A wealthy man threw a party in honor of his son's graduation from university. A poor man happened to be in the vicinity, and joined the party. Amidst all the commotion he was let in and seated at the far end of the table.

"Son," the wealthy man said, "share with us some of the great knowledge that you have acquired in the university."

"Well," began the son, "Copernicus proved that the earth turns on its axis."

"That is false!" came the objection from the poor man at the other end of the table.

"How do you know? Prove it!" shouted the student.

"It is very simple," replied the beggar. "If the earth turned on its axis, then the food that was placed at the head of the table would have by now come to this side of the room."

Today's joke was taken from ChabadRochester.com.