“What we have done wrong to get a conclusion so stupid?”. According to Australian astronomer Brian has Schmidt, this was what was asked when he discovered, to his team, which has become a finding about the universe so important, many say, nothing is the same since. It was in 1998. The finding is the dark energy of the cosmos and what Schmidt revealed, with his group, in Australia, and Saul Perlmutter with his, in the U.S., is that the expansion of the universe began with the big initial explosion, far from be slowing , as expected, is accelerating. And the best explanation of this unexpected phenomenon is dark energy. It is now known that dark energy accounts for nearly 70% of all that exists, while known matter is no more than 5% and the rest is also mysterious, though perhaps not as dark matter. So Schmidt is surprised: “70% of the universe had gone unnoticed until recently.” And the answer is possible that Albert Einstein would, with much antici pation, almost a century ago.
Australian scientist, who received the Nobel Prize in Physics in 2011, for the great discovery, along Perlmutter and Adam Riess, today imparts a talk outreach, in Madrid, in the Foundation BBVA, about dark energy.
Schmidt
research that led to the great discovery intended to measure the expansion of the universe when it was much younger than now (has 13,800 million years). The galaxies are receding from each other (and that space-time is stretched due to the large initial burst) and it was at that astronomical observation work was to measure the long expansion. The idea, he explains, was that due to the gravitational attraction of matter, the cosmos would now slowing. “The big surprise was to see the opposite, ie, that the universe was expanding more slowly in the past.” The data team competitor, Perlmutter, showed the same effect, so the two independent scientific groups presented the unexpected results and cosmologists were forced to start looking for an explanation.
“have already been proposed over 5,000 ways to explain it,” says Schmidt, but the one that best fits the observations is the so-called cosmological constant proposed by Einstein in 1917. Constant that Einstein introduced into his equations to stop the universe, since their equations gave results in a dynamic cosmos rather than static, as thought then it would be. “Keep in mind that in 1917 had not discovered the expansion of the cosmos,” says Schmidt. And that cosmological constant acts as a negative pressure that counteracts the gravitational attraction of matter, galaxies, so these are separated faster and faster. Is the accelerating expansion of the universe.
When Edwin Hubble discovered in 1929 that the galaxies are moving away from each other and when they are farther away faster, Einstein withdrew its unnecessary and braking mechanism of the universe from his equations. “The cosmological constant, which Einstein called his biggest mistake, it could be my greatest discovery,” says Schmidt.
accelerating cosmic expansion, more and more data and theoretical physicists try to explain, on the one hand, while astronomers make observations of the sky for new data to help determine whether “the biggest mistake of Einstein” turns out to be the right answer or not. Schmidt, after the Nobel deeper research in this scientific question astronomer fascinating as it is. Work at the Mount Stromlo Observatory of the Australian National University. He believes that will come to explain dark energy “within my life.” As for dark energy, that 25% of the composition of the universe and does not emit or absorb light (and therefore not seen, but its existence is seen by its gravitational effect), Schmidt believes that the answer should not walk too far.
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