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Offline Fluid_thinker

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Hubble Expansion - Proved???
« on: 02/03/2009 14:27:13 »
We depend on Hubble Redshift as a key factor in our modern 'expansion' view of cosmology

Are we absolutely sure that Hubble Redshift is due to expansion?


 

Offline DoctorBeaver

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Hubble Expansion - Proved???
« Reply #1 on: 02/03/2009 14:41:53 »
I don't think we can be absolutely sure of anyuthing. But it certainly fits with what we observe and it's the best candidate so far.
 

Offline Fluid_thinker

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Hubble Expansion - Proved???
« Reply #2 on: 02/03/2009 14:47:44 »
The Tired Light Theory suggests that redshift is due to electron interaction.

This 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.

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?
 

Offline Vern

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Hubble Expansion - Proved???
« Reply #3 on: 02/03/2009 14:54:28 »
Do you have a reference for the electron's relation to the Hubble constant. There have been several changes to the Hubble constant in the past.

I did a little search and turned up this link.

Ashmore's Paradox


Quote from: the link
"Experimental results show that the  Hubble constant, H is the same as hr/m for the electron in each cubic metre of space. Therefore the Universe is not expanding".

This is turning up something that might be detectable. It is the same question I was trying to resolve in another thread. Question: Does the red shift in light from distant galaxies have a greater red shift than blue shift?

Edit: Let me say the question differently: Does the red-light portion of the spectrum have a greater red shift than the blue-light portion of the spectrum? Of course there is no blue shift :)

Quote from: the link
This means that red light, which has a long wavelength, undergoes a greater shift in wavelength than blue light, which has a short wavelength, so that the ratio,   Δλ/ λ has the same value for both.

In the Tired Light Theory, the number of collisions made by each photon depends upon its collision cross section, σ. This represents the probability of a photon being absorbed by the electron. We know the photoabsorption collision cross section for a photon - electron interaction from experiments carried out by the interaction of low energy X rays with matter and it depends upon the radius of the electron and the wavelength of the photon.

  collision cross section, σ = 2x(classical radius of electron,  r)x(wavelength of photon, λ)

or                                                        σ = 2r λ
« Last Edit: 02/03/2009 16:07:58 by Vern »
 

Online Bored chemist

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Hubble Expansion - Proved???
« Reply #4 on: 02/03/2009 19:38:15 »
The tired light theory has major problems. They are listed in the wiki article but here's the precis.
"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. Scattering by known mechanisms from gas or dust does not reproduce the observations. For example, scattering by any mechanism would blur an object more than observed.
In general, cosmologists consider classical tired light models to have too many problems to be worth serious consideration.[11]
Tired light alone does not provide a full cosmological explanation and so cannot reproduce all the successes of the standard big bang cosmology.
No tired light theory is known that by itself correctly accounts for the observed time dilation of distant supernovae light curves [12], the black body spectrum or anisotropy of the cosmic microwave background, and the observed change in the morphology, number count, and surface brightness of high redshift galaxies and quasars. Furthermore, the fact that the age of the oldest stars is roughly equal to the inverse of the Hubble constant emerges naturally from a Big Bang cosmology, but is an unexplained coincidence with most tired light models"
 

Offline Vern

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Hubble Expansion - Proved???
« Reply #5 on: 03/03/2009 19:57:45 »
Quote from: Bored Chemist
the fact that the age of the oldest stars is roughly equal to the inverse of the Hubble constant emerges naturally from a Big Bang cosmology, but is an unexplained coincidence with most tired light models"
This one would be a problem for the Big Bang theory, it seems to me. This would imply that no more than one life cycle of stars has occurred. We know that several star-life cycles are necessary to produce all the heavy elements.

Of all the well known problems with the Tired Light scheme, the one I see most difficult to explain is the apparent time dilation of type 1A novas.
 

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Hubble Expansion - Proved???
« Reply #5 on: 03/03/2009 19:57:45 »

 

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