Hubble's law
Videos
Hubble's law, officially the Hubble–Lemaître law, is the observation in physical cosmology that galaxies are moving away from Earth at speeds proportional to their distance. Thus, the farther a galaxy
Three steps to the Hubble constant
Fit of redshift velocities to Hubble's law. Various estimates for the Hubble constant exist.
A variety of possible recessional velocity vs. redshift functions including the simple linear relation v = cz; a variety of possible shapes from theories related to general relativity; and a curve that does not permit speeds faster than light in accordance with special relativity. All curves are linear at low redshifts.
Bridge diagram showing different measurements of the Hubble constant, 2021
Observations show that the expansion of the universe is accelerating, such that the velocity at which a distant galaxy recedes from the observer is continuously increasing with time. The accelerated e
Lambda-CDM, accelerated expansion of the universe. The timeline in this schematic diagram extends from the Big Bang/inflation era 13.8 billion years ago to the present cosmological time.
Artist's impression of a Type Ia supernova, as revealed by spectro-polarimetry observations
The expansion of the Universe accelerating. Time flows from bottom to top.