Cosmic acceleration rediscovered

The following post was banned from sci.astro.research, sans notice (as
usual).
==========================

"Phillip Helbig---remove CLOTHES to reply"

wrote in message ...
In article , "Lars Wahlin"
writes:

A few years ago data from the Ia Supernova Cosmology Project found that
Hubble's law is not linear but changes in a nonlinear fashion at large
distances, i.e. The universe is accelerating.

This is just plain wrong. Hubble's Law says that recession velocity is
proportional to distance.

The "Hubble's law" to which you are referring is a theoretical construct.
Hubble's data connects distance with redshift -- not with recession
velocity.

This is actually quite trivial, since this is
the only relation which allows a homogeneous and isotropic universe to
remain so.

Your assumption has nothing to do with the discussion of the Hubble
relation. And it may have nothing to do with the real universe.

However, both the distance and velocity are not observable.

The distance is observable. The redshift is observable. The assumption
that velocity is the only contribution to redshift is pure theory (not
observable). Just like the last time this was discussed on this N.G.

http://www.google.com/groups?selm=10....supernews.com

Hubble's actual discovery was the linear apparent-magnitude--redshift
relation.

Carl Wirtz' discovery was the empirical redshift-distance relation in 1924
(pre Cepheid variable identification).

Hubble gave us the distance - redshift relation. He used Cepheid variable
stars to set the distance. And it is apparently linear for galaxies with
resolveable Cepheids. Again, just like it was discussed before in this N.G.
http://www.google.com/groups?selm=mt...tar.bris.ac.uk

FOR LOW REDSHIFT, one can use the former as a measure of
distance and the latter as a measure of velocity. However, this
relation is almost always observed whatever the cosmological parameters,
and is just a consequence of the fact that "things are linear to first
order".

In other words, "Hubble's Law" is by definition linear.

Argument-by-definition is not valid in the scientific method.

That you, and other theorists, like to assume that the distance-redshift
relationship is purely linear does not constrain the real universe. The
effect you are looking at may not be linear ... it may simply be the first
part of an exponential function.

What you mean is that a departure from this linearity is observed at
higher redshift, which indicates an expanding universe.

It only indicates an expanding universe if your assumption is true. Which
is not a given.

Well, this was actually
suggested long ago by Karachentsev .Commun. Buyrakan Obs. 39 96. (1967),
Ozernoy,Zh. Eksper. Teor. Fiz (Letters) 10, 394 (=JETP Letters 10 251),
(1969), de Vacouleurs, Publ. Astron. Pacific 83, 113 (1971) and
verified theoretically by myself (Wahlin, Astrophysics and space Science
74, 157 (1981)).

As Bill Press said in 1995, someone knows the value of the Hubble
constant to 1%---we just don't know who that person is.

Totally irrelevant.

I am not aware
of ANY observation-based arguments for an accelerating universe before
the 1990s which still stand up today. Sure, some people made some
observations and drew some conclusions. Maybe by chance the conclusions
were even correct. But it was just luck. Make a thousand predictions,
and one might be right.

Like your conclusion that the distance - redshift relation might be linear?
Unfortunately, this assumption will no longer 'stand up today.' The
supernovae data blew it away.

--
greywolf42
ubi dubium ibi libertas
{remove planet for e-mail}

[This may not thread correctly, my server rejected
a reply as the references line was too long.]

"Bjoern Feuerbacher" wrote in message
...

Then why did you never ask him why he keeps talking about
a "detected exponential curve"?

I have had many conversations with people putting
up unconventional theories. Usually I will point
out some flaw where observation rules out what they
propose and there will be some discussion of that
until they start to realise they are having
difficulty finding a flaw in my argument. Once that
happens, in my experience, they start trying to
change the subject. The smarter ones will often
drop in a throw-away line that looks innocuous but
if you pick up on it, they make it the main topic
and quietly snip any discussion of the data that
falsifies their theory.

His comment that the exponential is observed strikes
me as such an attempt to deflect the conversation so
I did not intend to take the bait.

Since you asked, I have brought up the point in my
latest post so maybe he will address it, but I really
want to stick to seeing whether he can identify any
cosmological model based on tired light that can
explain the frequency spectrum of the CMBR.

I really wonder if there are some severe reading comprehension
problems on his side, or if he does do that fully consciously,
for trolling...

I have found frequently with cranks and trolls that
they have so convinced themselves of their case that
they will read web pages, books and posts to mean
what they expect you to say without making much
attempt to actually understand the text. His reading
of the Ned Wright graph I cited is a case in point.
He assumed it was talking of a distant source and
therefore not relevant when, if he had looked and
considered carefully, he should have realised it was
talking of a local source.

Now that might be just carelessness or it might be
a deliberate ploy to try to discredit the argument,
but for the real cranks I know it is a self-imposed
blindness, they cannot allow such an idea to form
in their minds unless they already have a way to
rationalise it away. It is fscinating to take one
through all the steps needed to disprove their theory
without giving the game away and get them to agree
each step, then put them together at the end and show
how the combination rules out their idea. Suddenly
things that were obvious and agreed become
unacceptable as their minds rebel against the logic.

I don't think greywolf is that sort of person at all,
but it will be interesting to see what objections he
raises to my points.

best regards
George

George Dishman wrote:
[This may not thread correctly, my server rejected
a reply as the references line was too long.]

"Bjoern Feuerbacher" wrote in message
...

Then why did you never ask him why he keeps talking about
a "detected exponential curve"?


I have had many conversations with people putting
up unconventional theories. Usually I will point
out some flaw where observation rules out what they
propose and there will be some discussion of that
until they start to realise they are having
difficulty finding a flaw in my argument. Once that
happens, in my experience, they start trying to
change the subject. The smarter ones will often
drop in a throw-away line that looks innocuous but
if you pick up on it, they make it the main topic
and quietly snip any discussion of the data that
falsifies their theory.

His comment that the exponential is observed strikes
me as such an attempt to deflect the conversation so
I did not intend to take the bait.

Didn't he make that claim right from the start? So how
can it be an attempt to distract?


Since you asked, I have brought up the point in my
latest post so maybe he will address it, but I really
want to stick to seeing whether he can identify any
cosmological model based on tired light that can
explain the frequency spectrum of the CMBR.

It's really hard to get anything quantitative out of him...


I really wonder if there are some severe reading comprehension
problems on his side, or if he does do that fully consciously,
for trolling...


I have found frequently with cranks and trolls that
they have so convinced themselves of their case that
they will read web pages, books and posts to mean
what they expect you to say without making much
attempt to actually understand the text. His reading
of the Ned Wright graph I cited is a case in point.
He assumed it was talking of a distant source and
therefore not relevant when, if he had looked and
considered carefully, he should have realised it was
talking of a local source.

Now that might be just carelessness or it might be
a deliberate ploy to try to discredit the argument,
but for the real cranks I know it is a self-imposed
blindness, they cannot allow such an idea to form
in their minds unless they already have a way to
rationalise it away. It is fscinating to take one
through all the steps needed to disprove their theory
without giving the game away and get them to agree
each step, then put them together at the end and show
how the combination rules out their idea. Suddenly
things that were obvious and agreed become
unacceptable as their minds rebel against the logic.

Sounds like Morton's demon:
http://www.talkorigins.org/origins/postmonth/feb02.html
(be prepared that greywolf will now cry that I use ad hominems
by comparing him to creationists...)


[snip]


Bye,
Bjoern

"Bjoern Feuerbacher" wrote in message
...
George Dishman wrote:
[This may not thread correctly, my server rejected
a reply as the references line was too long.]

"Bjoern Feuerbacher" wrote in message
...

Then why did you never ask him why he keeps talking about
a "detected exponential curve"?


I have had many conversations with people putting
up unconventional theories. Usually I will point
out some flaw where observation rules out what they
propose and there will be some discussion of that
until they start to realise they are having
difficulty finding a flaw in my argument. Once that
happens, in my experience, they start trying to
change the subject. The smarter ones will often
drop in a throw-away line that looks innocuous but
if you pick up on it, they make it the main topic
and quietly snip any discussion of the data that
falsifies their theory.

His comment that the exponential is observed strikes
me as such an attempt to deflect the conversation so
I did not intend to take the bait.

Didn't he make that claim right from the start? So how
can it be an attempt to distract?

Actually you are right, he did, and mentioned it
again later after the thread had drifted. I really
haven't decided whether he is a troll or whether
it just appears that way because of his debating
style. The test for me is if he is willing to lay
aside those aspects and really look at the physics.

I have found frequently with cranks and trolls that
they have so convinced themselves of their case that
they will read web pages, books and posts to mean
what they expect you to say without making much
attempt to actually understand the text. ...

snip

Sounds like Morton's demon:
http://www.talkorigins.org/origins/postmonth/feb02.html

I haven't seen that before, it's perfect, exactly
the behaviour I was describing, thanks.

(be prepared that greywolf will now cry that I use ad hominems
by comparing him to creationists...)

I could understand he might, but was really thinking
of Gerald Kelleher and Aladar Stolmar and a few
others. I haven't decided about greywolf yet. He
might genuinely not have understood Wright's argument
so I give him the benefit of the doubt on principle
so far. Time will tell if he is willing to really
look at the physics instead of trying to win a
debating contest. You never know, he might just be
able to come up with a model that fits the data.

George

References lost due to ISP problem.

"greywolf42" wrote in message
...
George Dishman wrote in message
...

snip

Above you said that not all the red shift needed to
be due to tired light and suggested this was different
from BB.

Yes.

I agree that gravitational and proper motion
effects are present as well but that applies to BB too
so what did you mean above?

That the BB considers all redshift to be due to doppler due to
xpansion --
with miniscule corrections from peculiar motion dopplers and gravitational
shifts. The BB acknowledges that gravitational redshift, *real* motion
dopplers, and electron scattering do exist. But they are only minor
corrections on the whole.

Laying aside gravitational and other secondary effects
(S-Z etc.), the essential difference is that expansion
deals with the systematic motion while proper motion
is essentially that which departs from the overall trend.

Tired light theories presume the *additional* source of "tired light",
from
photon energy degradation.

Yep, got that.

But tired light theories therefore consider that
(non-expansion) doppler effects from "peculiar" or systematic motions will
not simply be small corrections to the cosmic expansion signature.

I still don't see the difference. To take a crude example,
the motions of individual galaxies in a cluster relative to
the centre of momentum would be proper motion while that of
the CoM itself would be mainly expansion but with an
equivalent proper motion relative to neighbouring clusters.
Is that not the same in both views?

Any systematic outward motion that would contribute to the
first order coefficient is simply expansion so you seem to
be suggesting that tired light could include an element of
expansion. Subtracting the tired light part would then give
you still a big bang model but with a much greater age.

To avoid a big bang scenario, you need to explain all the
systematic red shift with something other than motion and
at the moment I'll have to take that as photon energy loss
unless you can identify another contributor.

Tired
light theories agree with the BB that gravitational redshift and electron
scattering will be minor corrections on the whole.

Yes, I think those are common.

OK, that will let me illustrate how I think Ned's test
applies. I'll essentially throw a strawman at you and
you can then correct the errors in my understanding of
your model and we will see if that solves the problem.

Just doing the best you can with your view of Ned's site will be fine.
But
use a *real* tired light theory. (i.e. Vigiers.) I have no desire to
deal
with yet another strawman.

I'll ask you about your view. If that includes elements
of Vigiers then fine but if you want to make the case that
a tired light theory can satisfy the tests, it is for you
to make that case.

George

George Dishman wrote in message
...
References lost due to ISP problem.

"greywolf42" wrote in message
...
George Dishman wrote in message
...

snip

Above you said that not all the red shift needed to
be due to tired light and suggested this was different
from BB.

Yes.

I agree that gravitational and proper motion
effects are present as well but that applies to BB too
so what did you mean above?

That the BB considers all redshift to be due to doppler due to
expansion -- with miniscule corrections from peculiar
motion dopplers and gravitational shifts. The BB
acknowledges that gravitational redshift, *real* motion
dopplers, and electron scattering do exist. But they are only minor
corrections on the whole.

Laying aside gravitational and other secondary effects
(S-Z etc.), the essential difference is that expansion
deals with the systematic motion while proper motion
is essentially that which departs from the overall trend.

Closer. But many theories have systematic motions that are not due to
cosmic expansion. For example, the "plasma fireworks" model has systematic
doppler redshifts due to *true* motion. The BB theory incorporates an
additional assumption about physics and the expansion of *space* (or the
universe), that is not included in the plasma fireworks model.

Tired light theories presume the *additional* source of "tired light",
from photon energy degradation.

Yep, got that.

But tired light theories therefore consider that
(non-expansion) doppler effects from "peculiar" or systematic motions
will not simply be small corrections to the cosmic expansion signature.

I still don't see the difference. To take a crude example,
the motions of individual galaxies in a cluster relative to
the centre of momentum would be proper motion

The separation rate of the individual galaxies, relative to the CoM will
include a cosmic expansion coefficient in the BB.

while that of
the CoM itself would be mainly expansion but with an
equivalent proper motion relative to neighbouring clusters.
Is that not the same in both views?

No.

Any systematic outward motion that would contribute to the
first order coefficient is simply expansion

Not in the BB. There is spatial (universal) expansion and there is motion
through space expansion.

so you seem to
be suggesting that tired light could include an element of
expansion.

It could include an element of expansion by real motion through pre-existing
space.

Subtracting the tired light part would then give
you still a big bang model but with a much greater age.

It would not be a 'big bang' model. It would be a "real" explosion-type
model (i.e. "plasma fireworks"). And yes, the PF model has "ages of the
universe" of hundreds of billions to trillions of years. Though the meaning
of teh term "age of the univserse" is somewhat different between the two.

To avoid a big bang scenario, you need to explain all the
systematic red shift with something other than motion

But tired light models don't need a big bang scenario.

and
at the moment I'll have to take that as photon energy loss
unless you can identify another contributor.

Even plasma fireworks does not require the big bang. The latter adds
creation of space.

Tired
light theories agree with the BB that gravitational redshift and
electron scattering will be minor corrections on the whole.

Yes, I think those are common.

OK, that will let me illustrate how I think Ned's test
applies. I'll essentially throw a strawman at you and
you can then correct the errors in my understanding of
your model and we will see if that solves the problem.

Just doing the best you can with your view of Ned's site will be fine.
But use a *real* tired light theory. (i.e. Vigiers.) I have no desire
to deal with yet another strawman.

I'll ask you about your view. If that includes elements
of Vigiers then fine but if you want to make the case that
a tired light theory can satisfy the tests, it is for you
to make that case.

These are *your* "tests." It is up to you to support your claim about their
use. Feel free to use the tired light defining equation: dE = - mu E dx.
And feel free to use 1/mu = 4.2GPc (your R, from prior posts). I would
expect that you will perform a calculation to reproduce something similar to
Ned's curves (which are unsupported on Ned's site -- and trivially
incorrect).

Please let me know if this is insufficiently defined for your test.

--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}

"greywolf42" wrote in message
...
George Dishman wrote in message
...
most snipped

It would not be a 'big bang' model. It would be a "real" explosion-type
model (i.e. "plasma fireworks"). And yes, the PF model has "ages of the
universe" of hundreds of billions to trillions of years. Though the
meaning
of teh term "age of the univserse" is somewhat different between the two.

OK, this is more about terminology again, I would consider
that a variant of a big-bang model. If the theory includes
tired light to explain red shift then I would look on it
as a hybrid of the two. There's nothing wrong with that.
Regardless, it doesn't affect what we are trying to do.

To avoid a big bang scenario, you need to explain all the
systematic red shift with something other than motion

But tired light models don't need a big bang scenario.

and
at the moment I'll have to take that as photon energy loss
unless you can identify another contributor.

Even plasma fireworks does not require the big bang. The latter adds
creation of space.

Big bang describes the idea that at large scales, distances
between objects are systematically increasing. It doesn't
yet go back to creation since the theories break down at
least at the Planck time.

I'll ask you about your view. If that includes elements
of Vigiers then fine but if you want to make the case that
a tired light theory can satisfy the tests, it is for you
to make that case.

These are *your* "tests." It is up to you to support your claim about
their
use. Feel free to use the tired light defining equation: dE = - mu E dx.
And feel free to use 1/mu = 4.2GPc (your R, from prior posts). I would
expect that you will perform a calculation to reproduce something similar
to
Ned's curves (which are unsupported on Ned's site -- and trivially
incorrect).

Please let me know if this is insufficiently defined for your test.

That's fine. I have posted the example using exactly
those postulates. The id is



It may show up as a new thread though I used the same
subject line. Outlook Express is producing reference
lines in excess of 1000 characters, which is the
maximum according to the NNTP protocol, and my new
ISP's server is rejecting them. I had to post a new
message instead of a reply to get round it, sorry.

George

George Dishman wrote:
"greywolf42" wrote in message
...


[snip]


Even plasma fireworks does not require the big bang. The latter adds
creation of space.


Big bang describes the idea that at large scales, distances
between objects are systematically increasing. It doesn't
yet go back to creation since the theories break down at
least at the Planck time.

I think he did not mean the initial creation of space here,
but wanted to say that the expansion of the universe required
a continuous "creation" of "new" space.


[snip]

Bye,
Bjoern

Bjoern Feuerbacher wrote in message
...
George Dishman wrote:
"greywolf42" wrote in message
...


[snip]


Even plasma fireworks does not require the big bang. The latter adds
creation of space.


Big bang describes the idea that at large scales, distances
between objects are systematically increasing. It doesn't
yet go back to creation since the theories break down at
least at the Planck time.

I think he did not mean the initial creation of space here,
but wanted to say that the expansion of the universe required
a continuous "creation" of "new" space.

[snip]

I think we are all on the same page on this one. (Thank goodness.)

--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}

"Bjoern Feuerbacher" wrote in message
...
George Dishman wrote:
"greywolf42" wrote in message
...


[snip]


Even plasma fireworks does not require the big bang. The latter adds
creation of space.


Big bang describes the idea that at large scales, distances
between objects are systematically increasing. It doesn't
yet go back to creation since the theories break down at
least at the Planck time.

I think he did not mean the initial creation of space here,
but wanted to say that the expansion of the universe required
a continuous "creation" of "new" space.

Possibly, but I don't think it makes much sense to
describe expansion this way. In the big bang version,
photons can be thought of as being "stretched" during
their journey by the same factor as space expands but
"creation of new space" raises the prospect of a photon
getting cut in half if it happened to straddle the
location where a bit of "new space" was "created".

Both pictures, cutting a piece of vacuum in two and
putting more new vacuum inbetween or taking a piece
of vacuum and stretching it sound equally odd. Just
saying that material objects end up farther apart is
true either way.

I suspect red shift can be considered in terms of the
relationship between worldlines and geodesics at the
emitter and receiver again without worrying about
what happens in flight (but I can't be sure of that as
I haven't studied GR) but it makes more sense to me
than thinking of photons as extended objects that get
stretched along with the underlying "fabric of space".

George