you have no clue what you are talking about.

As if you did.