Hubble’s lawastronomy

Assorted References

• red shift ( in red shift )

  ...from the Milky Way system, in which the Earth is located, and that their red shifts increase proportionally with their increasing distance. This generalization became the basis for what is called Hubble’s law, which correlates the recessional velocity of a galaxy with its distance from the Earth. That is to say, the greater the red shift manifested by light emanating from such an object, the...

  in astronomy: Determining astronomical distances )

  ...the speeds with which those galaxies are receding from Earth (as determined from the Doppler shift in the wavelengths of their emitted light (see redshift). This correlation is expressed in the Hubble law: velocity = H × distance, in which H denotes Hubble’s constant, which must be determined from observations of the rate at which the galaxies are...

• spectrosocopy ( in spectroscopy: Applications )

  ...observer. During the 1920s, the American astronomer Edwin Hubble identified the diffuse elliptical and spiral objects that had been observed as galaxies. He went on to discover and measure a roughly linear relationship between the distance of these galaxies from the Earth and their Doppler shift. In any direction one looks, the farther the galaxy appears, the faster it is receding from the...

• time direction ( in nature, philosophy of: Problems at the macrophysical level )

  ...direction in time—with increasing entropy on the macroscopic level and with collision rate counts on the microscopic level—results from an expansion of the universe. Surprisingly, the Hubble expansion of the system of all the galaxies—so named after Edwin Hubble, an extragalactic astronomer—thus displays physical effects right down to the level of everyday physics;...