When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Redshift - Wikipedia

    en.wikipedia.org/wiki/Redshift

    To determine the redshift, one searches for features in the spectrum such as absorption lines, emission lines, or other variations in light intensity. If found, these features can be compared with known features in the spectrum of various chemical compounds found in experiments where that compound is located on Earth.

  3. Tired light - Wikipedia

    en.wikipedia.org/wiki/Tired_light

    Tired light was an idea that came about due to the observation made by Edwin Hubble that distant galaxies have redshifts proportional to their distance.Redshift is a shift in the spectrum of the emitted electromagnetic radiation from an object toward lower energies and frequencies, associated with the phenomenon of the Doppler effect.

  4. K correction - Wikipedia

    en.wikipedia.org/wiki/K_correction

    I.E. the adjustment to the standard relationship between absolute and apparent magnitude required to correct for the redshift effect. [4] Here, D L is the luminosity distance measured in parsecs . The exact nature of the calculation that needs to be applied in order to perform a K correction depends upon the type of filter used to make the ...

  5. Hubble's law - Wikipedia

    en.wikipedia.org/wiki/Hubble's_law

    The redshift z is often described as a redshift velocity, which is the recessional velocity that would produce the same redshift if it were caused by a linear Doppler effect (which, however, is not the case, as the velocities involved are too large to use a non-relativistic formula for Doppler shift).

  6. Photometric redshift - Wikipedia

    en.wikipedia.org/wiki/Photometric_redshift

    A photometric redshift is an estimate for the recession velocity of an astronomical object such as a galaxy or quasar, made without measuring its spectrum.The technique uses photometry (that is, the brightness of the object viewed through various standard filters, each of which lets through a relatively broad passband of colours, such as red light, green light, or blue light) to determine the ...

  7. Photobiology - Wikipedia

    en.wikipedia.org/wiki/Photobiology

    Photobiology is the scientific study of the beneficial and harmful interactions of light (technically, non-ionizing radiation) in living organisms. [1] The field includes the study of photophysics, photochemistry, photosynthesis, photomorphogenesis, visual processing, circadian rhythms, photomovement, bioluminescence, and ultraviolet radiation effects.

  8. Baryon acoustic oscillations - Wikipedia

    en.wikipedia.org/wiki/Baryon_acoustic_oscillations

    The Sloan Digital Sky Survey (SDSS) is a major multi-spectral imaging and spectroscopic redshift survey using the dedicated 2.5-metre wide-angle SDSS optical telescope at Apache Point Observatory in New Mexico. The goal of this five-year survey was to take images and spectra of millions of celestial objects. The result of compiling the SDSS ...

  9. Redshift quantization - Wikipedia

    en.wikipedia.org/wiki/Redshift_quantization

    Redshift quantization, also referred to as redshift periodicity, [1] redshift discretization, [2] preferred redshifts [3] and redshift-magnitude bands, [4] [5] is the hypothesis that the redshifts of cosmologically distant objects (in particular galaxies and quasars) tend to cluster around multiples of some particular value.