Science: Lens Work

The observable universe—which may comprise almost all of the total universe —is a vast sphere approximately 1,000,000,000 light-years across (one light-year equals about six trillion miles). Human knowledge of the outermost fringes of this sphere is mostly due to the work of Astronomers Edwin Powell Hubble and Milton La Salle Humason, whose long looks into space are made possible by Mt. Wilson Observatory’s 100-inch telescope. Even with this giant instrument, catching the spectra of far-off island universes has required all-night exposures for several nights.

Last week it was disclosed that Dr. Humason has put to work the world’s fastest lens, for further survey of the abysses beyond the Milky Way. Designed by Dr. Wilbur Bramley Rayton, technical chief of Bausch & Lomb Optical Co., the lens has a speed of f:0.59, six and one-half times faster than commonly used in minicameras (f:1.5). The necessary time for spectographing remote nebulae has been cut in half, in one instance from 120 hours to 60 hours. “It is now possible,” said Dr. Humason, “to observe faint objects which have heretofore seemed hopeless; one of these is a very faint cluster of nebulae in Ursa Major, probably one of the most remote clusters known. . . .”

The sun, a thoroughly commonplace star, is only eight light-minutes from earth, a fact which sufficiently explains its unique importance to mankind. Yet observation of the sun like that of other celestial bodies is impeded by the distorting effect of earth’s atmosphere. An observer at an altitude of 25,000 ft., however, has two-thirds of the effective atmosphere beneath him. To that altitude a Pan-American Grace Airliner mounted over Peru during the total eclipse of last June (TIME, June 14) and from it Major Albert W. Stevens, stratosphere balloonist, made unusual photographs of the eclipsed sun which he showed last week at Manhattan’s Hayden Planetarium, after they had been given a scientific bill of health by a conference of 50 astronomers at Harvard. The pictures showed a vast, globular corona reaching out from the sun to a depth about equal to its diameter (864,100 miles) in which the vivid coronal streamers commonly pictured formed a bright, irregular core. The globular corona had been photographed before but these swiftly-taken candid camera shots made in mid-air were its best portraits to date.