frequency of radiation from receding star is smaler than actual.Does it mean energy of its photon is lost?

Answer 1

The energy of a photon is given by E = h*c / lambda, where h is Planck's constant (6.6262^ minus 27), c is speed of light, and lambda is wavelength. (wavelength and frequency are inversely proportional)

The cosmological redshift indicates that the frequency of a photon decreases as it travels over cosmological distances in the universe, thus its energy decreases.

Answer 2

In addition to the doppler effect, I find it completely reasonable that after travelling for billions of years a photon has the right to have its frequency redden a little out of sheer tiredness. (and, if you must, you can say it tosses out neutrinos or something to account for the loss of energy)

Hence Hubble was wrong, the universe is NOT expanding, Inflationary theory is wrong, and everything is just a whole lot simpler. Further away things are redder NOT because of expansion causing doppler red-shift, but because the light is just that much older.

Don't get me wrong. Doppler effect is real. But why do we expect photons to hold their energy forever anyway? Everything else in nature runs down, why not light?

Answer 3

http://hyperphysics.phy-astr.gsu.edu/hbase/astro/transp.html
http://imagine.gsfc.nasa.gov/docs/dict_jp.html
http://www.airynothing.com/high_energy_tutorial/glossary.html
http://www.aas.org/publications/baas/v32n2/aas196/45.htm

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