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Which of the following has been mentioned by the author as essential for a correct understanding of a culture？
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A new look at an asteroid orbiting the sun shows it could possibly smash into the Earth with tremendous force. But experts say the potential impact is still 872 years away, time enough for the speeding space rock to alter its course.
Named 1950DA, the asteroid--1 kilometer wide--is the most threatening to the Earth of all of the known large asteroids, but the odds are only adout one in 300 that it would impact the planet, researchers said. "One in 300 is pretty long odds," said Jon D. Giorgini, a scientist in Califonia. "I'm not personally going to worry about it. It is so far in the future that lots of things could change."
There are approximately 1,000 asteroids bigger than a kilometer that can pass near the Earth in their orbit of the sun. About 580 have been found and their orbits plotted. Of these, only 1950DA represents a possible threat. Scientists continue an effort to identify all the other large asteroids that pass near the Earth, and it is their great hope that they don't find any that are greater threats. If 1950DA did hit the Earth, said Giorgini, it would have planet-wide effects, setting off fires, changing the weather and perhaps creating immense tidal waves. But it would not be a planet killer like the asteroid thought to have snuffed out the dinosaure some 65 millions years ago.
Asteroid 1950DA was first discovered in 1950, but then not noted in astronomy logs again for decades. It was rediscovered in the year 2000 and in March 2001 whizzed within about 77 million miles of Earth, giving astronomers an opportunity to gather visual and radar readings. From that, the astronomers projected the orbital path 1950DA would take on its next 15 near passes of the Earth--over a period covering nearly nine centuries. For the 15th near pass, on March 16,2880, the analysis showed it was mathematically possible, though unlikely, that the asteroid could hit the Earth.
He said the highest probability is that the asteroid in 2880 will miss the Earth by about 290, 000 kilometers--a distance closer than the 370, 000-kilometer orbit of the Moon around the Earth.
Talking about asteroids, the author tells us that ______.
The weather wasn't favorble and both teams had to ______ icy rain and a strong wind during
It is hard to predict how science is going to turn out, and if it is really good science it is impossible to predict. If the things to be found are actually new, they are by definition unknown in advance. You cannot make choices in this matter. You either have science or you don't, and if you have it you are obliged to accept the surprising and disturbing pieces of informantion, along with the neat and promptly useful bits.
The only solid piece of scientific truth about which I feel totally confident is that we are profoundly ignorant about nature. Indeed, I regard this as the major discovery of the past hundred years of biology. It is, in its way, an illuminating piece of news. It would have amazed the brightest minds of the 18th century Enlightenment to be told by any of us how little we know and how bewildering seems the way ahead. It is this sudden confrontation with the depth and scope of ignorance that represents the most significant contribution of the 20th century science and the human intellect, In earlier times, we either pretended to understand how things worked or ignored the problem, or simply made up stories to fill the gaps. Now that we have begun exploring in earnest, we are getting glimpses of how huge the questions are, and how far from being answered. Be- cause of this, we are depressed. It is not so bad being ignorant if you are totally ignorant; the hard thing is knowing in some detail the reality of ignorance, the worst spots and here and there the not-so-bad spots, but no true light at the end of the tunnel nor even any tunnels that can yet be trusted but we are making a beginning and there ought to be some satisfaction. There are probably no questions we call think up that can't be answered, sooner or later, including even the matter of consciousness. To be sure, there may well be questions we can't think up, ever, and therefore limits to the reach of human intellect, but that is another matter. Within our limits, we should be able to work our way through to all our answers if we keep at it long enough, and pay attention.
According to the author, really good science ______.
Why, according to the author, can't we let all the prisoners free？
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