Difference between revisions of "Doppler Shift"
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The '''Doppler Shift''' of light is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It was named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. Light waves from a moving source experience the Doppler shift as either a red shift or blue shift in the light's frequency. When an object approaches the observer its light will ''blue shift'', and when it recedes from the observer its light will ''red shift''. | The '''Doppler Shift''' of light is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It was named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. Light waves from a moving source experience the Doppler shift as either a red shift or blue shift in the light's frequency. When an object approaches the observer its light will ''blue shift'', and when it recedes from the observer its light will ''red shift''. | ||
| − | Discussions on this topic ask how the galaxies can be red shifted if they are not receding away from the observer at very high speeds. An answer to this query | + | Discussions on this topic typically ask how the galaxies can be red shifted if they are not receding away from the observer at very high speeds. An answer to this query is that the Doppler Shift of light is only one interpretation for the red shift. A page at the University of North Carolina explains: |
http://www.cs.unc.edu/~plaisted/ce/redshift.html | http://www.cs.unc.edu/~plaisted/ce/redshift.html | ||
Revision as of 01:42, 10 June 2020
The Doppler Shift of light is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It was named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. Light waves from a moving source experience the Doppler shift as either a red shift or blue shift in the light's frequency. When an object approaches the observer its light will blue shift, and when it recedes from the observer its light will red shift.
Discussions on this topic typically ask how the galaxies can be red shifted if they are not receding away from the observer at very high speeds. An answer to this query is that the Doppler Shift of light is only one interpretation for the red shift. A page at the University of North Carolina explains:
http://www.cs.unc.edu/~plaisted/ce/redshift.html
“ As noted earlier, a galaxys' redshift may not be a Doppler shift, it is the currently commonly accepted interpretation of the red shift, but there can be and are other interpretations. A galaxys' redshift may be a fundamental property of the galaxy. Each may have a specific state governed by laws, analogues to those in quantum mechanics that specify which energy states atoms may occupy. Since there is relatively little blurring on the quantization between galaxies, any real motions would have to be small in this model. Galaxies would not move away from one another; the universe would be static instead of expanding.
This model obviously has implications for our understanding of redshift patterns within and among galaxies. In particular it may solve the so-called "missing mass" problem. Conventional analysis of cluster dynamics suggest that there is not enough luminous matter to gravitationally bind moving galaxies to the system. ”
Jacques Moret-Bailly
Physics Professor Jacques Moret-Bailly of the University of Burgundy has written a number of papers on physical alternatives to Doppler Shift.
Correspondence of classical and quantum irreversibilities
Abstract
“ It appears that Raman scattering in extremely low-pressure gases shifts the frequency of the incident light, is space coherent and thus may be confused with the Doppler effect: the Raman scattering produces at least a part of the galactic redshift; the expansion of the universe is reduced or possibly cancelled. ”
Conclusion
“ A notable minority of astrophysicists think that the Doppler effect cannot explain all observed redshifts [7, 8], but they were unable to find an alternative physical effect because usual studies of optics consider time-coherent waves: considering that a wavelength is a unit of length, a lineshift with the condition of space and time coherence can only be produced by a Doppler effect. We have described a possible alternative which also produces low energy radiation ”
The coherent Raman scattering in astrophysics; application to a new model of quasar
“ This linear effect named ”Incoherent Light, Coherent Raman Scattering” (ILCRS) may be confused with a Doppler effect in astrophysics; it explains all optical properties of the quasars, including the debatable ones, in particular the width of the BAL lines, the infrared thermal radiation attributed to hot dust, and the spectral discrepancies attributed to a variation of the hyperfine constant. ”