redshifts
Light from retreating
Redshifts is the plural of redshift, the phenomenon where light from an object moving away from the observer stretches to longer wavelengths, shifting toward the red end of the spectrum.
Astronomers measure redshifts to determine how fast galaxies are receding: The redshifts of distant galaxies provide evidence for the expanding universe.
As a verb, redshifts means undergoes this shift: Light from the quasar redshifts as it travels toward Earth.
Gravitationally bound stellar assemblies
- universeComplete system or domain
- expansionIncrease in scope
- HubbleRenowned astronomer's surname
- recessionProlonged economic decline
distant · quasars · cosmology · Big Bang · light-years · cosmic · velocity · spectra
How observers differ
- EinsteinByword for genius
- massiveExtremely large and heavy
- black holesRegions of inescapable gravity
- gravityMutual mass attraction
spacetime · curvature · dilation · photon · escape · potential · general relativity · time dilation
Spatial repetition interval
- absorptionProcess of taking in
- emissionDischarged substance or act
- spectrumContinuous range of values
- linesStrokes connecting two points
photons · light · frequency · blue · electromagnetic · spectral · measurement · observation
Motion-caused frequency change
- recessionProlonged economic decline
- motionChange in position
- approachingComing toward something
- recedingMoving away from observer
measurement · radial · speed · astronomical · stellar · objects · blueshift · relative
galaxies
Gravitationally bound stellar assemblies
recession · distant · quasars · cosmology · Big Bang · light-years · cosmic · velocity · spectra · astronomy
relativity
How observers differ
- EinsteinByword for genius
- massiveExtremely large and heavy
- black holesRegions of inescapable gravity
gravity · spacetime · curvature · dilation · photon · escape · potential · general relativity · time dilation · event horizon
wavelength
Spatial repetition interval
- absorptionProcess of taking in
- emissionDischarged substance or act
- spectrumContinuous range of values
lines · photons · light · frequency · blue · electromagnetic · spectral · measurement · observation · detector
Doppler
Motion-caused frequency change
- recessionProlonged economic decline
- motionChange in position
- approachingComing toward something
receding · measurement · radial · speed · astronomical · stellar · objects · blueshift · relative · kinematics