Hubble's constant

American  

noun

Astronomy.

1. the ratio of the recessional velocity of galaxies to their distance from the sun, with current measurements of its value ranging from 50 to 100 kilometers per second per megaparsec.

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Etymology

Origin of Hubble's constant

First recorded in 1950–55; after E. P. Hubble

Example Sentences

The universe is still expanding, at a rate of 73 kilometers per second per megaparsec, a metric known as Hubble's constant.

From Salon • Feb. 2, 2023

Hubble’s constant – proposed by Edwin Hubble in the 1920s – reveals by how much.

From The Guardian • May 10, 2018

First, we must reliably establish Hubble’s constant by measuring both the distance and the velocity of many galaxies in many directions to be sure Hubble’s law is truly a universal property of galaxies.

From Textbooks • Oct. 13, 2016

Lemaître also used data from others to derive the constant governing the expansion, known today has Hubble's constant.

From Scientific American • Jun. 27, 2011

Measured by Hubble's constant, which translates speed into distance, 3C-147 is about 4 billion light-years away from the earth.

From Time Magazine Archive