by Traci Watson

        Ever since its birth, the universe has been expanding steadily outward like a balloon being inflated. Astronomers have tried for several decades to learn the rate of the expansion, which would tell them the age of the cosmos and even help them predict the fate of the universe. Last week, a long-awaited study relying on the high-tech Hubble Space Telescope to help measure the expansion rate was published in the science journal Nature. The new results won't settle the dispute over the rate, also known as the Hubble constant. But the findings do provide strong ammunition for scientists claiming the Hubble constant is high. And a high constant means the universe is relatively young -- only 8 billion to 12 billion years old. 

        The problem is, the oldest stars in the universe are some 16 billion years old. So why the discrepancy? Perhaps last week's result is in error -- but a growing body of other evidence supports the new findings. Or maybe scientists are incorrect about the age of the oldest stars. Or some basic physics might be wrong: Scientists usually assume that the cosmological vacuum -- the vast reaches of the universe that contain no matter -- exerts no force. But the vacuum may actually accelerate the expansion of space, forcing physicists to redo the calculations of the universe's age. To some physicists, though, a powerful vacuum is heresy. 

        If bolstered by future data, the new value of the Hubble constant could help determine the future of the universe. Scientists have long wondered whether the cosmos will eventually collapse on itself in a "big crunch." If the new result is right, physicists' equations tell them that the universe instead may just expand forever.