Re: Time dilation and expanding space

Dear Robert Karl Stonjek:

"Robert Karl Stonjek" <stonjek@xxxxxxxxxxxxxx> wrote in message
news:pjqHh.8145$8U4.4892@xxxxxxxxxxxxxxxxxxxxxxxxxxxxx
GR Specifically models the effect that gravity has on
the motion of objects as they pass through a
gravitational field - the curvature of spacetime. That
is where GR is in its element. But if we just want to
know about how a Black Hole is different from, say,
a planet then there are several ways of modelling that.

No discipline can model the evolution of a black hole
from a star than quantum mechanics. Special
relativity plays a secondary role and general relativity
a tertiary role in the QM description of the evolution
of Black Holes.

Since there is no gravitation, time, or space in QM...
I'd be fascinated in how you think QM describes any
such "evolution".

As a star collapses it goes through a phase where it
becomes a neutron star - well described in QM. Further
collapse is also a quantum phenomena.

Actually no. There is no quantum state (short of the magic
singularity) that can withstand additional pressure, which is
then no longer quantum.

You seem to forget that stars are made of matter
that collapses under its own weight when the nuclear
fires go out.

Or when the mass is too high. I don't think a supermassive BH
needs to go through a "slow death" stage.

The evolution of a star to black hole starts with the
star and it's nuclear reactions - well described by QM.

QM says nothing about the "forces" that degrade a normal star
into a BH over time. So I would agree to an equal partnership
between GR and QM, if you'd be willing to compromise?

Each of these explanations fail to take into account
that as we approach the speed of light the distance
the photon travels falls to zero and the interval of
transit also falls to zero - photons can not be held
in suspended animation.

One can drop an object from very near the EH
starting essentially at rest, on a very large black
hole, and the infalling object will not be
"approaching the speed of light" for some long
time later. I think you invoke an image that will
not serve you well later.

Photons are not objects and they do not accelerate.

By "approaching the speed of light" was referring to
the math ie at 0.5c, 0.75c, 0.9c, 0.99c, that is, as
we approach the speed of light. As there is no light
frame, conditions at c can only be inferred by
conditions at c-1/infinity ie very slightly slower than
c, which is a valid inertial frame.

For instance in the frame of a neutrino emitted at
a speed of almost c just after the big bang and
absorbed by a detector here on earth interval of
emission to absorption will be a few seconds and
the distance that the neutrino travelled will be just
a few millimetres.

That is all fine and good. However, I can emit a particle with
near zero speed near the event horizon, and it will be travelling
nowhere near c when it crosses the EH. Only for objects "falling
from infinity", or directed towards the EH with significant speed
is the phrase "approaching the speed of light" correct.

Remember, you said *as we approach the speed of light*, and
talked about what we see.

Additionally, light has been held to very near zero
speed, such that a material object outside the BE
condensate envelope can outpace it.
And I understand you meant "in vacuuo". But...

Light travelling through a medium is absorbed and
re-radiated numerous times. The speed of light
may thus seem to be less but it is in fact no
slower at all. Between particles *is* a vacuum,
regardless of the density of the material, and through
that vacuum light travels at c.

You are confusing the transmission of a light beam
through a medium with the speed of a photon through
space, which is always c and NEVER slower. It
does not matter if that space is the vacuum between
galaxies or the vacuum between sub-atomic particles.

Then what did you mean by:

Each of these explanations fail to take into account
that as we approach the speed of light the distance
the photon travels falls to zero and the interval of
transit also falls to zero - photons can not be held
in suspended animation.

We have held photons in suspended animation (BE condensate). We
have trapped photons in quantum wells (we can even "measure" them
there without absorbing them). You seem to be saying that we
will measure c to decrease, if we are infallers. What did you
mean to say?

Light does not randomly lose a little energy in passing.
That is how we recognize ancient objects... because
their spectra are unaltered (absorption notwithstanding).
Light very much is in suspended animation, when you
consider it never loses energy, and were you to be able
to travel alongside it, would appear as a stationary E
and M field... a 'standing wave' as it were.

You can not travel alongside a photon, even in principle.
The reason is that the universe is far too small. For the
interval at c as a photon travels from one side of the
universe to the other is zero and the distance that the
photon travels at c is zero ie the point of emission and
absorption are touching in the c frame.

c has no frame. You cannot apply / infer the LT and say
something about what a photon sees, however much poetry you see
there. The derivation of the LT *forbids* v = c. And it is
clear that photons respond to that which they pass, so they are
"aware" of the space they are passing through.

In essence, the speed of a photon in the light
frame is zero, because it travels no distance in no
time.

No.

You are confusing the basics of photonic radiation
and Special relativity with Newtonian physics,
where one could happily travel alongside a photon
*in principle*.

You are the one applying formulae where they cannot be applied...

Here are some SR basics - the speed of light is
always c regardless of the frame of the observer
(assuming the beam of light is travelling through a
vacuum or the speed of single photons is being
observed). Thus if you managed to get yourself to
c-1/infinity speed and shone a torch, the light
would leave that torch at the speed of light *relative
to you and your torch*.

Thank you. Consider that a photon clustered near a "maxima of an
EM wave" will always be in that position. The wave is static to
the photon.

The flat space model says that clocks near to the
singularity are so dilated that they never tick, so to
speak, so an emitting source never emits a photon.
This flat space model is the only one that is
consistent with the known conditions close to the
speed of light.

Since such a clock cannot be at rest, this "image"
is useless.

You're confused. If time is sufficiently dilated then
no observer outside the frame of that clock will
observe the clock ever ticking eg if the clock were
travelling at the speed of light it would never tick
even if it travelled from one side of the universe to
the other in 20 billion of our Earth years.

You are positioning the clock near the singularity. Nothing you
have said applies to the condition stated.

It may well tick in its own frame, but just what
that means is beyond our purchase as there is
no way that we can witness that ticking,
even in principle.

Obviously GR is a specialist tool that is the most
accurate tool when applied to its specialisation (it
explains the way that matter curve space and the
way that objects move in curve space). But there
are other specialist tools that do far better than
GR in their own areas of specialisation. Even so,
each tool can explain the other, even if only in
principle (or very tentatively, such as the 'graviton'
account of gravity proper by QM), even if badly,
not particularly accurately, or in a convoluted
manner.

Thus I await the alternative explanations of
expanding space. What is the QM model?

There is no spacetime in QM. A thing has happened
or it hasn't. Where the participants are located is
inconsequential. And there is no entropy... a proton
a billion years old and one that just formed in pair
creation have thh same identical quantum properties.

Photons are quantums of light are regularly modeled
in spacetime.

From Wikipedia:
<snip non sequitur>

Special Relativity, including spacetime, have always been
part quantum mechainics.

Only when mapping QM to the world we live in. In other words QM
is the engine, and SR / GR are the transmission and wheels. They
work and play in entirely separate realms, and they have to be
spliced together.

Only large scale general relativity is not currently
modeled in QM

No. No part of spacetime is modelled in QM.

How would you curve space in the lab given
unlimited resources?

Magnets do this all the time. Curve it a lot, or
curve it a very little, and amplify it by lots of
"charges". The curvature we already have is
usually just too small to measure.

Magnets do not curve space, they 'polarise' it.
If a magnet curved space then all objects would
be effected by that curved space and not just a
few magnetic metals such as iron.

It is only "polarized" to charges. And its isn't "polarized" if
the charge is co-moving with the "current". Sounds like a very
tiny curvature.

The standard around here really drops when you
stop quoting from text book learning and try to
think for yourself.

http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_60/iss_3/16_1.shtml
Since you start spouting more non-sequitur, here is curvature
here on Earth.

Space is expanding between the Milky way and
Andromeda.

Probable (IMO), but expansion has not yet been
observed within our supercluster. There is a single
observation that might "allow" expansion between
the Earth and the Moon... but that is with many
years of very precise data. Data not yet available
between the Milky Way and Andromeda.

There is still discussion and debate on whether all
spacetime expands or just the spacetime between
structures (such as superclusters.) Of course
spacetime is curved between Earth and the moon,
both objects curve spacetime and the pair of objects
also curve spacetime (eg a distant object feels a
greater pull from the Earth-moon combination than
just from the Earth alone).

Hubble expansion has purportedly been identified between the
Earth and the Moon in the LLR data. The paper is on arxiv, in
2003 or so if I recall.

As the net motion of Andromeda is toward rather
than away from the Milky Way I postulate that
light speed expansion is not involved.

Some commentators say that all space expands,
others that only the space between major
structures expands (which was my original
understanding). I've given up any hope of finding
a convincing argument one way or the other.
Even so, light speed expansion between objects
is not necessary in all cases.

What specifically do you mean by "light speed
expansion"?

Where two objects are moving away from each
other at or greater than the speed of light as
measured from either object (there is normally a
speed of light speed limit, but expanding
spacetime exceeds this limit).


What is the two dimensional (granny's incontinence
rubber *** version) model of expanding space?

It depends on gravity to deform the ***. That is
one of the problem with analogies.

Your 'small early' universe emitting light to a 'bigger
later' universe has a gravity component - the gravitational
potential at the emitter will be greater than the
gravitational potential of the absorber because of the
greater radius of the absorber and so the lower density.
But that would also mean that time dilation was a reality
at the absorber and not a product of expanding space
time ie one year in the emitter's frame is greater than
one year in the absorber's frame.

Maybe "not only the product of expanding spacetime" would be more
correct? Expansion would still be present, or you would not have
the change in density / potential between ages.

Earlier in this thread the claim was made that no
actual time dilation took place as the light was merely
stretched between the emitter and absorber ie between
high redshift objects and, say, Hubble.

Yes, and I hated this description when I first had it used on me.
We *cannot* modify photons this way in the lab, so photons are
not "stretched". It is only a (IMO) very poor metal model.

Space *must* expand. Consider that perhaps there
is only time, and the laws of physics. Early
mathematicians in studying the interactions of
billiard balls noted that two body interactions define
two orthogonal axes, and three (or more) bodies
generate 3D space. Space is simply the *result* of
time and conservation of momentum. Since space
is not some rigid structure, but is dependent, its
expansion can be generated by diddling with clocks.
The laws of physics will maintain a local "normality".

And particles get bigger?

Smaller. Balanced against "conservation of charge" and
"conservation of energy".

No, space does not expand - there is nothing to
expand.

Anyway, there is no space without time.

Let's have a reference for your expanding space fantasy.

In time. ;>)

Indeed. And neither is any single thing 'moving' faster
than light due to expanding space. The two are often
differentiated by considering SR type motion as
'inertial' motion. Note that if an object is moving away
from you faster than the speed of light then it is
invisible.

But it could be moving parallel to you, and you could
still receive light from faces that were parallel to it
line-of-flight.

No.

Yes. No matter how fast an object was moving in "X", I could
still bounce light off of it in "Y" or "Z", from faces that were
primarily oriented in "Y" or "Z".

Spatial expansion is in every direction.

Just like altering a clock... making every *now* shrink from the
one before.

David A. Smith


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