万物简史 第31期:走进太阳系(9)
So the solar system is really quite enormous. By the time we reach Pluto, we have come so far that the Sunour dear, warm, skin-tanning, life-giving Sunhas shrunk to the size of a pinhead. It is little more than a bright star. 所以，太阳系确实是
万物简史 第32期:走进太阳系(10)
Of course we have no prospect of such a journey. A trip of 240,000 miles to the Moon still represents a very big undertaking for us. A manned mission to Mars, called for by the first President Bush in a moment of passing giddiness, was quietly droppe
万物简史 第33期:走进太阳系(11)
But let's pretend again that we have made it to the Oort cloud. The first thing you might notice is how very peaceful it is out here. We're a long way from anywhere nowso far from our own Sun that it's not even the brightest star in the sky. It is a
万物简史 第34期:走进太阳系(12)
So that's your solar system. And what else is out there, beyond the solar system? Well, nothing and a great deal, depending on how you look at it. 这就是你所在的太阳系。太阳系之外还有别的什么？哎呀，也许什么也没有，也
万物简史 第35期:走进太阳系(13)
Still, statistically the probability that there are other thinking beings out there is good. Nobody knows how many stars there are in the Milky Wayestimates range from 100 billion or so to perhaps 400 billionand the Milky Way is just one of 140 billi
万物简史 第36期:走进太阳系(14)
What an interesting and exciting thought. We may be only one of millions of advanced civilizations. Unfortunately, space being spacious, the average distance between any two of these civilizations is reckoned to be at least two hundred light-years, w
万物简史 第37期:埃文斯牧师的宇宙(1)
3 THE REVEREND EVANS'S UNIVERSE 3.埃文斯牧师的宇宙 When the skies are clear and the Moon is not too bright, the Reverend Robert Evans, a quiet and cheerful man, lugs a bulky telescope onto the back deck of his home in the Blue Mountains of Au
万物简史 第38期:埃文斯牧师的宇宙(2)
Supernovae occur when a giant star, one much bigger than our own Sun, collapses and then spectacularly explodes, releasing in an instant the energy of a hundred billion suns, burning for a time brighter than all the stars in its galaxy. It's like a t
万物简史 第39期:埃文斯牧师的宇宙(3)
Evans's is a talent so exceptional that Oliver Sacks, in An Anthropologist on Mars, devotes a passage to him in a chapter on autistic savantsquickly adding that there is no suggestion that he is autistic. Evans, who has not met Sacks, laughs at the s
万物简史 第40期:埃文斯牧师的宇宙(4)
The term supernova was coined in the 1930s by a memorably odd astrophysicist named Fritz Zwicky. Born in Bulgaria and raised in Switzerland, Zwicky came to the California Institute of Technology in the 1920s and there at once distinguished himself by
万物简史 第41期:埃文斯牧师的宇宙(5)
But Zwicky was also capable of insights of the most startling brilliance. In the early 1930s, he turned his attention to a question that had long troubled astronomers: the appearance in the sky of occasional unexplained points of light, new stars. 然而
万物简史 第42期:埃文斯牧师的宇宙(6)
On January 15, 1934, the journal Physical Review published a very concise abstract of a presentation that had been conducted by Zwicky and Baade the previous month at Stanford University. 1934年1月15日，《物理学评论》杂志刊登了一篇论
万物简史 第43期:埃文斯牧师的宇宙(7)
Interestingly, Zwicky had almost no understanding of why any of this would happen. According to Thorne, he did not understand the laws of physics well enough to be able to substantiate his ideas. Zwicky's talent was for big ideas. OthersBaade mostlyw
万物简史 第44期:埃文斯牧师的宇宙(8)
Surprisingly little of the universe is visible to us when we incline our heads to the sky. Only about 6,000 stars are visible to the naked eye from Earth, and only about 2,000 can be seen from any one spot. With binoculars the number of stars you can
万物简史 第45期:埃文斯牧师的宇宙(9)
So when a hopeful and softspoken minister got in touch to ask if they had any usable field charts for hunting supernovae, the astronomical community thought he was out of his mind. At the time Evans had a ten-inch telescopea very respectable size for
