Poor is the man whose pleasures depend on the permission of another.

膨胀是使宇宙变得平坦、均匀和各向同性的机制。

"The most exciting phrase to hear in science, the one that heralds new discoveries, is not 'Eureka!' but 'That's funny...'"

The security dilemma is a fundamental feature of international politics, as states' efforts to increase their own security often decrease the security of others.