Lights Propagation

[Little Bang]

HOW do we know for certain that the existence of space does not resist the propagation of light in such a way as to cause red shift?

[phision]

I love this question, it's one I've been thinking about for a while, and it has significant implications for bang big cosmology! :Guns:

[JMJones0424]

HOW do we know for certain that the existence of space does not resist the propagation of light in such a way as to cause red shift?

 

We don't just observe redshift correlated with distance. We also observe time dilation correlated with distance. As far as I know, there are no mainstream explanations for both observations other than spacetime expansion. Observed time dilation correlated with distance refutes all tired light models. However, coldcreation has a thread here and a website where he proposes a geometric explanation of observed redshift and time dilation.

[Little Bang]

I'll read CC's website but I doubt it will show convincing evidence of time dilation correlated with distance. As far as the OP, just because we find evidence of red shift locally is not a guarantee that it will be true over a million light years.

[CraigD]

HOW do we know for certain that the existence of space does not resist the propagation of light in such a way as to cause red shift?

It’s a given that we know nothing in science with absolute certainty, so we don’t know for certain that “space does not resist the propagation of light” – a feature of a class of theories commonly termed “tired light”. However, despite serious work on them since the first were proposed ca. 1929, no tired light theory to date has survived experimental testing.

 

There’s a lot of literature on the subject, and a lot of technical background needed to understand it. Before proposing a new one, its wise, I think, to thoroughly read and understand the literature.

 

I’ve not done so, but the little study I have done suggest that the greatest difficulties is explaining the Hubble flow redshift as resulting from other than the usual recessional velocity and metric expansion of space, such as with a tired light theory, you’ve got to have a workable model of the universe in which there is not Hubble flow – what Hubble and Tolman are quoted in the wikipedia article calling “a static Einstein model of the universe”.

 

In summary, we can’t know that no tired light theory can be successful, but we do know that none yet have been, and that any that does would have to overcome some profound conceptual challenges.

[Little Bang]

Your post is correct Craig, TY.

[LaurieAG]

It’s a given that we know nothing in science with absolute certainty, so we don’t know for certain that “space does not resist the propagation of light” – a feature of a class of theories commonly termed “tired light”. However, despite serious work on them since the first were proposed ca. 1929, no tired light theory to date has survived experimental testing.

 

There’s a lot of literature on the subject, and a lot of technical background needed to understand it. Before proposing a new one, its wise, I think, to thoroughly read and understand the literature.

 

I’ve not done so, but the little study I have done suggest that the greatest difficulties is explaining the Hubble flow redshift as resulting from other than the usual recessional velocity and metric expansion of space, such as with a tired light theory, you’ve got to have a workable model of the universe in which there is not Hubble flow – what Hubble and Tolman are quoted in the wikipedia article calling “a static Einstein model of the universe”.

 

In summary, we can’t know that no tired light theory can be successful, but we do know that none yet have been, and that any that does would have to overcome some profound conceptual challenges.

 

Good points CraigD,

 

A couple of years ago I suggested that observations be made from a point that was 'stationary' relative to our suns rotation around the Milky Ways galactic center and I think you worked out that the velocity required for such a trajectory was within our current technical capabilities. Please correct me if I am recalling things incorrectly.

 

http://en.wikipedia.org/wiki/Hubble_flow

 

Combining his measurements of galaxy distances with Vesto Slipher and Milton Humason's measurements of the redshifts associated with the galaxies, Hubble discovered a rough proportionality between redshift of an object and its distance. Though there was considerable scatter (now known to be caused by peculiar velocities - the 'Hubble flow' is used to refer to the region of space far enough out that the recession velocity is larger than local peculiar velocities).

http://en.wikipedia.org/wiki/Peculiar_velocity

 

In galactic astronomy, the term peculiar motion (or peculiar velocity) refers to the motion of an object (usually a star) relative to a local standard of rest.

 

I don't know about tired light but after 80 years it appears that the real challenge is not that conceptual or profound.

 

We will never know either way if we cannot be bothered to take a look.

[sigurdV]

HOW do we know for certain that the existence of space does not resist the propagation of light in such a way as to cause red shift?

I dont think we know anything for certain...theories rests ultimately on unprovable principles.

So why dont you form a theory by assuming "that space resists the propagation of light in such a way as to cause red shift",

and work out the consequences of the assumption in order to find ways to test your theory?