A college physics professor was explaining a particularly complicated concept to his class when a pre-med student interrupted him.

"Why do we have to learn this stuff?" The young man blurted out.

"To save lives," the professor responded before continuing the lecture.

A few minutes later the student spoke up again. "So how does physics save lives?"

The professor stared at the student for a long time. "Physics saves lives," he said, "because it keeps the idiots out of medical school."