Deflating NASA's Universe

The announcement was truly cosmic. After examining data transmitted from OAO-II, its second Orbiting Astronomical Observatory--which is still functioning effectively after a year in space --NASA this month declared that "astronomers are contemplating the possibility that the universe may be several times larger than previously believed." And how large is that? Some 40 billion lightyears* in diameter, concluded newsmen after talking to NASA. Breathlessly they reported that the most distant galaxies might be twice and even four times as far away as anyone had expected.

NASA's assumption was based on OAO-II's report of unexpectedly powerful ultraviolet radiation from half a dozen nearby galaxies. If this is true, NASA scientists reasoned, distant galaxies probably give off large amounts of the same invisible radiation. But those galaxies are receding from the earth (because of the expansion of the universe) at speeds that would cause ultraviolet light to shift toward the red end of the spectrum into visible frequencies. So the NASA men assumed the visible light from distant galaxies is intrinsically brighter than previously believed; therefore those galaxies must be farther away. "We thought we were looking at a dim light bulb close to us," a NASA scientist explained. "But now that we know that the bulb is brighter, we figure it must be more distant."

Pure Chauvinism. Last week leading cosmologists caustically deflated NASA's universe. "I don't believe a word of it," snapped Caltech's Maarten Schmidt, who in 1963 identified quasars as the most distant objects ever seen by man. "A bunch of nonsense," said Mount Palomar Astronomer Allan Sandage. "It's pure chauvinism." Astrophysicist A. G. W. Cameron of NASA's own Goddard Institute for Space Studies was equally blunt: "This strikes me as a complete misunderstanding."

In the first place, NASA's critics pointed out, ultraviolet radiation accounts for no more than a tenth of thz radiation from a galaxy. Thus, even a large increase in this component would not greatly affect a galaxy's overall brightness. Besides, modern astronomers always compensate for the "red shift" of light when viewing distant galaxies and quasars.

There are other compelling objections to NASA's announcement. Most modern astronomers are confident that the technical yardstick by which they measure distant galaxies and quasars--the red shift of light from those bodies--is reasonably accurate. And by that measure, the most distant quasar so far observed by astronomers is about 8 billion light-years away. Furthermore, in the complex Einsteinian geometry of space, diameter is a naive measurement; normal concepts of shape are meaningless. Astronomers were also nettled by the way that NASA released its information. Ignoring the scientific community, the space agency has to date published its conclusions only in a press release that was issued on the first anniversary of OAO-II's launch. "Remember," said Caltech's Jess Greenstein, "you're studying a public relations report, not a scientific paper."

Galactic Structure. NASA's apparent error in cosmological calculations in no way detracts from the splendid performance of the Orbiting Astronomical Observatory. Operating in a 480-mile-high orbit above the polluted obscuring atmosphere and equipped with 11 telescopes, it has given astronomers a view of the skies unattainable on earth. In addition to its ultraviolet readings--which will almost surely contribute to knowledge about galactic structure--OAO II has discovered that young, "hot" stars are losing far more of their matter in the process of maturation than had hitherto been thought: as much as the mass of the earth in a single year. Data from the orbiting astronomical satellite has also confirmed the presence of graphite crystals in the intergalactic dust beyond the Milky Way. Both phenomena should help scientists understand better how stars and galaxies evolve. With any luck, scientists believe, OAO-II could continue to probe the secrets of the universe for many more months.

*A light-year is the distance traveled by light in one year --about 6 trillion miles.

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