Greene takes the reader to the leading edge of thinking in some of the most exciting areas of theoretical physics. And, importantly, he does not try to blind the reader with whiz-bang declarations or to mislead by giving only one perspective on topics that are highly controversial. Greene explains, in plain English, why scientists are considering some pretty far-out sounding possibilities (other universes!), how these ideas might be tested, and why other scientists are fully opposed to such investigations. Greene makes his perspective clear (that some, not all, of these ideas can fall within the heart of science but that only experimental evidence can really make the case) while giving the reader ample room to come to his or her own conclusions.
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Sucker haha~
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可以证明,空间的曲率能够转化成唯一的可观测量:空间中的物质密度(更准确地说,是物质和能量的密度)。如果物质特别多,引力就会导致空间朝自己弯曲,形成球形。如果物质很少,空间就弯曲自如,形成薯片的样子。如果物质的含量刚刚好,空间的曲率就等于零。
如果一个人,从降生起直到老死,终生都没有走出过家门,这无疑是十分悲惨的人生。而我们如果在短暂的人生中匆忙而过,对超出我们视觉的宏大和微小的世界毫无了解,每天的思想都在生活和工作的范围内徘徊,那就等于在精神上一辈子没走出过家门,这无疑是人生的一大遗憾。
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