没有剑的契约只是空话，根本无法保护一个人。

Sustainability is not just a goal, it's a responsibility we owe to the future.

The human mind is capable of comprehending the universe because the universe has generated minds capable of comprehending it.

Every problem in mathematics is a puzzle waiting to be solved, and the joy is in the solving.

我们无权假设任何物理定律存在，或者即使它们至今存在，它们将来也会以类似的方式继续存在。