A cosmological redshift occurs when the light received from distant objects is shifted in such way that the wavelength of the light we are seeing is longer than the wavelength of the light that was emitted by the object we are looking at. This is like hearing the siren of a fire truck shift to a lower pitch as it moves away from us and the difference in pitch is an indication of how fast it is moving. However, the cosmological redshift has nothing to do with motion as we normally experience it. Instead, cosmologists assume it is defined by the relative separation of parts of the universe and not by motion “outward” into preexisting space.
It was first observed in 1929 when Edwin Hubble measured the redshifts of a number of distant galaxies and their relative distances. When he plotted redshift against their relative distance, he found that it increased as a linear function of distance. The only viable explanation for this observation available at that time was that the universe was expanding.
The relationship between distance the expansion of the universe is called Hubble law which states the rate at which galaxies are receding is directly related to their distance or V = Ho D where “V” is the velocity and “H” is Hubble’s constant and “V” is their velocity which is determined by the magnitude of the redshift.
Hubble law is important because it gives cosmologists a way of determining the age of the universe because if one knows the rate at which it is expanding one can project its expansion back in time to determine when it began.
However, many variables could affect the magnitude of a redshift and therefore the estimates of rate of the universe’s expansion and the calculations of its age based on it.
For example, light would be affected by interstellar dust causing its wavelength and the magnitude of its redshift to increase. However, because interstellar dust is not uniformly disturbed throughout space its affects on the redshift would be non-linear with respect to what it would have been if it had not been there. This non-linear relationship allows cosmologist to distinguish a redshift caused by dust and one caused by the motion of its source.
Another possible was put forth by Einstein in an address “Aether and the theory of Relativity†he delivered on May 5th 1920 at the University of Leyden Germany where he indicated that The General Theory of Relativity predicts that “space is endowed with physical qualitiesâ€.
“Recapitulating, we may say that according to the General Theory of Relativity space is endowed with physical qualities; in this sense, therefore, there exists Aether. According to the General Theory of Relativity space without Aether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense. But this Aether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts, which may be tracked through time. The idea of motion may not be applied to it.â€
In other words he tells us that if one accepts the validity of the General Theory of Relativity one must also accept the fact that space contains a physical or a ponderable media. Additionally he tells us that it cannot be composed parts that could be tracked through time which is the definition of a particle.
However if light is propagated on a medium that does not consists of parts made up of particles why does it at times take the form of one.
The answer can be found in the article “The Photon: a matter wave?†Oct 1, 2007 which showed that its photonic or particle properties can be derived in terms of the resonant properties matter wave moving on the continuous “surface” of a three dimension space manifold with respect to a fourth *spatial* dimension.
Einstein gave us the ability to do this when in terms of his Special and General Theories of Relativity he qualitatively and quantitatively defined the geometric properties of a space-time universe in terms of the equation E=mc^2 and the constant velocity of light. This is because it allows one to redefine a unit of time he associated with energy in it to unit of space in a universe consisting of only four *spatial* dimensions.
In other words by defining the geometric properties of a space-time universe in terms of the equation E=mc^2 and the constant velocity of light he provided a qualitative and quantitative means of redefining his space-time universe in terms of the geometry of four *spatial* dimensions.
Briefly that article showed the four conditions required for resonance to occur in a classical environment, an object, or substance with a natural frequency, a forcing function at the same frequency as the natural frequency, the lack of a damping frequency and the ability for the substance to oscillate spatial would meet in one consisting of a continuous non-quantized field of energy/mass.
The existence of a continuous non-quantized field of energy would provide the substance or medium required for the propagation of a matter wave thereby fulfilling one of the requirements for classical resonance to occur.
These oscillations would be caused by an event such as the decay of a subatomic particle or the shifting of an electron in an atomic orbital. This would force the continuous non-quantized field component of space to oscillate with the frequency associated with the energy of that event.
However, the oscillations caused by such an event would serve as forcing function allowing a resonant system or “structure” to be established four-dimensional space.
Classical mechanics tells us the energy of a resonant system or structure can only take on the discrete quantized values associated with its fundament or a harmonic of its fundamental frequency.
Therefore these resonant systems in four *spatial* dimension are responsible for the discrete energies of all quantum systems.
Additionally it defines a physical link between the wave properties of light because it derives one in terms of the other.
Yet if this were the reason for the existence of the wave and photonic or particle properties of light then it is possible that its energy could be dissipated by interaction with the field properties of space.
The concept was first proposed in 1929 by Fritz Zwicky, who suggested that if photons lost energy over time through collisions with other particles in a regular way, the more distant objects would appear redder than more nearby ones. Zwicky himself acknowledged that any sort of scattering of light would blur the images of distant objects more than what is seen.
This “Tired Light” concept of energy loss associated with the red shifting of photons by its interaction with space has been dismissed by many because no Compton scattering is observed in them.
Compton scattering is a type of scattering that X-rays and gamma rays undergo in matter. The inelastic scattering of photons in matter results in a decrease in energy (increase in wavelength) of an X-ray or gamma ray photon, called the Compton Effect. Part of the energy of the X/gamma ray is transferred to a scattering electron, which recoils and is ejected from its atom (which becomes ionized), and the rest of the energy is taken by the scattered, “degraded” photon.
Inverse Compton scattering also exists, where the photon gains energy (decreasing in wavelength) upon interaction with matter. Since the wavelength of the scattered light is different from the incident radiation, Compton scattering is an example of inelastic scattering, but the origin of the effect can be considered as an elastic collision between a photon and an electron. The amount the wavelength changes are called the Compton shift.
Many feel it demonstrates that light cannot be explained purely as a wave phenomenon because Thomson scattering or the classical theory of an electromagnetic wave scattered by charged particles, cannot explain high intensity shifts in wavelength.
The reason why many astronomers believe the entire redshift of a star is the result of its movement away from an observer is because as just mentioned classical theory of charged particles interacting with an electromagnetic wave, cannot explain changes in wavelength or the redshifting of high energy photons associated with gamma rays.
Therefore, if the red shift was caused by an interaction of a photon with particles in space one should observe Compton scattering in red shifted light. Since no Compton scattering is observed in light coming from a star it is assumed by many astronomers it can only be caused by the movement of an object away from an observer because as mentioned earlier it is the only way they can explain it.
However, as was shown in the article “The Photon: a matter wave?†the quantum mechanical properties of photons and charge particles are the result of a resonant “system” generated by a matter wave moving through a continuous field component of space.
Therefore, the reason no Compton scattering is observed in red shifted light may be because as mentioned earlier of particles such as photons and electrons is dissipated by an interaction of their wave properties with a continuous field energy and not with particles and therefore no Compton scattered would be observed in them.
However, this would mean the assumption of many cosmologists that a redshift can only be caused by the expansion of space between the time the light was emitted, at