Changes

The Hubble redshift in absorption and emission lines in the spectra of distant cosmic objects, discovered by [[Edwin Hubble]] in 1929, is claimed as a source of evidence for the [[Big Bang theory]].<ref>{{cite web |title=A relation between distance and radial velocity among extra-galactic nebulae |author=Edwin Hubble |date=January 17, 1929 |publisher=Proceedings of the National Academy of Sciences |pages=15: 168–173|url=http://www.pnas.org/content/15/3/168.short |accessdate=June 9, 2013}}</ref> The redshift, the expanded wavelength of light, suggests that these objects are moving away from Earth due to the [[Expanding universe|expansion of the universe]]. It also suggests that the universe is undergoing accelerating expansion for an unknown reason.

The Hubble redshift in absorption and emission lines in the spectra of distant cosmic objects, discovered by [[Edwin Hubble]] in 1929, is claimed as a source of evidence for the [[Big Bang theory]].<ref>{{cite web |title=A relation between distance and radial velocity among extra-galactic nebulae |author=Edwin Hubble |date=January 17, 1929 |publisher=Proceedings of the National Academy of Sciences |pages=15: 168–173|url=http://www.pnas.org/content/15/3/168.short |accessdate=June 9, 2013}}</ref> The redshift, the expanded wavelength of light, suggests that these objects are moving away from Earth due to the [[Expanding universe|expansion of the universe]]. It also suggests that the universe is undergoing accelerating expansion for an unknown reason.

Actually the reason is known and confirmed by Supernova Cosmology Project team in 1998 with accuracy to one standard deviation (the second term of Taylor series of Hubble "constant" as function of time is causing the illusion of accelerating expansion of space with  

Actually the reason is known and confirmed by Supernova Cosmology Project team in 1998 with accuracy to one standard deviation (the second term of [[Taylor series]] of Hubble "constant" as function of time is causing the illusion of accelerating expansion of space with  

:<math>dH/dt=-H_o^2/2</math>,

:<math>\frac{\mathrm{d}H}{\mathrm{d}t}=-\frac{H_o^2}{2}</math>,

where <math>dH/dt</math> is apparent acceleration of expansion of space,  

where <math>{\mathrm{d}H} / {\mathrm{d}t}</math> is apparent acceleration of expansion of space,  

:<math>H_o=c/R_E</math>,

:<math>H_o=\frac{c}{R_E}</math>,

is Hubble constant, <math>c</math> is speed of light in [[vacuum]], and <math>R_E</math> is "Einstein radius", or radius of [[curvature of space]], about 13 billion light years).

is Hubble constant, ''c'' is [[speed of light]] in [[vacuum]], and ''R''_E is "Einstein radius", or radius of [[curvature of space]], about 13 billion light years).

==Alternative Interpretations of the Redshift==

==Alternative Interpretations of the Redshift==

The redshift phenomenon pertains to observation of spectra of [[light]] emitted from luminous bodies such as [[nebulae]] (stellar systems). The true nature of light is however still uncertain. With current body of knowledge, the light can be portrayed as out-spreading electromagnetic wave or as travelling in bullet-like parcels of energy called quanta. Waves have various wavelengths; quanta carry different amounts of energy. Since the same phenomenon can be described by both concepts, it is regarded as evidence that there is some underlying connection between them. This connection is expressed in the very fundamental relation between the energy-content of a quantum and the equivalent wavelength:

The redshift phenomenon pertains to observation of spectra of [[light]] emitted from luminous bodies such as [[nebulae]] (stellar systems). The true nature of light is however still uncertain. With current body of knowledge, the light can be portrayed as out-spreading electromagnetic wave or as travelling in bullet-like parcels of energy called quanta. Waves have various wavelengths; quanta carry different amounts of energy. Since the same phenomenon can be described by both concepts, it is regarded as evidence that there is some underlying connection between them. This connection is expressed in the very fundamental relation between the energy-content of a quantum and the equivalent wavelength:

:''energy x wavelength = constant''     

:''energy x wavelength = constant''     

:<math>E{\lambda} = constant</math>   

:<math>E{\lambda} = \mathrm{constant}</math>   

Because of this relation, two possible effects can be identified:

Because of this relation, two possible effects can be identified:

*a.) Increase of wavelength <math>{\lambda}</math> implies => a decrease in Energy E; If the primary change is in wavelength, then the red-shifts are probably velocity-shifts, what is nowadays prevailing interpretation.     

*a.) Increase of wavelength <math style="vertical-align:-10%;">{\lambda}</math> implies a decrease in Energy ''E''; If the primary change is in wavelength, then the red-shifts are probably velocity-shifts, what is nowadays prevailing interpretation.     

*b.) Reduction of Energy E implies => an increase of wavelength <math>{\lambda}</math>; The primary change might be also a loss of energy, which would be observed as redshift.   

*b.) Reduction of Energy ''E'' implies an increase of wavelength <math style="vertical-align:-10%;">{\lambda}</math>; The primary change might be also a loss of energy, which would be observed as redshift.   

As in either case it is only increased wavelength what is observed, there is no direct way of determining which of the two above effects is fundamental.  

As in either case it is only increased wavelength what is observed, there is no direct way of determining which of the two above effects is fundamental.  

In order to be able to distinguish between two alternatives, a critical empirical test is needed that would establish whether or not a luminous body is receding.<ref name="Observational Approach">{{cite web

In order to be able to distinguish between two alternatives, a critical empirical test is needed that would establish whether or not a luminous body is receding.<ref name="Observational Approach">{{cite web

[[Category:Astronomy]]

[[Category:Astronomy]]