英文杂志-Magazine：Wormholes

Wormholesby Linda BaxterHave you ever read Carl Sagan's 1985 science fiction novel 'Contact'? Or have you seen the film of the same name starring Jodie Foster¹? If you have, then you will remember the scene near the end of the film, when the heroine travels to the star Vega, twenty-six light years away from Earth, through a wormhole in space. Just a story, you think. But is it?

The truth is that the scene described above is a serious scientific picture of travel through spacetime using a wormhole. When Sagan was writing the book, he asked an American scientist, Kip Thorne, to give him an idea for a way of travelling long distances through space that was scientifically possible. Thorne thought about it for a long time and then had the idea of using a wormhole. He then looked again at Einstein's theories and the accepted rules of physics and was surprised to see that wormholes really could be used to travel through space.

But what is a wormhole?A wormhole is a passageway between points in a 'folded' universe. The easiest way is to imagine a big piece of paper, with A written at one end and B written at the other. It will take a small insect a long time to walk from A to B. But now fold the paper in half, so that A and B are near to each other. Now connect A and B with a small tube pushed through the paper - the wormhole. The distance between A and B is now only a few millimetres, and the insect can walk along the tube and make the journey in a fraction² of the time. So distances of many light years in space could become just a few metres.

So, did Kip Thorne invent wormholes?No he didn't. Kip Thorne proved that there is nothing in the laws of physics and the general relativity³ theory to say that they're not possible. Einstein talked about 'folds' in the universe. He also thought that if these folds existed, then there might be passages, or shortcuts⁴ connecting them. He thought that there might be passages like these connecting two black holes, so that something could enter one black hole, travel through the wormhole and come out again at the other end. He called them 'bridges'. But for some reason, nobody thought very much about them until the 1980s.

But isn't it impossible for anything to escape from a black hole?True. A black hole has such strong gravity that nothing, not even light, can escape from it. Everything is crushed⁵ at the centre point of the black hole. But mathematicians⁶ have proved that things are different if the hole is rotating⁷. Then, it may be possible for a doorway⁸ to open at the centre point, where the wormhole begins. And some people believe that white holes exist too. These are the opposite of black holes. Instead of holding everything inside, a white hole pushes everything out. So you could enter a rotating black hole, travel through a wormhole, and then come flying out of a white hole at the other end.

But is it really possible?Theoretically⁹, yes. But there are a few problems. Wormholes are not very stable. They only exist for a few seconds before they collapse¹⁰. And something travelling through one would probably make it break up anyway. And a wormhole would be full of x-rays and gamma rays, which would burn you. And of course, you would never be sure where you were going and almost certainly, you wouldn't be able to come back again the same way. So if we can find a natural wormhole, we then need the technology to control and stabilise it. Which is exactly what the advanced civilisation¹¹ in 'Contact' were able to do.

Could we use wormholes to travel through time?There are people who think exactly that. Einstein's equations¹² treat space and time in exactly the same way. So a wormhole can link two different times as well as two different places. According to Einstein's theories, time travel would be difficult but not impossible. Scientists now take the idea very seriously. But there are some big problems of logic¹³. For example, if you went back in time and killed your grandmother, you would then never be born. So you never existed, so you couldn't travel back in time because you didn't exist! To explain this problem (known as 'the granny paradox') people have invented theories to say that you can only travel back in time to the moment when the time machine was invented. This theory also explains why we don't have lots of 'time travel tourists' visiting us now.

So, in conclusion, wormholes have never been found in nature. No astronomer¹⁴ has ever seen things come flying out of one in the middle of space. But we do know that, according to the rules of physics that we use, they are possible. And if we could find one and control it, travel through space and maybe even time would be a real possibility.

 

1 foster   

vt.收养，培养，促进；adj.收养的，收养孩子的

参考例句：

• Nowadays young couple sometimes foster.现今年轻夫妇有时领养别人的孩子。
• The captain did his best to foster a sense of unity among the new recruits.队长尽力培养新成员之间的团结精神。

2 fraction   

n.小部分，碎片；一点，一些；分数

参考例句：

• The car missed me by a fraction of an inch.那车子差一点儿就要撞到我了。
• The cost is only a fraction of his salary.那项费用不过是他薪水的一小部分。

3 relativity   

n.爱因斯坦的相对论；相关性，相对性

参考例句：

• Finally they accepted Einstein's relativity.他们终于接受了爱因斯坦的相对论。
• There is no relativity between the two matters.这两件事毫无关系。

4 shortcuts   

n.捷径( shortcut的名词复数 )；近路；快捷办法；被切短的东西（尤指烟草）

参考例句：

• In other words, experts want shortcuts to everything. 换句话说，专家需要所有的快捷方式。 来自About Face 3交互设计精髓
• Offer shortcuts from the Help menu. 在帮助菜单中提供快捷方式。 来自About Face 3交互设计精髓

5 crushed   

a.压碎的，倒碎的

参考例句：

• The car was completely crushed under the truck. 小轿车被卡车压得完全变形了。
• The box was crushed when the car ran over it. 汽车辗过箱子时把它给压碎了。

6 mathematicians   

数学家( mathematician的名词复数 )

参考例句：

• Do you suppose our mathematicians are unequal to that? 你以为我们的数学家做不到这一点吗？ 来自英汉文学
• Mathematicians can solve problems with two variables. 数学家们可以用两个变数来解决问题。 来自哲学部分

7 rotating   

ing. 转动

参考例句：

• It can be used on rotating machinery and under water. 它可以用于回转式机器，也可以在水下应用。
• So a separate rotating aerial is used for that purpose. 为此需要用一种单独的旋转天线。

8 doorway   

n.门口，(喻)入门；门路，途径

参考例句：

• They huddled in the shop doorway to shelter from the rain.他们挤在商店门口躲雨。
• Mary suddenly appeared in the doorway.玛丽突然出现在门口。

9 theoretically   

adv.理论地，理论上

参考例句：

• It's theoretically possible, but highly unlikely ever to happen. 这从理论上说是有可能的，但是基本上不会发生。 来自《简明英汉词典》
• Theoretically, a line can extend into infinity. 从理论上来说直线可以无限地延伸。 来自《简明英汉词典》

10 collapse   

vi.累倒；昏倒；倒塌；塌陷

参考例句：

• The country's economy is on the verge of collapse.国家的经济已到了崩溃的边缘。
• The engineer made a complete diagnosis of the bridge's collapse.工程师对桥的倒塌做了一次彻底的调查分析。

11 civilisation   

n.文明，文化，开化，教化

参考例句：

• Energy and ideas are the twin bases of our civilisation.能源和思想是我们文明的两大基石。
• This opera is one of the cultural totems of Western civilisation.这部歌剧是西方文明的文化标志物之一。

12 equations   

方程式( equation的名词复数 )； 相等； 等同看待

参考例句：

• The overwhelming majority of nonlinear differential equations are not soluble analytically. 绝大多数非线性微分方程是不能用解析方法求解的。
• To derive the transformation equations, we return to Fig. 14-1. 为了求出这个变换式，我们回顾图14－1。

13 logic   

n.逻辑(学)；逻辑性

参考例句：

• What sort of logic is that?这是什么逻辑？
• I don't follow the logic of your argument.我不明白你的论点逻辑性何在。

14 astronomer   

n.天文学家

参考例句：

• A new star attracted the notice of the astronomer.新发现的一颗星引起了那位天文学家的注意。
• He is reputed to have been a good astronomer.他以一个优秀的天文学者闻名于世。