A starry, starry knight

Hubble is probably the best known astronomical name of the present century, especially after the bus-sized, orbiting space telescope was named after this American astronomer. But his astronomical notoriety was mainly due to luck. He was simply the right person in the right place at the right time. And there was very little he did that could not, and would not, have been done by others during the 1920s.

Edwin Powell Hubble, the subject of this most readable and richly detailed biography by Gale E. Christianson, was born in 1889, of lower middle-class parents in Marshfield, Missouri. His father held various positions with a succession of insurance companies and in his high-school years Edwin found himself living in Wheaton, Illinois. From there the athletic, handsome, young man won a scholarship to the University of Chicago where he took a science and technology course, but also hedged his bets, and comforted his father somewhat, by preparing for the law too. At Chicago, Hubble was taught a little astronomy by the famous cosmogonist Forest Ray Moulton and some physics by the even more famous Albert Abraham Michelson and Robert Andrew Millikan. Hubble's major achievement was winning the 1910 Rhodes Scholarship from Illinois, and he left America to study jurisprudence at Queen's College, Oxford, in 1910.

This ancient university had an indelible effect on the young American. Not only did he leave with a social polish and a half blue for athletics, but he also found himself converted into an incurable anglophile. His acquired English accent, penchant for Harris tweed jackets, a cane and straight Dunhill briar pipes stayed with him for the rest of his life.

In August 1914 Hubble joined the Yerkes Observatory to study for a doctorate. There he acquired his skills as both an observer and photographer of faint nebulae. On finishing his dissertation in 1917, and being judged magna cum laude in the viva, Hubble joined the westward migration of astronomers and obtained a post at the Mount Wilson Observatory in Southern California, where he stayed for the rest of his life.

The timing was opportune because the largest telescope in the world, the 100-inch Hooker reflector, was just being commissioned; it was ready for use on September 11 1919. The telescope was the greatest gift any astronomer could desire, and Hubble never looked back. Milton Humason, an observatory night assistant writes of Hubble at the telescope "standing while he did his guiding. His tall, vigorous figure, pipe in mouth, was clearly outlined against the sky. A brisk wind whipped his military trench coat around his body and occasionally blew sparks from his pipe into the darkness of the dome ... He was sure of himself - of what he wanted to do, and of how to do it."

Hubble spent his scientific life observing and photographing extragalactic nebulae, though he never called them galaxies. He also followed in the footsteps of the famous Lowell observer Vesto Melvin Slipher and measured the red shift of the nebula light. Hubble, however, did not stress the strong link between red shift and recession velocity. In fact he always cautiously referred to the latter as theJ"apparent" velocity.

Hubble's skill, patience and dedication made him the greatest observational astronomer of the century. Good photographic images and accurate estimations of the red shift were his goal. Hubble confirmed that red shift increased linearly with distance, the ratio between these quantities becoming known as the Hubble Constant. But he revelled in knowing little astrophysics, and theory did not interest him. So he did not speculate on the implications of his "constant" in the study of the age of the universe or the creation event (or big bang as it became known). The realm of cosmological models was a quagmire he avoided at all costs.

His scientific life was a quest for the big picture. All his projects were conservative and long term. His achievements are fourfold. He overthrew the view that the Milky Way was the only galaxy in the universe by confirming the existence of a multitude of other galaxies. His red-shift work determined that the universe was expanding in an orderly fashion. He produced a superb photographic catalogue of extra-galactic nebulae. He classified the nebulae in such an elegant way that his work formed the foundation stone of galactic origin, interrelation, rotation and evolution studies. And finally he showed that the universe was isotropic, being the same in all directions as far as the biggest telescopes on earth could see.

Christianson, a history professor at Indiana State University, concentrates on Hubble the man as opposed to Hubble the astronomer, and the story of how this rather diffident, dreamy and somewhat arrogant student metamorphosed into one of the linchpins of Hollywood society in the 1930s and 1940s is absolutely fascinating. The Hubbles were friendly with Charlie Chaplin, the Marx brothers, Anita Loos, Aldous and Maria Huxley, Walt Disney and William Randolph Hearst. Albert Einstein and Fred Hoyle were also frequent visitors.

The book is superbly referenced and it is clear Christianson greatly enjoyed sifting through the mass of Hubble papers at the Henry E. Huntington Library in San Marino, California, a short step from where Hubble and his witty, rich and supportive wife, Grace Burke, lived. (Apparently Grace never met any of Hubble's family, Edwin regarding them as being too "common".) Astronomically Hubble was very much a one-subject, one-technique man, who seemingly spent his whole life painstakingly extending his doctoral thesis using ever-larger telescopes with their greater light gathering power and better resolution. Even though the Hale 200-inch telescope was built so that Hubble could double the distance at which he was looking, it is clear there is little that Hubble did that would not have been done by other astronomers given the same tools. One cannot help feeling that the modern cut and thrust of multiwavelength ground-based and space astronomy with its concomitant theoretical spur might have somewhat left him standing. But, then again, it is a happy man who has made discoveries that have not been eclipsed, and Hubble's are as fresh today as they ever were.

David Hughes is reader in astronomy, University of Sheffield.