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?” one young man blurted out.

“To save lives,” the professor responded.

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 without saying a word. Finally, the professor continued, “Physics saves lives because it keeps certain people out of medical school.”