Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: THURSDAY, October 27, 1994 TAG: 9410280019
SECTION: NATIONAL/INTERNATIONAL PAGE: A-9 EDITION: METRO
SOURCE: Los Angeles Times
DATELINE: LENGTH: Medium
Astronomers using the Hubble Space Telescope have produced the most compelling evidence yet that the cosmos is younger than scientists had thought, calling into question the estimated age of the stars and the Big Bang theory itself.
Their calculations, made public Wednesday, are significantly more accurate and broader in scope than two other recent estimates of the age of the universe. Taken together, all three studies strongly suggest that the expanding fabric of the universe - that void between the stars and galaxies - may be considerably younger than the stars themselves.
An international team of 22 scientists, led by Pasadena, Calif., astronomer Wendy L. Freedman at the Observatories of the Carnegie Institution and Barry F. Madore at the California Institute of Technology, used NASA's orbiting telescope and a special camera designed at the Jet Propulsion Laboratory in Pasadena to determine with unprecedented accuracy just how fast the universe is expanding.
That allowed them to determine that the universe is between 8 billion and 12 billion years old. More conventional estimates, based on the age of stars and less precise measurements of intergalactic distances, range from 16 billion to 20 billion years old.
While the work has Hubble scientists celebrating, the new calculations are beginning to create a major headache for cosmologists. The Hubble study indicates a possibility that the way scientists view the universe is flawed.
Are the ages of the stars too high? Is there an unexplained force at work to accelerate matter in the cosmos? Or is the Big Bang theory itself incorrect?
``There appears to be a controversy growing here,'' said University of California, Berkeley, astronomer Alexi V. Filippenko. If the results are confirmed and refined through additional observations, ``then we will really have a dilemma,'' he said. ``It might lead to a revolution in cosmology, which would be a very, very exciting thing.
``We may have to consider some new, perhaps wild ideas. Maybe there is another force pushing the universe out or something like that. That's exciting. That's what science is all about.''
Freedman's team used the space telescope to develop the most precise yardstick yet for measuring the size, scale and age of the universe by determining the distance from Earth to a distant spiral galaxy called M100.
Through the lens of a recently refurbished Wide Field/Planetary Camera, they scanned 40,000 stars to find 20 rare pulsating Cepheid guidestars in M100, which is in the Virgo cluster. Astronomers can use the variable stars to estimate the distance from Earth to the dense stellar cloud. It is the most distant galaxy in which the Cepheid variable stars have been detected.
``The speed at which they pulsate reveals their distance,'' Freedman said. ``The trick is to find them.'' The stars are so distant and so faint that ``only Space Telescope can make these types of observations routinely.''
The measurement of the distance to M100 - 56 million light years - allowed the astronomers to calculate the velocity at which the universe is expanding, called the Hubble Constant. That expansion was first discovered by astronomer Edwin Hubble, for whom the orbiting NASA telescope is named.
In the NASA team's report, published today in the journal Nature, the researchers emphasized that they have at least three years of additional work before they can reach definitive conclusions.
by CNB