万物简史 第16期:如何营造一个宇宙(8)
The Big Bang theory isn't about the bang itself but about what happened after the bang. Not long after, mind you. By doing a lot of math and watching carefully what goes on in particle accelerators, scientists believe they can look back to 10-43secon
万物简史 第17期:如何营造一个宇宙(9)
The eventual result was the inflation theory, which holds that a fraction of a moment after the dawn of creation, the universe underwent a sudden dramatic expansion. It inflatedin effect ran away with itself, doubling in size every 10-34seconds. The
万物简史 第18期:如何营造一个宇宙(10)
What is extraordinary from our point of view is how well it turned out for us. If the universe had formed just a tiny bit differentlyif gravity were fractionally stronger or weaker, if the expansion had proceeded just a little more slowly or swiftlyt
万物简史 第19期:如何营造一个宇宙(11)
Martin Rees, Britain's astronomer royal, believes that there are many universes, possibly an infinite number, each with different attributes, in different combinations, and that we simply live in one that combines things in the way that allows us to
万物简史 第20期:如何营造一个宇宙(12)
I should say that everything is just right so far. In the long term, gravity may turn out to be a little too strong, and one day it may halt the expansion of the universe and bring it collapsing in upon itself, till it crushes itself down into anothe
万物简史 第21期:如何营造一个宇宙(13)
The analogy that is usually given for explaining the curvature of space is to try to imagine someone from a universe of flat surfaces, who had never seen a sphere, being brought to Earth. No matter how far he roamed across the planet's surface, he wo
万物简史 第22期:如何营造一个宇宙(14)
For a long time the Big Bang theory had one gaping hole that troubled a lot of peoplenamely that it couldn't begin to explain how we got here. Although 98 percent of all the matter that exists was created with the Big Bang, that matter consisted excl
万物简史 第23期:走进太阳系(1)
2.WELCOME TO THE SOLAR SYSTEM 2.欢迎来到太阳系 Astronomers these days can do the most amazing things. If someone struck a match on the Moon, they could spot the flare. From the tiniest throbs and wobbles of distant stars they can infer the siz
万物简史 第24期:走进太阳系(2)
This was actually something of a blow to Pluto's status as a planet, which had never been terribly robust anyway. Since previously the space occupied by the moon and the space occupied by Pluto were thought to be one and the same, it meant that Pluto
万物简史 第25期:走进太阳系(3)
One nice touch about Christy's discovery was that it happened in Flagstaff, for it was there in 1930 that Pluto had been found in the first place. That seminal event in astronomy was largely to the credit of the astronomer Percival Lowell. 克里斯蒂
万物简史 第26期:走进太阳系(4)
Tombaugh had no formal training as an astronomer, but he was diligent and he was astute, and after a year's patient searching he somehow spotted Pluto, a faint point of light in a glittery firmament. 汤博没有受过成为天文学家的专门训练,
万物简史 第27期:走进太阳系(5)
As for Pluto itself, nobody is quite sure how big it is, or what it is made of, what kind of atmosphere it has, or even what it really is. A lot of astronomers believe it isn't a planet at all, but merely the largest object so far found in a zone of
万物简史 第28期:走进太阳系(6)
So if Pluto really is a planet, it is certainly an odd one. It is very tiny: just one-quarter of 1 percent as massive as Earth. If you set it down on top of the United States, it would cover not quite half the lower forty-eight states. 因此,如果冥
万物简史 第29期:走进太阳系(7)
And how far is that exactly? It's almost beyond imagining. Space, you see, is just enormousjust enormous. Let's imagine, for purposes of edification and entertainment, that we are about to go on a journey by rocketship. We won't go terribly farjust t
万物简史 第30期:走进太阳系(8)
Now the first thing you are likely to realize is that space is extremely well named and rather dismayingly uneventful. Our solar system may be the liveliest thing for trillions of miles, but all the visible stuff in itthe Sun, the planets and their m