Why it’s taking a century to pin down the speed of the universe

The Hubble constant, a set number that connects a galaxy’s speed to its distance from Earth and tells us how fast the universe is expanding, was first described more than a hundred years ago – but astronomers have debated it ever since

​The Hubble constant, a set number that connects a galaxy’s speed to its distance from Earth and tells us how fast the universe is expanding, was first described more than a hundred years ago – but astronomers have debated it ever since The Hubble constant, a set number that connects a galaxy’s speed to its distance from Earth and tells us how fast the universe is expanding, was first described more than a hundred years ago – but astronomers have debated it ever since