制造链式反应机器的基本点当然是确保每次裂变产生一定数量的中子，其中一些中子再次有效地产生裂变。

Life consists not in holding good cards，but in playing well those you hold.

"A good book should leave you... slightly exhausted at the end. You live several lives while reading it."

挑战在于使不可见的东西变得可见。