1889-1953. US astronomer, who discovered the
existence of other galaxies outside our own,
and classified them according to their shape.
His theory that the universe is expanding is
now generally accepted. Born in Marshfield,
Missouri, Hubble originally studied law
before joining Yerkes Observatory 1914,
subsequently moving to Mount Wilson, where in
1923 he discovered Cepheid variable stars
outside our own Galaxy. In 1925 he introduced
the classification of galaxies as spirals,
barred spirals and ellipticals. In 1929 he
announced Hubble's law, which states that the
galaxies are moving apart at a rate that
increases with their distance.