Fancy a trip down a wormhole? Calculations suggest that this might be possible, because these entrances through space-time could stick around forever.
Wormholes are essentially a pair of connected black holes. Two types could theoretically exist. A non-traversable wormhole is like a room with two doors that can be used only from the outside—the doors are black holes through which things can enter, but never escape. “These are not very interesting, as any astronaut who is brave enough to venture in won’t be able to make it back to tell the story,” says Diandian Wang at the University of California.
Traversable(能横过的) wormholes are also possible, but until now we didn’t know whether they could exist for long enough for anything to pass through them. For such a wormhole to form, space-time needs to naturally change shape. In classical physics, this can’t happen. But the rules of quantum mechanics(量子力学) allow space-time to do so for brief periods.
Wang worked on a scenario(设想) involving string theory, in which the fundamental ingredient of reality is tiny strings. If one of these strings breaks, it can create a traversable wormhole with black hole-like entrances either end that allow both entry and exit.
Although researchers had shown that this was a possibility before, it seemed that the energy involved would always break the wormhole.
Now, Wang and his team have calculated that the curvature of space-time could counteract this acceleration, keeping the fake black holes still and allowing the throat of the wormhole to remain open. This scenario is extremely unlikely, and becomes even more unlikely, the longer the wormhole is and the larger the black holes are. Thanks to quantum mechanics, though, the probability of it happening isn’t zero. Wang’s team also calculated that, once a traversable wormhole exists, it could remain stable for at least as long as the universe has been around.
“The work shows how wormholes could be created from scratch,” says Aron Wall at the University of Cambridge. But he points out that they couldn’t be used to time travel or move faster than light.
1.What are wormholes in the text?
A.Real worm holes on the earth. B.Tunnels through space and time.
C.Rooms with two doors. D.A pair of strings.
2.What does “this” refer to in Paragraph 5?
A.The wormhole. B.The black hole.
C.The scenario. D.The calculation.
3.Which theory supports Wang’s scenario?
A.String theory. B.Quantum mechanics.
C.Classical physics. D.Modern research.
4.What is the best title for the text?
A.Wormholes: A New Possibility for Human Being
B.It Is Possible for People to Go Back
C.How Amazing It Is to Travel in Space
D.A New Space-time Study Is Going on
高三英语阅读理解中等难度题
Fancy a trip down a wormhole? Calculations suggest that this might be possible, because these entrances through space-time could stick around forever.
Wormholes are essentially a pair of connected black holes. Two types could theoretically exist. A non-traversable wormhole is like a room with two doors that can be used only from the outside—the doors are black holes through which things can enter, but never escape. “These are not very interesting, as any astronaut who is brave enough to venture in won’t be able to make it back to tell the story,” says Diandian Wang at the University of California.
Traversable(能横过的) wormholes are also possible, but until now we didn’t know whether they could exist for long enough for anything to pass through them. For such a wormhole to form, space-time needs to naturally change shape. In classical physics, this can’t happen. But the rules of quantum mechanics(量子力学) allow space-time to do so for brief periods.
Wang worked on a scenario(设想) involving string theory, in which the fundamental ingredient of reality is tiny strings. If one of these strings breaks, it can create a traversable wormhole with black hole-like entrances either end that allow both entry and exit.
Although researchers had shown that this was a possibility before, it seemed that the energy involved would always break the wormhole.
Now, Wang and his team have calculated that the curvature of space-time could counteract this acceleration, keeping the fake black holes still and allowing the throat of the wormhole to remain open. This scenario is extremely unlikely, and becomes even more unlikely, the longer the wormhole is and the larger the black holes are. Thanks to quantum mechanics, though, the probability of it happening isn’t zero. Wang’s team also calculated that, once a traversable wormhole exists, it could remain stable for at least as long as the universe has been around.
“The work shows how wormholes could be created from scratch,” says Aron Wall at the University of Cambridge. But he points out that they couldn’t be used to time travel or move faster than light.
1.What are wormholes in the text?
A.Real worm holes on the earth. B.Tunnels through space and time.
C.Rooms with two doors. D.A pair of strings.
2.What does “this” refer to in Paragraph 5?
A.The wormhole. B.The black hole.
C.The scenario. D.The calculation.
3.Which theory supports Wang’s scenario?
A.String theory. B.Quantum mechanics.
C.Classical physics. D.Modern research.
4.What is the best title for the text?
A.Wormholes: A New Possibility for Human Being
B.It Is Possible for People to Go Back
C.How Amazing It Is to Travel in Space
D.A New Space-time Study Is Going on
高三英语阅读理解中等难度题查看答案及解析
– Fancy seeing you here at this time!
-- ____
A. It's a small world. B. That’s all right.
C. Oh, I never thought. D. Oh, haven’t you?
高三英语单项填空中等难度题查看答案及解析
Many students will take part in the school sports meeting this week, so she suggested that the class meeting _______ held on Saturday .
| A．not be | B．not to be | C．be not | D．be not to |
高三英语单项填空简单题查看答案及解析
Research ______________ out at Liverpool University supports this idea and suggests that if we don’t use the sense of direction, we lose it.
| A．not carry | B．carrying | C．being carried | D．having carried |
高三英语单项填空中等难度题查看答案及解析
I sincerely suggest that you try your best to finish this project，unless you don’t ________the complaints from all directions.
A．care about B．set about
C．bring about D．go about
高三英语单项填空中等难度题查看答案及解析
My mom suggests that we ________ eat out for a change this weekend. (2013·陕西，12)
A．should B．might
C．could D．would
高三英语单项填空中等难度题查看答案及解析
(2013·高考陕西卷)My mom suggests that we________eat out for a change this weekend.
A．should B．might
C．could D．would
高三英语单项填空中等难度题查看答案及解析
I would appreciate ______ very much if you could give me some suggestions.
A． this B． it C． that D． you
高三英语单项填空简单题查看答案及解析
(2013·陕西，12)My mom suggests that we ________ eat out for a change this weekend.
A．should B．might C．could D．would
高三英语单项填空中等难度题查看答案及解析
I am________your suggestion that we should spend more time on this project.
A．in memory of B．in honour of
C．in favour of D．in need of
高三英语单项填空中等难度题查看答案及解析