题目内容
But much of the wobble has been fixed, thanks to a satellite known as the Wilkinson Microwave Anisotropy Probe, or WMAP. Since July 2001, WMAP has been orbiting in deep space, more than a million kilometers from Earth, studying the most ancient light in existence. And in a dramatic reminder that important space science is almost always done by machines, not fragile humans, it reported a series of precision measurements that will finally put cosmology on a firm foundation.
What the satellite found, says Princeton University's David Spergel, a theorist on the WMAP team, "is that the universe can be explained with five numbers." First, the cosmos is 13.7 billion years old, give or take a negligible couple of hundred million years. Second, the first stars turned on just 200 million years after the Big Bang. Finally, the universe is made of three things in the following proportions:4% ordinary atoms; 23% Jo "dark matter," whose nature is still unknown; and 73% "dark energy," the equally mysterious force whose antigravity effect is speeding up the cosmic expansion. "This," says astrophysicist John Bahcall, of the Institute for Advanced Study in Princeton, New Jersey, "is a rite of passage for cosmology, from speculation to precision science."
WMAP learned this and more by scrutinizing the faint whisper of microwaves left over from the Big Bang. Hidden in that radiation are patterns of warmer and cooler spots, marking places where matter was a little more or less dense than average spots that would eventually evolve into the clusters of galaxies and empty spaces that we see today. These patterns were first detected in crude form. by the Cosmic Background Explorer satellite in 1992, but without enough detail for much to be said about them.
But with a resolution some 40 times as sharp as COBE's, WMAP has plenty to say. "It’s a lot like matching fingerprints," says Spergel. "We ran computer simulations based on many different values for all of the numbers, generated patterns for each and found the one that best matched what we actually saw."
WMAP also confirmed what earlier experiments had suggested about a basic characteristic of the universe: the geometry of space-time, in the Einsteinian sense, is flat. That's consistent with a theory called inflation, which posits that the cosmos underwent a period of turbocharged expansion before it was a second old. "I have to admit," says Bahcall, "that I was skeptical of the picture theorists had put together. Inflation, dark matter, dark energy—it's all pretty implausible. But this implausible, crazy universe has now been confirmed with exquisite detail."
That's not to say that WMAP has answered every question. Nobody knows what dark matter and dark energy are, and the theory of inflation, while strengthened, is far from proved. Beyond that, there are some strange measurements in WMAP's data that might be mere statistical flukes—or might point to some major monkey wrench that could still throw cosmology into turmoil. "We should know better after we get in more data," says Charles Bennett of the Goddard Space Flight Venter, who is the V team leader.
But cosmologists won't be sitting around waiting. "You're going to see a thousand papers based on these results," says Tegmark, who is already working on several. "It's an exciting time to be in this field."
It can be inferred from the first paragraph that cosmologists
查看答案
搜索结果不匹配？点我反馈
更多问题
听力原文： Demonstrators from all over Italy gathered in a Rome square Saturday for the Family Day rally. They listened to songs like this one whose words evoked the need for children to have both a mother and a father. Married couples with their children raised their voices to protest a proposed law that would give greater rights to unmarried couples, including gays and lesbians. This woman says the family is important because society is based on the family and it is a value for everyone, not just Christians. Lay Catholic groups and family associations organized the rally. They stressed the importance of policies that will favor the traditional family unit and family values based on marriage between a man and a woman. Thousands of supporters of the controversial bill organized a counter-rally in Rome' s famed Piazza Navona square. They said Italy would be a more civilized country if it gave fights to unmarried and gay Couples. The drawl legislation still requires parliamentary approval. Prime Minister Prodi has said lawmakers in his divided coalition are free to vote on it according to their conscience
Who gathered in a Rome square Saturday for the Family Day rally？
听力原文： Paiestinian rockets fired from the Gaza Strip crashed into the battered Israeli border town of Sderot. The Islamic militant group Hamas claimed responsibility for the attack, in which a 36-year-old Israeli man was lolled when his car took a direct hit. He was the second Israeli fatality in the past two weeks, during which time Paiestinian militants have fired more than 230 rockets at Israel. The attack brought a stern warning from Prime Minister Ehudolmert at the weekly Cabinet meeting in Jerusalem. "There is no immunity for anyone involved in terror," Mr. Olmert said, hinting that the leaders of Hamas could be targeted. "We will decide when, how and to what extent we will act," he said. Mr. Olmert spoke hours after Israel launched a fresh wave of air strikes on Hamas targets in Gaza. About 50 Palestinians, most of them militants, have been killed in the raids which began 12 days ago. Hamas says it is absurd to talk about a truce while Israeli air strikes continue. And in the wake of the deadly rocket attack, Israel' s offensive shows no sign of letting up.
According to the news, who claimed responsibility for the rocket attack？
When local education authorities decide how much a grant is, they will take the following
An old wish returned to haunt the shoemaker: that he had had a son instead of a daughter, but this blew away in the snow for Fold, if anything, was a practical man. Yet he could not help but contrast the diligence of the boy, who was a peddler's son, with Miriam's unconcern for an education. True, she was always with a book in her hand, yet when the opportunity arose for a college education, she had said no, she would rather find a job. He had begged her to go, pointing out how many fathers could not afford to send their children to college, but she said she wanted to be independent. As for education, what was it, she asked, but books, which Sobel, who diligently read the classics, would as usual advise her on. Her answer greatly grieved her father.
A figure emerged from the snow, and the door opened. At the counter the man withdrew from a wet paper bag a pair of battered shoes for repair. Who he was the shoemaker for a moment had no idea, then his heart trembled as he realized, before he had thoroughly discerned the face, that Max himself was standing there, embarrassedly explaining what he wanted done to his old shoes. Though Fold listened eagerly, he couldn't hear a word, for the opportunity that had burst upon him was deafening.
He couldn't exactly recall when the thought had occurred to him, because it was clear he had more than once considered suggesting to the boy that he go out with Miriam. But he had not dared speak, for if Max said no, how would he face him again？ Or suppose Miriam, who harped so often on independence, blew up in anger and shouted at him for his meddling？ Still, the chance was too good to let by: all it meant was an introduction. They might long ago have become friends had they happened to meet somewhere, therefore was it not his duty—an obligation—to bring them together, nothing more, a harmless connivance to replace an accidental encounter in the subway, let's say, or a mutual friend's introduction in the street？ Just let him once see and talk to her, and he would for sure be interested. As for Miriam, what possible harm for a working girl in an office, who met only loudmouthed salesmen and illiterate shipping clerks, to make the acquaintance of a fine scholarly boy？ Maybe he would awaken in her a desire to go to college; if not—the shoemaker's mind at last came to grips with the truth—let her marry an educated man and live a better life.
From the first paragraph, we get the impression that
微信支付 
支付宝支付