THE standard theory of the universe may have to be revised because the age it implies for the cosmos is too young, new observations from the Hubble Space Telescope suggest.
When the observations are interpreted according to standard theory, the universe is estimated to be about 9.5 billion years old. But that clashes with solid evidence that some stars are older, at least 12 billion to 17 billion years old.
One obvious solution to the conflict is to revise the standard theory, says astronomer Nial Tanvir of Cambridge University in England. He presents the new work with colleagues in yesterday's issue of the journal Nature.
The age conflict made headlines last year when another team of scientists reported their findings from the Hubble. Their observations suggested that under the standard theory, the universe would be only 8 billion years old.
Both Hubble studies were aimed at finding the most sought-after number in astronomy, the so-called Hubble constant, which is the rate at which the universe is expanding. That number, combined with assumptions about the cosmos, gives an age for the universe. In the new study, that age comes to 9.5 billion years under standard assumptions about the universe.
Tanvir says that estimate is unlikely to be right, given the calculated ages of the oldest stars. The star ages have been extensively scrutinized, and it appears they could not be lowered without resorting to fundamental changes in scientific understanding of particle physics, he said.
So the new study suggests that the standard assumptions about the cosmos might be wrong, Tanvir said.
One possibility, he said, is that the universe contains much less matter than standard theory says. The traditional idea is that the universe contains just enough matter that it will continue expanding at an ever-slowing rate, never quite coming to a halt. But by assuming instead that the universe contains only one-tenth that amount of matter, the new finding implies an age of 12.5 billion years.