The man behind the telescope

The Hubble Space Telescope was deployed from space shuttle Discovery on 24 April 1990 as a joint project between NASA and the European Space Agency. 

It was named after Edwin Powell Hubble, a brilliant scientist and colourful character who NASA describes as “one of the leading astronomers of the twentieth century” – but whose career in astronomy very nearly didn’t get off the ground.

Hubble was born in Marshfield, Missouri, in 1889 and grew up in a suburb of Chicago. Although a gifted student, in school he enjoyed more recognition as an athlete.

An often repeated story has it that at his high school graduation in 1906, the school principal said “‘Edwin Hubble, I have watched you for four years and I have never seen you study for 10 minutes” – then handed him a scholarship to the University of Chicago.

Studying mathematics and astronomy, he completed a science degree in 1910 before his scholastic and athletic achievements helped him become a Rhodes Scholar at Queen’s College, Oxford. Despite his interest in astronomy, he honoured a promise to his father and studied law.

He returned to the US in 1913, but rather than practise law he found work teaching at a high school in Indiana.

The lure of science proved too strong, however, and he returned to the University of Chicago, studying astronomy and receiving his PhD in 1917.

While still finishing his doctorate, Hubble was offered a position at the prestigious Mount Wilson Observatory, in Pasadena, California, but he chose to join the army instead, reportedly sending a telegraph to the observatory’s founder, George Ellery Hale, saying “Regret cannot accept your invitation. Am off to the war”.

Returning from France at the end of World War I, he did make his way to Mount Wilson, which at the time, the European Space Agency says, “was the centre of observational work underpinning the new astrophysics, later called cosmology”. The Hooker telescope, then the most powerful on Earth, had just been completed and installed after nearly a decade of work.

As NASA explains in its biography, most of Hubble’s contemporaries believed “all the universe – the planets, the stars seen with the naked eye and with powerful telescopes, and fuzzy objects called nebulae – was contained within the Milky Way galaxy. Our galaxy, it was thought, was synonymous with the universe.

“In 1923 Hubble trained the Hooker telescope on a hazy patch of sky called the Andromeda Nebula. He found that it contained stars just like the ones in our galaxy, only dimmer. One star he saw was a Cepheid variable, a type small image of the Andromeda galaxy of star with a known, varying brightness that can be used to measure distances. 

“From this Hubble deduced that the Andromeda Nebula was not a nearby star cluster but rather an entire other galaxy, now called the Andromeda galaxy.”

Hubble continued to make similar discoveries and, by the end of the 1920s, NASA says, “most astronomers were convinced that our Milky Way galaxy was but one of millions in the universe. This was a shift in thought as profound as understanding the world was round and that it revolved around the sun.”

But what NASA calls his “most astonishing discovery” resulted from his study of the spectra of 46 galaxies, “and in particular of the Doppler velocities of those galaxies relative to our own Milky Way galaxy”. 

In what became known as the Hubble Law – which, as Cosmos explains, “describes the way in which galaxies move away from each other and is fundamental, when viewed in reverse, to the theory of the Big Bang” – Hubble found that the farther apart galaxies are from each other, the faster they move away from each other. 

Based on this observation, he concluded that the universe expands uniformly. 

Several scientists had also posed this theory, based on Einstein’s Theory of General Relativity, but Hubble’s data, published in 1929, helped convince the scientific community.

In 2018 it was acknowledged that his work in this regard expanded upon calculations made by Belgian physicist George Lemaitre, published in 1927, and the work was renamed the Hubble-Lemaitre Law.

Hubble died in California on 28 September 1953.