Scientist: "time travel" can only be made to the future |
IT information network On September 13, 2013

Real time travel? This problem has plagued physicists, researchers say that time travel was impossible, or we'll kill your own grandfather.

From the United Kingdom physicist Professor bulaien·kaokesi that time travel is possible, but there is a limitation that we can only be time travel into the future, it is impossible to go back. Time travel is a lot of science fiction plot, the future of human beings through time travel back to any point in time, according to current theory, "back to" vocabulary in this time travel seems impossible, we can move into the future. Cox believes that we can build a time machine, its prototype spacecraft close to a boat at high speeds.

If we could build a spaceship in flight velocity approaching the speed of light, then that the ship's "time" slows down , within the framework of the theory of relativity, for thousands of years in the people of the Earth may have been, but the astronauts aboard experienced only a few hours, apparently running close to the speed of the spacecraft into a time machine. In general relativity, we can time-travel, Cox believes that exists in the universe is called "wormhole" tunnel, is a convenient channel for space and time travel.

But most physicists doubt, we don't even know how to keep the wormhole open State, let alone a spaceship enter the wormhole to time travel. In Einstein's theory of relativity equation allowed wormhole channel holding time is very short, and its size is very small , and create a wormhole story seems only likely to appear in science fiction. Studies have shown that involved created the wormhole needs exotic matter, which helps maintain a wormhole opening.

(科学家：“时间旅行”只能向未来进行 | IT资讯网
2013年09月13日

时间旅行是否真实可行？这个问题一直困扰着物理学家们，有研究人员称时间旅行不可能存在，不然我们会亲手杀死自己的祖父。

来自英国物理学家布赖恩·考克斯教授认为时间旅行是可能的，但是有一个限制条件，即我们只能向未来进行时间旅行，不可能回到过去。时间旅行是许多科幻小说中的情节，未来的人类通过时间旅行回到任一个时间点上，根据现有的理论，“回到”这一词汇在时间旅行上似乎不可能实现，我们只能进入未来。考克斯教授认为我们可以打造一台时间机器，其原型差不多接近一艘可以高速运行的宇宙飞船。

如果我们可以建造一艘飞行速度接近光速的宇宙飞船，那么这艘飞船上的“时间”就会变慢，在相对论框架中，地球上的人们可能已经历了千百年，但是飞船上的宇航员只经历了几个小时，显然接近光速运行的宇宙飞船将成为一台时间机器。在广义相对论中，我们可以实现时间旅行，考克斯教授认为宇宙中存在的一种被称为“虫洞”的隧道，是进行空间和时间旅行的便捷通道。

但是大多数物理学家对此表示怀疑，我们甚至不知道如何让虫洞维持开放的状态，更不用说让宇宙飞船进入虫洞进行时空旅行。爱因斯坦相对论方程中允许的虫洞通道维持时间很短，而且其规模都非常小，创建虫洞的情景似乎只可能在科幻小说中出现。有研究显示，虫洞的创建需要一些奇异物质的介入，其有助于维持虫洞的开放。

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