2013年6月英语四级听力SectionC外刊原文_大学英语听力

2013年6月英语四级听力SectionC外刊原文

　　Speed is not the only factor that slows time; so does gravity. Einstein determined in his General Theory of Relativity that the force of an objects gravity curves the space in the objects gravitational field. When gravity curves space, Einstein reasoned, gravity also must curve time, because space and time ar linked.

　　Numerous atomic clock experiments have confirmed Einsteins calculation that the closer you are to the Earths center of gravity, which is the Earths core, the slower you will age. In one of these experiments, an atomic clock was taken from the National Bureau of Standards in Washington, D.C., near sea level, and moved to mile-high Denver. The results demonstrated that people in Denver age more rapidly by a tiny amount than people in Washington.

　　If you would like gravitys space-time warp to extend your life, get a home at the beach and a job as a deep-sea dever. Avoid living in the mountains or working in a skyscraper. That advice, like the advice about flying around the world, will enable you to slow your aging by only a few billionths of a second. Nevertheless, those tiny fractions of a second add up to more proof that time-stretching is a reality.

　　According to scientific skeptics, time reversal ―travel to the past ―for humans would mean an unthinkable reversal of cause and effect.

　　This reversal would permit you to do something in the past that changes the present. The skeptics worry that you even might commit an act that prevents your own birth.