Biography and Work of Edwin Hubble

Biography and Work of Edwin Hubble

Edwin Powell Hubble is renowned for determining that there are other

galaxies in the Universe beyond the Milky Way, and for observing that

the universe is expanding at a constant rate.

Hubble was a tall, elegant, athletic, man who at age 30 had an

undergraduate degree in astronomy and mathematics, a legal degree as a

Rhodes scholar, followed by a PhD in astronomy. He was an attorney in

Kentucky (joined its bar in 1913), and had served in WWI, rising to

the rank of major. He was bored with law and decided to go back to his

studies in astronomy.

In 1919 he began to work at Mt. Wilson Observatory in California,

where he would work for the rest of his life. He was researching

nebulae, fuzzy patches of light in the sky. In 1924, he announced the

discovery of a Cepheid, or variable star, in the Andromeda Nebulae.

Since the work of Henrietta Leavitt had made it possible to calculate

the distance to Cepheids, he calculated that this Cepheid was much

further away than anyone had thought and that therefore the nebulae

was not a gaseous cloud inside our galaxy, like so many nebulae, but

in fact, a galaxy of stars just like the Milky Way. Only much further

away. Until now, people believed that the only thing existing ouside

the Milky Way were the Magellanic Clouds. The Universe was much bigger

than had been previously presumed.

Hubble wanted to classify the galaxies according to their content,

distance, shape, and brightness patterns, and in his observations he

made another momentous discovery: By observing redshifts in the light

wavelengths emitted by the galaxies, he saw that galaxies were moving

away from each other at a rate constant to the distance between them

(Hubble's Law). The further away they were, the faster they receded.

This led to the calculation of the point where the expansion began,

and confirmation of the big bang theory. Hubble calculated it to be

about 2 billion years ago, but more recent estimates have revised that