9. Aging can be reversed.
衰老的过程是可逆的。

We all grow old, part of the general trend toward growing disorder. But it's only the universe as a whole that must increase in entropy, not every individual piece of it. (Otherwise it would be impossible to build a refrigerator.) Reversing the arrow of time for living organisms is a technological challenge, not a physical impossibility. And we're making progress on a few fronts: stem cells, yeast, and even mice and human muscle tissue. As one biologist told me: "You and I won't live forever. But as for our grandkids, I'm not placing any bets."
我们都会老去，这也是这世界走向无序的趋势的一部分。但必然的熵增是针对整个宇宙而言，对宇宙的个别部分而言并非必然如此（否则我们就不可能造出冰箱了）。倒转有机体的时间流逝只是一项技术挑战，从物理学角度来说并不是不可能的。并且在某些有机体上我们已经取得了一些进展：干细胞，酵母菌，甚至老鼠和人体肌肉组织。一位生物学家曾告诉我：“你我肯定不会永生，但我们的孙辈就不一定了。”