Non-Doppler Redshift

[Vanilor]

In a discussion about the Big Bang on another forum, I was directed to an article that proposed an alternative explanation for the redshift we observe due to the expansion of the universe.

Astrophysical observations show that the electromagnetic radiation originating from cosmological objects is often redshifted. Except for some hypothesis such as assuming that it is a gravitational redshift, this has always been interpreted as a Doppler shift. To date, the interaction of light with interstellar gas has not been seriously considered as a possible mechanism responsible for the observed redshift, because no known forward scattering process could be demonstrated to lead to an effect compatible with common astronomical observations.

A New Non-Doppler Redshift (http://www.newtonphysics.on.ca/HUBBLE/Hubble.html)

Thoughts? The author does not seem to be a proponent of the steady-state universe, but is it possible that interstellar gas creates the redshift we now observe, or at least interferes with our calculations of the expansion of the universe?

[skepticalbip]

Whoever referenced that article was possibly referring to the idea of "tired light".

http://en.wikipedia.org/wiki/Tired_light
Tired light is a hypothetical redshift mechanism proposed as an alternative explanation for the redshift-distance relationship. Tired light was first proposed in 1929 by Fritz Zwicky [1] who suggested that photons might slowly lose energy as they travel vast distances through a static universe by interaction with matter or other photons, or by some novel physical mechanism. Since a decrease in energy corresponds to an increase in light's wavelength, this effect would produce a redshift in spectral lines that increase proportionally with the distance of the source. The term "tired light" was coined by Richard Tolman in the early 1930s [2].
................

[Smullyan-esque]

Here's a key problem with this idea: If there is some mechanism that causes light to lose energy aside from doppler and gravitational red-shifting, it MUST be a uniform mechanism, because the emission and absorbtion spectra we observe are not "smeared out". The mechanisms described in the links above are non-uniform effects. They both operate in term of interaction with other particles. Over long distances, you would necessarily get some photons that had interacted with a more-than-average number of other particles, and some photons that had interacted with a less-than-average number of other particles. This would give you a binomial distribution of redshift, not a clear, sharp redshift, like what we actually observe.

There still might be some other mechanism for causing a red-shift. But it can't be the ones described above. And, in the absence of a good competing theory, we are stuck with the mechanisms we know about: Doppler and Gravitational.

[Stinger]

Whoever referenced that article was possibly referring to the idea of "tired light".

http://en.wikipedia.org/wiki/Tired_light The Tired Light theory is similar to ID in that it is only "believed" by people who's personal belief's conflict with accepted scientific theories.

[skepticalbip]

The Tired Light theory is similar to ID in that it is only "believed" by people who's personal belief's conflict with accepted scientific theories.I understand and I am not a proponent of the "tired light theory". It just seemed to me that this is what whoever was talking about other explanations for the red shift (other than doppler or gravitational shift) could have been referring to.

[daemonia]

If so you could not get a blue shifted galaxy next to a red shifted galaxy... same interstellar gas right... seems an attempt doomed to fail.

[Vitalstatistix]

I only glanced at it, but I think it's actually compton scattering instead of tired light. Quoting from wikipedia..

"Compton scattering has on occasion been proposed as an alternative explanation for the phenomenon of the redshift by opponents of the Big Bang theory, although this is not generally accepted because the influence of the Compton scattering would be noticeable in the spectral lines of distant objects and this is not observed."

[Koyaanisqatsi]

What I love about these kinds of things is that they are usually about a very narrow, possible sample under unique conditions that are never uniform throughout the universe, yet that doesn't stop cult members from lifting them up as implied "failures" of science.

It's always something like, "This particular, very specific phenomenon may be caused by something else, therefore all of science is bunk."

:rolleyes:

And the most pathetic thing about it is that they think they're using science to discredit Science.

:huh:

[Vitalstatistix]

Well in all fairness this was back in 88 (COBE was 89) and he's not really in the same league with your typical crank. Presents his material a lot more professionally.

[Corona688]

Since when was redshift the doppler effect? It's analagous, but hardly the same thing.

[Schneibster]

Errrmmmm, "tired light" would violate conservation of energy.

[Bob K]

Errrmmmm, "tired light" would violate conservation of energy.

How so?

Wouldn't energy dissipating from any physical process would be conserved by Conservation Law of Energy/Conservation Law of Matter & e = mc2 & m = e/c2?

[Koyaanisqatsi]

Well in all fairness this was back in 88 (COBE was 89) and he's not really in the same league with your typical crank. Presents his material a lot more professionally.

No doubt, but my point was more to those who co-opt these possible anomolies and then falsely extrapolate them to indict "science" in general.

[Friar Bellows]

Errrmmmm, "tired light" would violate conservation of energy.

That's a dopey criticism. You think proponents of "tired light" hypotheses haven't proposed some physical process that explains where the energy goes? Usually that's where they start! Even the Wikipedia article (http://en.wikipedia.org/wiki/Tired_light) touches on some of the mechanisms of energy loss of photons after they are emitted by their sources. The real criticism of "tired light" models has to do with their incompatibility with observational data, from time dilation of supernova light curves to the failure to reproduce a blackbody spectrum in the cosmic background radiation.