Re: Do you believe in black holes?
- From: George Dishman <george@xxxxxxxxxxxxxxxxx>
- Date: Mon, 01 Oct 2007 08:40:12 -0700
On 30 Sep, 21:10, "N:dlzc D:aol T:com \(dlzc\)" <dl...@xxxxxxx> wrote:
"George Dishman" <geo...@xxxxxxxxxxxxxxxxx> wrote in message
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"dlzc" <dl...@xxxxxxx> wrote in message
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On Sep 26, 8:37 am, George Dishman <geo...@xxxxxxxxxxxxxxxxx>
wrote:
On 26 Sep, 14:34, "N:dlzcD:aol T:com \(dlzc\)"
<dl...@xxxxxxx> wrote:
"George Dishman" <geo...@xxxxxxxxxxxxxxxxx> wrote in
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On 25 Sep, 18:14,dlzc<dl...@xxxxxxx> wrote:
... we are going pretty far afield ...
I think some of this, particulary what is meant by
"information", is fundamental to our understanding
of the paper.
...
Unless I am mistaken, the photons in thermal
radiation carry no information.
"Black body radiation" is information.
Not in the QM sense AFAIK, the emission is random
and does not carry information about the source.
Heat transfer is to a body at its temperature. A real
body is or is not black, as far as absorption/emission.
Is temperature "information"?
No, in this context "information" is the quantum
numbers of the particles that entered the black
hole to provide it with its mass.
And how is it any different if the mass is located in the "Coal
Sack", speaking from QM? QM does not care about "spacetime
geometry", so I don't see how being "within an event horizon" is
any different.
I am losing why you think that is relevant to what
we are discussing. You said "'Black body radiation'
is information." but it does not contain information
in the QM sense regardless of the source of the
radiation.
Whether the stuff from which it is emitted is
ordered or not makes no difference to the
radiation, thus thermal radiation from a
black but highly ordered crystal is
indistiguishable from thermal radiation from
any other source.
You will have a characteristic emission when a
particular bond is formed. Note that diamond only
emits at a handful of wavelengths, so would be
quite distinguishable.
No, thermal black body radiation is described by
Planck's Law and is independent of the material.
Sorry, no.
http://links.jstor.org/sici?sici=0080-4630(19361202)157%3A892%3C579%3...
http://www.freepatentsonline.com/5883388.html
Diamond also only emits light near its bond energies.
Yes, the paper describes the spectra spcific to the
material which is nothing to do with black body
radiation:
http://en.wikipedia.org/wiki/Black_body
Read it again carefully. Diamond *can only initiate photons near
its bond energies*. Its emission is a far cry from anything
approaching a classical black body curve.
Yes, and since we are discussing Hawking radiation
which _is_ black body, I pointed out that your
reference to diamond which is _not_ black body is
not IMHO relevant. Why do you want to bring diamond
into the conversation?
Hawking radiation is black body and AIUI that
means it is generated randomly and doesn't
carry any information in the quantum sense.
It is not worth discussing further, since "temperature" =/=
"information", at least as far as keeping a mass from forming
into a BH.
The standard "information loss problem" AIUI is that
mass falls into the hole carrying with it information.
The hole evaporates giving off only Hawking Radiation
which has a purely thermal spectrum thus carries _no_
information and hence the information is lost. That
is the background to the discussion.
....
GR starts with spacetime issuing
from mass/energy, and inertia being a property
of the Universe and expressed at each bit of
mass, but loses any sense of that in its
derivation. You apparently take that as meaning
that such has been disproven. What it really
means is that GR is entirely transparent to that
question.
GR says the metric is distorted by stress/energy,
not that it "issues from" it, but your are right
about inertia.
How are "the field" and "the Universe" different, in
your opinion George? Einstein said "the field"
was responsible for curvature.
I would have to see the context to see which "field"
he meant, I don't know the quote. It may be just a
question of terminology, I might be using "metric"
or perhaps the means the "field equations".
"Relativity. The Special and the General Theory", Albert
Einstein, translation by John Lawson, copyright 1961. Appendix
Five "Relativity and the Problem of Space", the subsection "The
Concept of Space in the General Theory of Relativity", last
paragraph.
<QUOTE>
Thus Descartes was not so far from the truth when he believe he
must exclude the existence of an empty space. The notion indeed
appears absurd, as long a physical reality is seen exclusively in
ponderable bodies. It requires the idea of the field as the
representative of reality, in combination with the general
principle of relativity, to show the true kernel of Descartes'
idea; there exists no space "empty of field".
<END QUOTE... any typos are mine>
Same appendix, subsection "The Field", 4th paragraph
<QUOTE>
... In accordance with the historical development of the field
concept, where no matter was available there could exist no
field. But in the first quarter of the nineteenth it was shown
the that phenomena of the interference and motion of light could
be explained with astonishing clearness when light was regarded
as a wave-field, completely analogous to the mechanical vibration
field in an elastic solid body. It was thus felt necessary to
intoduce a field, that could also exist in "empty space" in the
absence of ponderable matter.
<END QUOTE... any typos are mine>
... further in this subsection, he mentions "modifiers" to (or
flavors of) the field theory... Maxwell, aether.
Based on the balance of the text, I think the field equations are
descriptors of "the field". But it is clear to me, "the field"
is fundamentally bonded to the "ponderable matter" necessary to,
for example, produce diffraction.
Thanks for the detail. I read it in the opposite sense,
it says:
"It was thus felt necessary to intoduce a field, that
could also exist in "empty space" in the absence of
ponderable matter."
However, the references are primarily to the electric
and magnetic fields of Maxwell's equations. You asked
me "How are 'the field' and 'the Universe' different,
in your opinion George?". If I put my hand in front of
a CRT, the hairs on the back of my hand stand up due
to the electric field. The universe is everything to
the limits of observability and beyond.
You also said "Einstein said 'the field' was responsible
for curvature.". The equations say the stress/energy
tensor causes curvature but the electric field is one
possible source of energy.
And we will continue to disagree. And it cannot be
experimentally disproven, since there is no stretch
of space that does not have two bits of matter /
energy either propagating through it, or "staring" at
each other across it. Only in "models" is such
"pure" spacetime availaable.
The GR model is quite clear on the matter though,
ripples can progress through the metric without
the need for matter other than the source:
There you go again... "without the need". Maybe
English is just too imprecise.
I think it is quite precise, a single accelerating
mass can generate gravitational waves, a single test
mass at some distance will respond to those and there
is no _need_ for any other masses in between to
propagate the wave.
Is there a Universe that contains those two masses-of-interest?
Thre is space, and IMHO "universe" is a term denoting
all of space and its contents of all forms.
Just because we do not include them in our analyses, "the field"
contributions from every bit of matter in the Universe are still
present.
The electric field is an attribute of space, it is
not generated by mass. It can have it's value altered
by charge which we usually associate with mass since
the only massless particles, photons, carry no charge.
Too bad I don't know another! ;>P QM does it
all without any spacetime / metric / curvature...
whatever it does.
Yes, it is couched in flat space but QED merges
QM with the weak field approximation of GR, in
other words it is asymptotically accurate for
small but non-zero curvatures.
http://lisa.nasa.gov/WHATIS/grav-wave.html
If LISA detects the waves then the model is as
well proven as you get in science, the ISM is
particles at a very low density so there is a
lot of empty space between them that those waves
must have crossed.
The volume is not empty. The volume only contains
little if any matter.
The waves would propagate equally well if it
contained no matter whatsoever.
The volume is still framed by a Universe, which has a field that
"supports" or "underlies" this volume. Otherwise, we could not
establish a size.
I see no connection between the existence of a field
and the ability to measure distance.
Redshift and intensity agree when spanning
this volume too.
It still serves the thermodynamic purpose of providing
"available states" between all the bits of matter
around (not necessarily near) it. As well as conveying
light.
But gravitational waves are not light, nor are
they thermodynamic in nature.
It remains to be seen whether gravitational waves are not light.
Certainly a whole bunch of people would be flabbergasted if it
were, myself included.
But conservation of angular momentum, and the associated transfer
of energy are indeed thermodynamic. Hell, they even associate
thermodynamics with computer information!
...
... is devoid of mention of the matter/energy that
the curvature issued from. As if *your
interpretation* were the only one that survives. I
don't agree, and I apologize for bringing it up.
GR is a set of equations, "interpretation" doesn't
come into it IMHO. It should be possible to look at
the model of a BH and say where an external
influence at some time originated, near but outside
the horizon or inside. My point is that the result of
that is only valid within GR, and GR only gives one
answer.
It give two different answers, apparently.One in
terms of its "founding principles", and (at least)
one in terms of the formalisms adopted to
produce quantifiable predictions.
First I heard of that, what are these "two different
answers" and what was the question? AFAIK
only the equations make any predictions.
Two different answers:
1) matter does it,
2) curvature does it.
Does what? Matter causes curvature, curvature
causes .... gravity?
Davd, I'll have to break off there. I'll try
to reply to the rest later.
George
.
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