Life in the Universe; October 1994; Scientific American Magazine; by Weinberg; 6 Page(s)

In Walt Whitman's often quoted poem "When I Heard the Learn'd Astronomer," the poet tells how, being shown the astronomer's charts and diagrams, he became tired and sick and wandered off by himself to look up "in perfect silence at the stars." Generations of scientists have been annoyed by these lines. The sense of beauty and wonder does not become atrophied through the work of science, as Whitman implies. The night sky is as beautiful as ever, to astronomers as well as to poets. And as we understand more and more about nature, the scientist's sense of wonder has not diminished but has rather become sharper, more narrowly focused on the mysteries that still remain.

The nearby stars that Whitman could see without a telescope are now not so mysterious. Massive computer codes simulate the nuclear reactions at the stars' cores and follow the flow of energy by convection and radiation to their visible surfaces, explaining both their present appearance and how they have evolved. The observation in 1987 of gamma rays and neutrinos from the supernova in the Large Magellanic Cloud provided dramatic confirmation of the theory of stellar structure and evolution. These theories are themselves beautiful to us, and knowing why Betelgeuse is red may even add to the pleasure of looking at the winter sky.