[Vern (OP)]

Lyndon Asmore is an advocate of the Tired Light Theory. He is still publishing and responding to observational problems that would seem to rule out Tired Light as the cause of the cosmic red shift. I always thought the time dilation observed in distant 1A Supernova events was fatal to the Tired Light concept.

What do you think?

Tired Light is an alternative theory to that of the expanding Universe. This theory explains the experimental evidence without resorting to the 'cosmological constants' or 'vacuum energy' that are essential to the theory of the expanding Universe.

Experiment tells us that photons of light from distant galaxies have a longer wavelength on arrival than when they set off. Since red light has a longer wavelength than blue light, we say that they have been 'redshifted'. The Theory of the Expanding Universe explains this as space expanding and stretching the photons as it does so. In Tired Light we say that the photons lost energy during their journey to us by bumping into electrons on the way.

The Tired Light Theory (that redshift is due to electron interaction) is supported by the fact that measured values of the Hubble constant, H are exactly equal to a combination of the parameters of the electron. This is known as 'Ashmore's Paradox'. If, in the expanding Universe, the expansion is not related to the electron then why is the Hubble constant found experimentally to be related to the electron?

When sending digital pulses down a fibre optic, monochromatic light is used as different frequencies travel at different speeds down the fibre. If white light is used, this leads to 'pulse broadening .' In supernovae 'time dilation' muticolour light curves are considered. However, a supernova burst is just a digital pulse and 'pulse broadening' is not taken into consideration when testing Tired Light models [1].

This produces an effect similar to 'Time Dilation.' Different frequencies of radiation are known to travel through space at different speeds [2] as is shown by gamma ray bursts. All frequencies may well start off at the same time but they will arrive here on Earth at different times - and the greater the redshift, the greater the pulse broadening! Who needs expansion and relativity - Tired Light.

Recent Gamma-ray Imaging indicates that different frequencies of light might propagate at different speeds in space. Ashmore claims that lends credence to his hypothesis.

The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescope found that high-energy photons of gamma radiation from a distant galaxy arrived at Earth four minutes after lower-energy photons, although they were apparently emitted at the same time. If correct, that would contradict Einstein's theory of relativity, which says that all photons (particles of light) must move at the speed of light.

[Bored chemist]

This is what Wiki has to say on the matter.
Any "tired light" mechanism must solve some basic problems, in that the observed redshift must:

admit the same measurement in any wavelength-band
not exhibit blurring
follow the detailed Hubble-relation observed with Supernova data (see accelerating universe)
explain associated time dilation of cosmologically distant events.
As part of a broader alternative cosmology, other observations that need explanation include:

the detail observations of the cosmic microwave background radiation
the abundance of light elements
large-scale structure statistics
To date, no established mechanism to produce such a drop in energy has been proposed that reproduces all the observations associated with the redshift-distance relation. "

Has anything changed? If not then the answer to the question is that we can rule out tired light.

[Vern (OP)]

I'm not a big fan of the Tired Light theory, but all of the objections cited from the Wiki article have been addressed, to me it seems, successfully. I see one remaining thing that needs to be observed to give the theory some footing. If the mechanism of the red shift is the interaction of light with electrons, as Ashmore proposes, then we should see the high end of the spectrum shifted by a different amount than the low end.

Ashmore's equation includes the wave length of the shifted light. The amount the wave length changes is proportional to the wave length.

[Bored chemist]

As you say, it doesn't actually fit the data for short wavelengths.
"If the mechanism of the red shift is the interaction of light with electrons, as Ashmore proposes, then we should see the high end of the spectrum shifted by a different amount than the low end."
As far as I'm aware,  we don't.


From Ashmore's own page about the "paradox"
"Does the paradox work in other systems of units?
The honest answer is that H having the same magnitude as hr/m is a 'quirk' of the SI system of units. The expression of H = 2nhr/m works in any system of units and is perfectly valid. The paradox, H = hrm in magnitude is a 'coincidence' because the value of 'n' (the number of electrons in each cubic metre of space) is approximately unity."

Even the author says it's a fluke, not a paradox.

As far as I can see there's nothing really there- it's all smoke and mirrors.
Here's another example.
"The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescope found that high-energy photons of gamma radiation from a distant galaxy arrived at Earth four minutes after lower-energy photons, although they were apparently emitted at the same time. If correct, that would contradict Einstein's theory of relativity, which says that all photons (particles of light) must move at the speed of light."
Einstein didn't say it, Maxwell did, but, what they said was thet the speed of electomagnetic radiation in a vacuum is constant.
However, Ashmore claims that there's stuff in space which slows down light- specifically he makes up a relation that (if it were valid) would indicate that there's roughly 1 electron per cubic metre.
Once you have anything other than a perfect vacuum then you have a refractive index- andf that will be wavelength dependent.
Since nobody suposes that interstellar space is a perfect vacuun (just a jolly good one) there's no case to answer.
However the fact that the spectra from distant objects are shifted in exactly the way you would expect for a receding object still needs to be explained. If delta lambda/ lambda is constant how come the change in aparent speed (4 minutes in the time it takes to get a signal from a distant galaxy - how ever many thousands or millions of years that is) is so small when the ratio of the wavelengths - roughly a million fold- is so big?

[Vern (OP)]

I have a feeling your analysis is correct. But I'm still keeping a look out for a spectrum study that looks for differences in the amount of red shift between the high and low end of the spectrum. This is a clear prediction that should be testable.

[Vern (OP)]

In this colorful presentation that Ashmore did at the CCC2 Conference he claims that the direct physical evidence presently available indicates that the universe is not expanding.

What does represent Direct Physical evidence of the dynamics of the universe?
    1. The average separation of Hydrogen Clouds?
    2. The average separation of galaxies?
    3. The average temperature. Is it increasing, decreasing or
       staying the same?

The evidence indicates that the distance between hydrogen clouds is not increasing.
The average separation of galaxies is not increasing.
The average temperature of the universe is increasing.

So I am still not ready to accept the current cosmology as it now stands.

[Bored chemist]

It goes dark at night- no great revelation there.
Do you understand that this means one of three things.
There's something odd about our bit of the universe
The universe hasn't been around forever or
The universe is finite in its extent?

If the universi if finite (in time or space) the a big bang looks like a really good candidate.
Does any other model work so well and so easilly?

[Vern (OP)]

It goes dark at night- no great revelation there.
Do you understand that this means one of three things.
There's something odd about our bit of the universe
The universe hasn't been around forever or
The universe is finite in its extent?

I don't understand that the fact that it gets dark at night is an argument favouring the BB theory. To me it is just the opposite. If we accept the notion that a vastly greater size universe would cause blazing light, we have to also realize that 50 billion light years worth of that universe would cause some heating of space debris. That leads to the realization that the CMB is simply the temperature of space.

Nor does it mean that the universe must be finite in size. Starlight may be attenuated by becoming matter as it interacts with space debris, as Tired Light advocates suggest.  The same mechanism that increases the wavelength may attenuate the light. []