在这篇文章里，我用自己最心仪的科学理论来开篇，又用自己最钟爱的未解之谜来结尾。抱歉我没有循规蹈矩，但所有睿智的解释皆如此。解释得越好，随之而来的问题就越多。

I began telling you what my favorite explanation is, and I ended up telling you what my favorite unsolved problem is. I apologize for not following the instructions. But that’s the way of all good explanations. The better they are, the more questions they raise.

——李奥纳特·苏士侃（Leonard Susskind）