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

　　Some scientists believe we should keep an open mind about time reversal. Open-minders speculate that time-travelers who change the past would be opening doors to alternative histories, rather than interfering with history as we know it. For example, if you prevented the assassination of Abraham Lincoln, then a new line of historical development would be create. The alternative history ― the one without Lincolns assassination ― would have a completely separate, ongoing existence. Thus, no change would be made in anybodys existing history. Another possibility is that nature might have an unbreakable law preventing time travelers from changing the past.

　　If we did discover a source of energy that would enable us to travel beyond lightspeed, we might have access not only to the past, but also to the future. Suppose you went on a super-lightspeed trek to the Spiral Nebula in the Andromeda Galaxy. that location is separated from Earth by 1,500,000 lightyears, the distance light travels in 1,500,000 years. Suppose you make the round trip in just a few moments. If all goes well, youll return to the Earth 3,000,000 years into its future, because thats how much Earth time will have elapsed.

　　Time is an abstraction. In other words, it cannot be seen, touched, smelled, or tasted. It seems to have no existence apart from the events it measures, but something tells us that time is out there, somewhere. When we pursue the meaning of time, according the time-obsessed English novelist-playwright J.B.Priently, We are like a knight on a quest, condemned to wander through innumerable forests, bewildered and baffled, because the magic beast he is looking for is the horse he is riding.