Cosmic acceleration rediscovered

George Dishman wrote in message
...

I'm going to reply in full to this but it's already
much too long. Can I suggest either you do some severe
snipping or I will on my next reply.

OK, I'll cut out all the discussions re the definitions of the Hubble Term.
We reached closure there, I think....

I'll also cut the I said/ no I saids......

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

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


{snip}

Well the most obvious is the intensity of the CMBR:

http://www.astro.ucla.edu/~wright/tiredlit.gif

The energy degradation variant of Tired light

Which one? *ALL* tired light theories have energy degradation!
(Even if Ned Wright's strawmen don't fit into this category.)

I think it was clear I meant those where individual
photons lose energy but are not destroyed.

{snip}

would reduce the energy of each photon but not the flux.

That is the assumption of the BB.

Nonsense, it is simply a consequence of the fact that
the number of particles is conserved.

It is assuming that the number of particles is conserved, *while* the
big bang expansion is going on.

No, the proof applies if the number is conserved even in
a steady state universe.

Not in Ned's example. But let's look at your version.

Suppose we were at the centre of
a hot steel sphere of constant size, billions of light
years in diameter (silly, I know but it illustrates the
point), the energy of individual photons would be reduced
in transit by Tired Light but the rate of photons arriving
would not. The result would not match what was measured by
FIRAS.

There is no reason that they should. Because you are again assuming that
the CMBR is the result of a cosmic, universal and simultaneous event (or
events). This is a Big Bang assumption. It could be shoehorned into a
steady-state theory, but it is not a requirement of steady-state theory or
tired light theory. Eddington first calcuated that temperature by using
simple starlight.

For example, in my favorite theory (a Maxwellian/LeSage theory), the CMBR is
simply an EM hum from electrons bound to hydrogen.

snip

(It is true of Vigier's QM version, I believe. But not of
Maxwell's, Olber's, or LeSages.)

There may be others as well. I don't pretend to know
of all the possibilities but the point is that those
in which the red-shift mechanism does not also reduce
the flux of photons need to find a way to "meet the
data" as you put it from FIRAS.

The data from FIRAS is not a confirmation that the universe expanded.

I didn't say it was, my point stands.

Your argument is based on the CMBR being BB afterglow. Or some other cosmic
event.

{snip}

Here's a link discussing both Ned Wright and MTW:

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

And another with more detail:

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

See my reply to Bjoern on those threads.

I did. Pretty pathetic wriggling, don't you think?

Either something
got damaged in the cut & paste (maybe MTW's ;-) or I misread
the quotes.

Nope. Those are direct quotes. No typos. And you didn't misread them.

If Zel'dovich said:
"We ask the question: if there were such a process,

and MTW supposedly copied it but it became:
"If there does not exist any such decay process,

something is wrong.

That part is the noted shortening of the argument done by MTW. Note the
lack of quotation marks on #3, by MTW.

Anyway, it's academic at present since I didn't use those arguments.

True.

snip
Anyway, as you can see, I gave you a different argument above.

Hey, I enjoy being proved wrong on that kind of prediction. Even if
your argument was just a repetition of a vague and hand-wavy effort

It gives a quantitative analysis for an example source
temperature.

But not one that is used in tired light theories.

The only thing hand-wavy is that he cannot
use a specific temperature without a specific Tired Light
model to test. The example illustrates the method.

But it is based entirely on the assumption of the CMBR being the BB
afterglow. Which is not part of tired light theories. (Because the BB
isn't.)

{snip}

in your own link, farther below. You wouldn't listen to Aladar's claims
that his theory was different. You insisted that *all* theories are the
same as Zwicky's.

Aladar's claim was that he was the first person ever to
suggest that Tired Light would produce an exponential
relationship between distance and frequency.

Uh, no. What Aladar claimed was that his was the first theory that included
causation. Zwicky's did not.

I also
pointed out that _his_ theory was falsified by the FIRAS
data. That isn't the same as claiming "*all* Tired Light
theories are the same as Zwicky's."

You claimed that his theory was the same as Zwicky's *because* they both had
exponential energy removal. Then you claimed that all such theories were
falsified by FIRAS.

Which is simply assuming your conclusion (the BB).

{snip}

And that is still the issue. The nonlinearity of the data. Versus
the linearity of the theory.

And again you try to create the strawman.

Strawman? It's the starting point of the original post in the thread in
this newsgroup! As documented, above.

Yes it was, and it was a strawman then too.

It is not a strawman. The SN1a data curve was not predicted by the hubble
law -- even the epoch-dependent version. (That is why we have "dark
energy.") It *was* predicted by tired light theories.

{snip}

so stop
handwaving and start discussing specifics. Otherwise
all I can do is give you general indications of the
tests that can be applied.

Well, one test was the prediction of the nonlinearity discovered in the
SN1a data. That big-bangers now classify as "dark energy."

Again you imply the strawman of expected linearity in the
SNe data.

"Dark energy" was not predicted by the big bang. Dark energy is an ad hoc
modification to the BB, to explain a deviation between the form of the
observed redshift-distance curve versus the theoretical redshift-distance
curve. The form of the observed redshift-distance curve was predicted by
tired light.

What is described as "dark energy" is the unknown
cause of the _deviation_ from the predicted _non-linearity_
which, in the conventional model,

Yes, we agree.

implies expansion is now accelerating.

Only if you refuse to consider the alternative.

The Hubble Law remains linear.

The question is, does the "Hubble law" reflect the real universe.

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

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

I'm going to reply in full to this but it's already
much too long. Can I suggest either you do some severe
snipping or I will on my next reply.

OK, I'll cut out all the discussions re the definitions of the Hubble
Term.
We reached closure there, I think....

I'll just note the bit at the bottom:

What is described as "dark energy" is the unknown
cause of the _deviation_ from the predicted _non-linearity_
which, in the conventional model,

Yes, we agree.

That wrapped it up for me, thanks.


I'll also cut the I said/ no I saids......

That's what I really meant. I'm not really interested in
that sort of argument though I can't allow a mis-statement
of my views to pass without correcting it once. I'm sure
you will pick me up if I mis-state your views too.


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

snip

No, the proof applies if the number is conserved even in
a steady state universe.

Not in Ned's example. But let's look at your version.

Suppose we were at the centre of
a hot steel sphere of constant size, billions of light
years in diameter (silly, I know but it illustrates the
point), the energy of individual photons would be reduced
in transit by Tired Light but the rate of photons arriving
would not. The result would not match what was measured by
FIRAS.

There is no reason that they should. Because you are again assuming that
the CMBR is the result of a cosmic, universal and simultaneous event (or
events).

No, but I am assuming that whatever the source, it is
essentially a blackbody spectrum, i.e. thermally generated


This is a Big Bang assumption. It could be shoehorned into a
steady-state theory, but it is not a requirement of steady-state theory or
tired light theory. Eddington first calcuated that temperature by using
simple starlight.

It meets my assumption though because he used starlight
to heat interstellar material which then re-radiated
thermally. The above argument then applies.

For example, in my favorite theory (a Maxwellian/LeSage theory), the CMBR
is
simply an EM hum from electrons bound to hydrogen.

But that doesn't produce the spectrum we see, hydrogen
radiates in discrete lines. How does it get to the
observd spectrum?

snip repeat of above


If Zel'dovich said:
"We ask the question: if there were such a process,

and MTW supposedly copied it but it became:
"If there does not exist any such decay process,

something is wrong.

That part is the noted shortening of the argument done by MTW. Note the
lack of quotation marks on #3, by MTW.

Perhaps but the condition seems to be inverted. Anyway,
I don't see any benefit in pursuing that at the moment

Anyway, it's academic at present since I didn't use those arguments.

True.

snip
Anyway, as you can see, I gave you a different argument above.

Hey, I enjoy being proved wrong on that kind of prediction. Even if
your argument was just a repetition of a vague and hand-wavy effort

It gives a quantitative analysis for an example source
temperature.

But not one that is used in tired light theories.

It is in some. This is partly why you get what you call
hand-waving answers. There are so many Tired Light
theories, no one analysis applies to all.

snip repetition of above arguments

in your own link, farther below. You wouldn't listen to Aladar's
claims
that his theory was different. You insisted that *all* theories are
the
same as Zwicky's.

Aladar's claim was that he was the first person ever to
suggest that Tired Light would produce an exponential
relationship between distance and frequency.

Uh, no. What Aladar claimed was that his was the first theory that
included
causation. Zwicky's did not.

I spent nearly two years discussing this with him. I won't
start digging out Google references but I can asure you it
took me a long time to convince him he wasn't the first.

I also
pointed out that _his_ theory was falsified by the FIRAS
data. That isn't the same as claiming "*all* Tired Light
theories are the same as Zwicky's."

You claimed that his theory was the same as Zwicky's

No, I never did that. Zwicky could not have known of the
the CMBR but Aladar claimed it was integrated red-shifted
galactic light in an infinite universe. He claimed nobody
had realised this because everyone else thought the energy
loss was linear (IIRC), not exponential.

snip
Strawman? It's the starting point of the original post in the thread
in
this newsgroup! As documented, above.

Yes it was, and it was a strawman then too.

It is not a strawman. The SN1a data curve was not predicted by the hubble
law -- even the epoch-dependent version. (That is why we have "dark
energy.") It *was* predicted by tired light theories.

I wonder if you mean the same as me. What you say is
true, but unrelated. A strawman is producing a false
version of a theory which can be shown to be false
when the real theory could not. I was talking of your
attempts to suggest the red-shift should be proportional
to distance even at high z in Big Bang theories.

{snip}

so stop
handwaving and start discussing specifics. Otherwise
all I can do is give you general indications of the
tests that can be applied.

Well, one test was the prediction of the nonlinearity discovered in the
SN1a data. That big-bangers now classify as "dark energy."

Again you imply the strawman of expected linearity in the
SNe data.

"Dark energy" was not predicted by the big bang. Dark energy is an ad hoc
modification to the BB, to explain a deviation between the form of the
observed redshift-distance curve versus the theoretical redshift-distance
curve.

Again I don't disagree but your strawman was to imply that
the theoretical redshift-distance in BB is linear.

The form of the observed redshift-distance curve was predicted by
tired light.

Now we are getting somewhere, this is what i would rather
discuss. Which tired light theory predicts this and what
is the formula for the curve?

What is described as "dark energy" is the unknown
cause of the _deviation_ from the predicted _non-linearity_
which, in the conventional model,

Yes, we agree.

implies expansion is now accelerating.

Only if you refuse to consider the alternative.

That was in reference to the expansion model only of course.

The Hubble Law remains linear.

The question is, does the "Hubble law" reflect the real universe.

No, the question is does the conventional model reflect
the real universe. There's lots more than just the Hubble
Law involved and many tests that it could yet fail.

George

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


[snip]

"Dark energy" was not predicted by the big bang. Dark energy is an ad hoc
modification to the BB, to explain a deviation between the form of the
observed redshift-distance curve versus the theoretical redshift-distance
curve.


Again I don't disagree but your strawman was to imply that
the theoretical redshift-distance in BB is linear.

Well, I disagree. True, dark energy was not predicted by the BBT
directly. But it is neither an ad hoc modification of it! The
cosmological constant is essentially a free parameter in the equations
of GR. In previous times, people set it to zero (because there were no
observations which showed differently, and there were some *very* hand
waving arguments that it probably is zero), but when the new
measurements of the SNs came in, we found out that this parameter in
reality is not zero. That's science: determining parameters of a
theory by observations.

I explained this several times to greywolf42, but he simply refuses to
understand my argument...

OTOH, some alternative models to explain the accelerated expansion, like
e.g. quintessence, I would perhaps call "ad hoc" - because there is
indication at all that such a scalar field exists. It was really only
introduced in order to save some problems in the theory.



The form of the observed redshift-distance curve was predicted by
tired light.


Now we are getting somewhere, this is what i would rather
discuss. Which tired light theory predicts this and what
is the formula for the curve?

And which tired light theory predicted the new data, which shows
(according to the standard GR explanation) that at earlier times, the
expansion was decelerating? (astro-ph/0402512)

Which of the tired light theories agree with all the other established
theories, i.e. GR and QFT, by the way?


[snip]

Bye,
Bjoern

Joseph Lazio wrote in message
...
"g" == greywolf42 writes:

g "Joseph Lazio" wrote in message
news ...
"g" == greywolf42 writes:

g Then why do you constantly ignore the possibility that the
g redshift-distance relation is an exponential curve?
Do the data support such a notion?

g Yes.

O.k. I suppose that I am not surprised by that answer.

g For a quick reference, see Perlmutter, Figure 3, Physics Today,
g April 2003, "Supernovae, Dark Energy, and the Accelerating
g Universe".
g http://www.slac.stanford.edu/econf/C...perlmutter.pdf

Figure 3? Is this the correct reference?

No. The reference is as given above. This was a download I made on 11/10.
But I can't seem to find the online source link, anymore. Sorry.

If you'd like, I can e-mail you the proper .pdf file.

g Just notice that instead of "accelerating universe" and
g "decelerating universe" (...), one should read: "exponential
g redshift-distance relation" and "inverse exponential
g redshift-distance relation," respectively. Pure Hubble constant
g (...) lies on the straight line.

So write it up.

It was written up years ago. It's called tired light theory. I believe
Zwicky was the first in the 1900s. Though Olber was the first to come up
with the concept, to write on the concept, in the 1800s.

You're surely aware that the accelerating Universe was deemed one of
the greatest achievements of 1998(?) by the journal Science.

Shows that you can't trust the choir to question the preacher.

If that's wrong, you've got something even bigger.

But not something that Science would ever publish.

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

George Dishman wrote in message
...

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

snip higher levels

No, the proof applies if the number is conserved even in
a steady state universe.

Not in Ned's example. But let's look at your version.

Suppose we were at the centre of
a hot steel sphere of constant size, billions of light
years in diameter (silly, I know but it illustrates the
point), the energy of individual photons would be reduced
in transit by Tired Light but the rate of photons arriving
would not. The result would not match what was measured by
FIRAS.

There is no reason that they should. Because you are again assuming
that the CMBR is the result of a cosmic, universal and simultaneous
event (or events).

No, but I am assuming that whatever the source, it is
essentially a blackbody spectrum, i.e. thermally generated

Because you require that the photons all travel cosmic distances before
detection; you are also assuming a distant, essentially simultaneous, cosmic
source from everywhere in the universe.

This is a Big Bang assumption. It could be shoehorned into a
steady-state theory, but it is not a requirement of steady-state theory
or tired light theory. Eddington first calcuated that temperature by
using simple starlight.

It meets my assumption though because he used starlight
to heat interstellar material which then re-radiated
thermally. The above argument then applies.

But Eddington's photons didn't have to travel cosmic distances after
emission. They were local, recent emissions.

For example, in my favorite theory (a Maxwellian/LeSage theory), the
CMBR is simply an EM hum from electrons bound to hydrogen.

But that doesn't produce the spectrum we see,

Sure it does. It's a thermal emission.

hydrogen radiates in discrete lines.

Not thermal emission, it doesn't. You are simply assuming that I'm talking
about a balmer or lyman-type emission from excited atoms.

How does it get to the observd spectrum?

Notice that I didn't say "atomic" hum. I said "electron" hum. Based on the
reduced mass of the electron in bound, ground-state hydrogen.

With the units of divergence of momentum for charge (which is the "natural"
units for an aether theory), the charge to mass ratio is indicative of the
intrinsic frequency of the basic matter particles. The corresponding
wavelength for the electron is:

lambda = m c / q

For the bound electron with a typical relativistic mass of approximately
1E-30 kilograms we get:

lambda = (1.0E-30) (2.99e+8) / (1.602E-19) = 1.87 E-3 meters.

Computing the equivalent blackbody temperature spectrum of this emission
gives:

T = .51 / 100 lambda = 2.73 deg K.

A completely local effect, without any experimental disproof (the
experiments have never tested for local effects, by placing the detectors in
isolation chambers).

Now, my favorite theory may be incorrect. However, even if my theory is not
correct, it doesn't change the fact that you cannot use a BB assumption as
the basis to claim that non-BB theories are not correct.

snip repeat of above

{snip exchange on Zel'dovich}

snip
Anyway, as you can see, I gave you a different argument above.

Hey, I enjoy being proved wrong on that kind of prediction. Even if
your argument was just a repetition of a vague and hand-wavy effort

It gives a quantitative analysis for an example source
temperature.

But not one that is used in tired light theories.

It is in some.

Which ones? I'm not aware of any. (And I mean a tired light theory source
that is actually promoting the tired light theory. Not one of the usual
straw men trotted out by folks like Ned and MTW.)

This is partly why you get what you call
hand-waving answers. There are so many Tired Light
theories, no one analysis applies to all.

Then why do people like Ned and MTW (and dozens on this newsgroup, like
Franz) constantly prattle about a single or a few simplistic arguments
"disprove" all tired light models?

Then again, we can get back to the non-linear, spatial correlations that
arise from tired light.

snip repetition of above arguments

Aladar's claim was that he was the first person ever to
suggest that Tired Light would produce an exponential
relationship between distance and frequency.

Uh, no. What Aladar claimed was that his was the first theory that
included causation. Zwicky's did not.

I spent nearly two years discussing this with him. I won't
start digging out Google references but I can asure you it
took me a long time to convince him he wasn't the first.

Fine. In the one link you did give, Aladar was not arguing the point that
you claim that he was.

I also
pointed out that _his_ theory was falsified by the FIRAS
data. That isn't the same as claiming "*all* Tired Light
theories are the same as Zwicky's."

You claimed that his theory was the same as Zwicky's

No, I never did that.

I don't want to get into this again. Read the link.

{snip the rest of the Aladar argument}


snip

it was a strawman then too.

It is not a strawman. The SN1a data curve was not predicted by the
hubble law -- even the epoch-dependent version. (That is why we have
"dark energy.") It *was* predicted by tired light theories.

I wonder if you mean the same as me. What you say is
true, but unrelated. A strawman is producing a false
version of a theory which can be shown to be false
when the real theory could not.

We agree on the definition of strawman.

I was talking of your
attempts to suggest the red-shift should be proportional
to distance even at high z in Big Bang theories.

I said the *observed* redshift-distance curve was not predicted by the big
bang theorists. As a result we have "dark energy." But that observed
redshift-distance curve *was* predicted by tired light theorists.

{snip}

Again you imply the strawman of expected linearity in the
SNe data.

"Dark energy" was not predicted by the big bang. Dark energy is an ad
hoc modification to the BB, to explain a deviation between the form
of the observed redshift-distance curve versus the theoretical
redshift-distance curve.

Again I don't disagree but your strawman was to imply that
the theoretical redshift-distance in BB is linear.

It is -- not counting the ad hoc modification for cosmic epochs. But we can
get past that, and go directly to:

The form of the observed redshift-distance curve was predicted by
tired light.

Now we are getting somewhere, this is what i would rather
discuss. Which tired light theory predicts this and what
is the formula for the curve?

All tired light theories predict the exponential form of the curve that was
detected. The value of the extinction constant is ad hoc in most of them.
(Just like the value of the dark energy / cosmological constant is an ad hoc
value in the new, improved BB theory.)

What is described as "dark energy" is the unknown
cause of the _deviation_ from the predicted _non-linearity_
which, in the conventional model,

Yes, we agree.

implies expansion is now accelerating.

Only if you refuse to consider the alternative.

That was in reference to the expansion model only of course.

We weren't discussing *only* the expansion model. So, I inserted the
clarifier.

The Hubble Law remains linear.

The question is, does the "Hubble law" reflect the real universe.

No, the question is does the conventional model reflect
the real universe. There's lots more than just the Hubble
Law involved and many tests that it could yet fail.

I sure don't disagree with that statement. However, *this* thread was
limited to the correlation between redshift and distance. Not all the rest
of the "conventional model."

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

George Dishman wrote in message
...

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

"Bjoern Feuerbacher" wrote in
message
...
...

Yes, that's his usual modus operandi. Probably he will soon start
calling you a troll...

Could be, I thought he was trolling when we started.

Wrong again.

We'll see, you are still trying to use a strawman
and it still looks as though your motive is to
generate an argument. When you stop, I'll be
pleased to know my first impression was incorrect.

LOL!

... I've sampled most of Franz's posts and
I'll try to find his quantitative analysis over the
weekend as his conclusion seem a little different to
mine, but my approach was perhaps less general.

Don't sweat too hard. Franz never posted it. However, he did
admit that he had assumed compton scattering to get his numbers.

Since you haven't spoken about specific theories but
discuss Tired Light in general, that's either you
get general answers or he has to illustrate the point
with specific examples.

The basis of that thread was Franz' insistence that he had a proof that
*all* tired light theories were wrong, based on his *one* calculation. He
was attempting to support his claim. *He* brought it up.

That's why I say I'm willing
to consider alternatives to conventional theories but
I'm still waiting for you to identify which alternative
you want to consider. Until you do that, I can only
speak in generalisations too.

Let's speak you your generalization: Tired light theories with exponential
energy removal. You earlier claimed that that was all that you needed to
disprove the theories (both when you were talking to Aladar, and in this
thread).

However, if the issue is now that exponential energy removal theories are
*NOT* all disproved, then let's get back to the observational correlation
between redshift and distance.

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

George Dishman wrote in message
...

"greywolf42" wrote in message
.. .
Bjoern Feuerbacher wrote in message
...

I'm also not entirely sure about this, but I think when he
talks about the "decay" of a photon, he does not mean here
that it is completely lost - he means that its *energy*
"decays".

Items 2 and 3 are two separate arguments. But they're both pretty dippy
arguments, don't you think?

2) doesn't show the working so I can't comment.

That *IS* all there is to the working. So of course you can comment.

It is
valid if it can be shown that there was a minimum value
for the energy of particle k but I don't see that it
follows if the energy loss can be arbitrarily small.

I would have tackled the situation described by 3) in a
different way and I might have applied the method in 3)
to the type of decay described in 2), but then I'm only
an amateur.

The scientific method doesn't care who pays your salary.

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

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


[snip]

"Dark energy" was not predicted by the big bang. Dark energy is an ad
hoc
modification to the BB, to explain a deviation between the form of the
observed redshift-distance curve versus the theoretical redshift-distance
curve.


Again I don't disagree but your strawman was to imply that
the theoretical redshift-distance in BB is linear.

Well, I disagree. True, dark energy was not predicted by the BBT directly.
But it is neither an ad hoc modification of it! The cosmological constant
is essentially a free parameter in the equations of GR. In previous times,
people set it to zero (because there were no observations which showed
differently, and there were some *very* hand waving arguments that it
probably is zero), but when the new measurements of the SNs came in, we
found out that this parameter in
reality is not zero. That's science: determining parameters of a
theory by observations.

Before you can determine a parameter, you need an
equation to put it into, but many laws have started
as empirical correlations and the theory came later.
In fact some consider empirical laws to be the purest
form of science, uncorrupted by the limitations of
our understanding.

I explained this several times to greywolf42, but he simply refuses to
understand my argument...

That I can appreciate. He does seem very determined to
avoid understanding.

OTOH, some alternative models to explain the accelerated expansion, like
e.g. quintessence, I would perhaps call "ad hoc" - because there is
indication at all that such a scalar field exists. It was really only
introduced in order to save some problems in the theory.

That's really what I meant, they are ad hoc mechanisms
to explain the empirical relationship. I used "dark
energy" as a generic term for whatever is causing the
acceleration, which is perhaps not the way it is used
in more professional circles.

The form of the observed redshift-distance curve was predicted by
tired light.


Now we are getting somewhere, this is what i would rather
discuss. Which tired light theory predicts this and what
is the formula for the curve?

And which tired light theory predicted the new data, which shows
(according to the standard GR explanation) that at earlier times, the
expansion was decelerating? (astro-ph/0402512)

Which of the tired light theories agree with all the other established
theories, i.e. GR and QFT, by the way?

If he can come up with one that explains the spectrum
of the CMBR and its dipole moment as well as why the
cosmological red-shift is exponential with distance
he'll do better than anyone else I've talked to on
the subject.

George

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

George Dishman wrote:

"greywolf42" wrote in message
m...


[snip]


"Dark energy" was not predicted by the big bang. Dark energy is an ad
hoc
modification to the BB, to explain a deviation between the form of the
observed redshift-distance curve versus the theoretical redshift-distance
curve.


Again I don't disagree but your strawman was to imply that
the theoretical redshift-distance in BB is linear.

Well, I disagree. True, dark energy was not predicted by the BBT directly.
But it is neither an ad hoc modification of it! The cosmological constant
is essentially a free parameter in the equations of GR. In previous times,
people set it to zero (because there were no observations which showed
differently, and there were some *very* hand waving arguments that it
probably is zero), but when the new measurements of the SNs came in, we
found out that this parameter in
reality is not zero. That's science: determining parameters of a
theory by observations.


Before you can determine a parameter, you need an
equation to put it into, but many laws have started
as empirical correlations and the theory came later.
In fact some consider empirical laws to be the purest
form of science, uncorrupted by the limitations of
our understanding.

Well, but Einstein's equations for GR did *not* come from
empirical considerations (or they were only very vaguely based on
them), but mostly from mathematical arguments and postulates. IIRC,
Einstein had a postulate "an empty spacetime should have curvature
zero". If one drops that postulate (which one essentially *has* to do,
since according to QFT, a space which appears to be empty contains
in reality still vacuum fluctuations), the cosmological constant appears
naturally in the equations.


[snip]


OTOH, some alternative models to explain the accelerated expansion, like
e.g. quintessence, I would perhaps call "ad hoc" - because there is
indication at all that such a scalar field exists. It was really only
introduced in order to save some problems in the theory.


That's really what I meant, they are ad hoc mechanisms
to explain the empirical relationship. I used "dark
energy" as a generic term for whatever is causing the
acceleration, which is perhaps not the way it is used
in more professional circles.

No, you are right, it is indeed used in that way (AFAIK - I am not a
professional myself, but was in close contact to some of them, e.g.
Wetterich). But I think when one talks about the question if "dark
energy" is ad hoc or not, one should distiguish between the different
attempts to explain it (the most prominent are the cosmological constant
and quintessence).


The form of the observed redshift-distance curve was predicted by
tired light.


Now we are getting somewhere, this is what i would rather
discuss. Which tired light theory predicts this and what
is the formula for the curve?

And which tired light theory predicted the new data, which shows
(according to the standard GR explanation) that at earlier times, the
expansion was decelerating? (astro-ph/0402512)

Which of the tired light theories agree with all the other established
theories, i.e. GR and QFT, by the way?


If he can come up with one that explains the spectrum
of the CMBR and its dipole moment as well as why the
cosmological red-shift is exponential with distance
he'll do better than anyone else I've talked to on
the subject.

Well, he'll probably simply ignore that.


Bye,
Bjoern

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

Well, I disagree. True, dark energy was not predicted by the BBT
directly. But it is neither an ad hoc modification of it! The
cosmological constant is essentially a free parameter in the
equations of GR.

You mean, of Relativistic Cosmology. There is no CC in GR. (GR is a subset
of RC.)

Plus, RC is not the big bang theory. (RC is a subset of BB theory.) And
the BB did *NOT* include a cosmological constant for many decades.

In previous times,
people set it to zero (because there were no observations which showed
differently, and there were some *very* hand waving arguments that it
probably is zero),

And it *WAS* zero, in the theory. If it had been in the theory, then there
would have been a lot of hand-wringing over the non-observation of
deviations from linearity.

but when the new measurements of the SNs came in, we
found out that this parameter in
reality is not zero. That's science: determining parameters of a
theory by observations.

So, if we assume for the sake of argument that this was an observational
parameter that had no value (or even a positive, negative or zero
condition). Then this theory is not in as good a shape as competing
theories that predicted the shape and value of the deviation.

Before you can determine a parameter, you need an
equation to put it into, but many laws have started
as empirical correlations and the theory came later.
In fact some consider empirical laws to be the purest
form of science, uncorrupted by the limitations of
our understanding.

Well, but Einstein's equations for GR did *not* come from
empirical considerations (or they were only very vaguely based on
them),

A completely false claim. Einstein changed from his Entwurf of 1913 to the
"modern" GR, solely because of the "observation" of an NNPA of Mercury of
43" per century.

but mostly from mathematical arguments and postulates. IIRC,
Einstein had a postulate "an empty spacetime should have curvature
zero". If one drops that postulate (which one essentially *has* to do,
since according to QFT, a space which appears to be empty contains
in reality still vacuum fluctuations), the cosmological constant appears
naturally in the equations.

Unfortunately, that was Einstein. Not the BB theorists.

[snip]

OTOH, some alternative models to explain the accelerated expansion, like
e.g. quintessence, I would perhaps call "ad hoc" - because there is
indication at all that such a scalar field exists. It was really only
introduced in order to save some problems in the theory.

That's really what I meant, they are ad hoc mechanisms
to explain the empirical relationship. I used "dark
energy" as a generic term for whatever is causing the
acceleration, which is perhaps not the way it is used
in more professional circles.

No, you are right, it is indeed used in that way (AFAIK - I am not a
professional myself, but was in close contact to some of them, e.g.
Wetterich). But I think when one talks about the question if "dark
energy" is ad hoc or not, one should distiguish between the different
attempts to explain it (the most prominent are the cosmological constant
and quintessence).

If they are after the fact (CC and quintessence) they *are* ad hoc.

The form of the observed redshift-distance curve was predicted by
tired light.

Now we are getting somewhere, this is what i would rather
discuss. Which tired light theory predicts this and what
is the formula for the curve?

And which tired light theory predicted the new data, which shows
(according to the standard GR explanation) that at earlier times, the
expansion was decelerating? (astro-ph/0402512)

Why, none. You can't use BB assuptions to disprove tired light ... which
doesn't result in a BB.

Which of the tired light theories agree with all the other established
theories, i.e. GR and QFT, by the way?

LOL! *NO* theory agrees with them all. GR and QFT are in conflict by 50
orders of magnitude!

If he can come up with one that explains the spectrum
of the CMBR

Electron vortex noise from the aether. A local effect due to electrons
bound in hydrogen gas.

and its dipole moment

The motion of the solar system through the aether.

as well as why the
cosmological red-shift is exponential with distance

Any tired light theory. (In this case, the slight imperfection in the
aether.)

he'll do better than anyone else I've talked to on
the subject.

You obviously haven't talked to many people on the subject. Why not try
thinking?

Well, he'll probably simply ignore that.

Nope. I already gave him the answer. But he snipped it, and ignored it ..
as usual.

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