The world owes all its onward impulses to men ill at ease. The happy man inevitably confines himself within ancient limits.
No one is free, even the birds are chained to the sky.
The galactic center is a unique natural experiment in strong gravity.
如果你知道如何使用它，电脑是一个奇妙的工具。
徒步旅行的真正魅力不在于行走，也不在于风景，而在于交谈。