William Huggins Pioneer Of The New Astronomy

"If we were to go to the sun, and to bring away some portions of it and analyze them in our laboratories, we could not examine them more accurately than we can by this new mode of spectrum analysis.''

Warren De La Rue, 18611

On a fine morning in May 1851, London's first international exhibition of works of art and industry threw open its doors to the public. The Crystal Palace, a glass-walled building resembling a giant greenhouse, sprawled over 18 acres in Hyde Park. Inside, a dizzying array of manufactured goods, machines, and raw materials invited visitors to take stock of participating countries' mineral resources and innovations in design and technology. The famous Koh-i-Noor diamond, which the British East India Company had recently presented to Queen Victoria, occupied a central showcase.

Every day except Sunday for five and a half months, tens of thousands of visitors jostled each other to admire silks and velvets, musical instruments, carriages, false teeth, electroplated coffee pots and creamers, ornate wooden cabinets, and other housewares crowding the display cabinets and galleries. Working models of industrial and agricultural machines, powered by a steam engine located outside the main building, provided an overview of the industrial revolution, which by then had reached its peak. Electric telegraph instruments, various types of batteries, and exhibits on iron and steel manufacturing processes hinted at further transformations to come.

The ''Great Exhibition,'' as it was called, expressed Victorian society's intense drive to achieve scientific and industrial progress. The world it reflected — the world in which William Huggins, then in his late twenties, began his scientific career— was full of new or newly improved tools and instruments. Microscopes first drew Huggins to independent research and the philosophical societies, but he made his mark with telescopes and spectroscopes, instruments to analyze light that came into prominence in the 1860s. Beginning in the 1870s, he and his wife Margaret were among the first to apply the art of photography—publicly presented for the first time at the ''Great Exhibition'' — to astronomy and spectroscopy.

One of Huggins's most important accomplishments was to apply spectroscopy to the nebulae, extending one of William Herschel's lines of inquiry. Herschel had explored two main questions: first, what is the shape and size of our stellar system, and second, what is the nature of the nebulae, and what role does nebulous matter play in the evolution of starry systems. Recall that Herschel at first thought that all nebulae were distant aggregates of stars, some of them unresolved even with the best available telescopes. But later, after examining the ''singular phenomenon'' of the planetary nebula NGC 1514 in Taurus, Herschel changed his mind. He began speaking of ''nebulous stars, properly so-called.'' He even speculated that stars might evolve from nebular condensations.

Herschel's follower Wilhelm Struve had mainly taken him up on the first question, charting the shape and scale of our stellar system. Huggins, although he worked on a variety of astronomical topics, drew attention back to the question of the nebulae. The shift in focus during the latter half of the nineteenth century stemmed in large part from the advent of spectroscopy, which promised unprecedented insight into the nature of nebulae. Indeed, by allowing astronomers to gauge the chemical and physical constitution of stars and nebulae, spectroscopy transformed astronomy into ''astrophysics.'' Huggins's career coincided with an era during which, for the first time, astronomers could fully appreciate the great variety of stars and nebulae, and categorize them according to their chemical and physical characteristics. In the excitement of such ''spectrum analysis,'' the measurement of parallax and other work on the scale of the galaxy temporarily lost some of its urgency.

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