Today's Laugh

A photon and an ion went to the airport. When they got there, the other passengers were surprised to see the ion handed his ticket without paying, and the photon get waved through security.

"What gives?" an irate passenger asked. "Why does the photon get to go through security?"

"Oh," said the man behind the desk. "We know he's traveling light."

"And the ion?"

"He was charged earlier."