Until then?

In his early 30s, Frank Oppenheimer, the experimental physicist and educator (and brother of J. Robert Oppenheimer, the “father the atomic bomb”), discovered the process for isolating and harvesting the weapons-grade uranium isotopes needed to build the first successful atom bomb.

Revised 1:30 p.m., September 16, 2011. Had to make a change to comply with Facebook rules. Don't want to piss off Mr. Zuckerberg. He knows where you live. Also, it's not a "contest." It's "an interactive event of epic proportions." Yeesh. Some people.