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Hubble constant comparison table

Subject	is an instance of	has unit	has rate of change	is a kind of	has symbol	has value	has definition
astronomical constant				constant
Hubble constant	astronomical constant	km/s/Mpc	non-zero because gravity is slowing down the rate of expansion of the universe		H0	75 km/s/Mpc	The rate of expansion of the universe. The Hubble constant is equal to the recessional speed of a distant galaxy, divided by its distance from us. Assuming a homogeneous and isotropic universe, the recessional speed of a distant galaxy is proportional to its distance; thus the Hubble constant as determined by any receding galaxy should be the same, yielding a universal rate of expansion of the universe. According to estimates, the current value of the Hubble constant is approximately 100 km/s/Mpc, meaning that the distance between any two distant galaxies will double in about 10 billion years at the current rate of expansion.

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