The importance of theoretical computer science lies in its ability to provide a foundation for practical applications.

效率是把事情做对；效果是做对的事情。

Around computers it is difficult to find the correct unit of time to measure progress. Some cathedrals took a century to complete. Can you imagine the grandeur and scope of a program that would take as long?

The robustness of topological states against local perturbations is a testament to the power of topology in protecting quantum information.