The physicist

A physicist is giving a lecture at a Jewish seniors residence and explaining
that in 4 and 1/2 billion years the sun will exhaust itself of fuel and burn
out and all life at we know it in the solar system will end.
Upset, Saul Epstein yells out, "Is there anything we can do professor? Can
we form any congressional committees, or donate money for research?"
The physicist responds, "Sir, why are you so upset? This won't happen for 4
and a half billion years?"
"Oh, thank God," says Mr. Epstein. "I thought you said it would happen in 4
and a half million years."