Light fatigue

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Light fatigue , also known as photon aging , is a physical hypothesis that was put forward to explain the cosmological redshift that occurs in distant celestial bodies in accordance with a static universe . A loss of energy in the photons of light on the way from the source to the observer was considered to be the cause, but no convincing physical mechanism could be given for this. Experimental results speak clearly in favor of the expansion of the universe , ie the expansion of space according to the general theory of relativity , and against a static universe. Light fatigue is therefore not considered as a serious alternative by the vast majority of scientists.

History of the hypothesis and attempts to justify it

At the beginning of the 20th century, Max Planck found the formula , the basis of quantum physics . It says that electromagnetic waves come in indivisible packets, and the higher the frequency of the wave, the more energy the packets have. As a result, light that loses energy (“fatigues”) would shift its frequency to red.

The astronomer Edwin Hubble discovered in 1929 that the further away they are from us, the more the light from galaxies shifts to red. If the galaxies moved away from the measuring device during the measurement, such a shift is to be expected.

In the same year as Hubble, Fritz Zwicky offered an alternative interpretation of this observation, namely that light loses energy in proportion to the distance traveled . He initially suspected that "gravitational friction", an interaction with matter via gravity , could be responsible. The physicist Robert Andrews Millikan also praised the elegance of this idea in a letter to Grote Reber dated May 15, 1952 : "I agree with you that the hypothesis of light fatigue is simpler and less irrational ."

In contrast to the big bang theory , the theory of light fatigue would suggest a static universe . (The concept of a static universe must not be confused with the steady-state theory , since according to the latter, the redshift is based on the expansion of space, as in the big bang theory.)

Various mechanisms for explaining light fatigue have been proposed, for example as a scattering effect ( Compton effect ), as a side effect of quantum mechanics by de Broglie or LaViolette.

Current status

Light fatigue was discussed as a possible cause of the cosmological redshift until around the middle of the 20th century, but thereafter it was increasingly viewed by cosmologists as not applicable. Due to the experimental confirmations and the theoretical consistency of the expansion of the universe , models of light fatigue are only represented outside of the scientific mainstream. Arguments against light fatigue are for example:

  • The observed duration of supernovae correlates with redshift, which is consistent with expansion, and contradicts light fatigue.
  • "Tolman's test of surface brightness" says that in an expanding universe, celestial bodies or galaxies that are further away would have to lose brightness, while in a static universe the brightness remains the same or only decreases to a much lesser extent. In fact, a decrease was observed in accordance with expansion.
  • The observed thermal spectrum of the cosmic background radiation (black body radiation) is incompatible with light fatigue, because the photon density would remain the same if this hypothesis were valid and a redshift would make the spectrum non-thermal. The model of the expanding universe, on the other hand, guarantees that the background radiation continues to retain the properties of blackbody radiation.
  • With scattering as the cause of light fatigue, the image of distant objects would appear blurred, which is not observed.

Web links

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  1. ^ A b Charles Soap: "Tired-Light" Hypothesis Gets Re-Tired . ScienceNow. June 28, 2001. Archived from the original on January 21, 2012. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved December 16, 2011. @1@ 2Template: Webachiv / IABot / news.sciencemag.org
  2. ^ Zwicky, F .: On the Red Shift of Spectral Lines through Interstellar Space . In: PNAS . 15, 1929, pp. 773-779.
  3. ↑ The Biblical Astronomer vol. 14, no 108, spring 2004, p.33 (PDF; 419 kB)
  4. ↑ JR Croca: Beyond noncausal quantum physics . In: Modern Nonlinear Optics , Part 2, Second edition (= Advances in Chemical Physics , vol. 119), Wiley, New York 2001, ISBN 0-471-38931-5 , p. 501 ff., In particular p. 531 ff. ( limited preview )
  5. ↑ Laviolette, PA: Is the universe really expanding? . In: The Astrophysical Journal . 301, No. 1, 1986, pp. 544-553. bibcode : 1986ApJ ... 301..544L .
  6. ↑ Goldhaber et al .: Timescale Stretch Parameterization of Type Ia Supernova B-Band Light Curves . In: The Astrophysical Journal . 558, No. 1, 2005, pp. 359-368. arxiv : astro-ph / 0104382 . bibcode : 2001ApJ ... 558..359G . doi : 10.1086 / 322460 .
  7. ^ Foley et al .: A Definitive Measurement of Time Dilation in the Spectral Evolution of the Moderate-Redshift Type Ia Supernova 1997ex . In: The Astrophysical Journal . 626, No. 1, 2005, pp. L11-L14. arxiv : astro-ph / 0504481 . bibcode : 2005ApJ ... 626L..11F . doi : 10.1086 / 431241 .
  8. ↑ Blondin et al .: Time Dilation in Type Ia Supernova Spectra at High Redshift . In: The Astrophysical Journal . 682, No. 2, 2008, pp. 724-736. arxiv : 0804.3595 . bibcode : 2008ApJ ... 682..724B . doi : 10.1086 / 589568 .
  9. ↑ a b Lubin, Lori M .; Sandage, Allan: The Tolman Surface Brightness Test for the Reality of the Expansion. IV. A Measurement of the Tolman Signal and the Luminosity Evolution of Early-Type Galaxies . In: The Astronomical Journal . 122, No. 3, 2001, pp. 1084-1103. arxiv : astro-ph / 0106566 . bibcode : 2001AJ .... 122.1084L . doi : 10.1086 / 322134 .
  10. ↑ Hathi, NP; Malhotra, S .; Rhoads, JE: Starburst Intensity Limit of Galaxies at z ~ = 5-6 . In: The Astrophysical Journal . 673, No. 2, 2007, pp. 686-693. arxiv : 0709.0520 . bibcode : 2008ApJ ... 673..686H . doi : 10.1086 / 524836 .
  11. ↑ Peebles, PJE: The Standard Cosmological Model . In: M. Greco (ed.): Le Rencontres de Physique de la Valle d'Aoste 1998, arxiv : astro-ph / 9806201 , bibcode : 1998astro.ph..6201P .