Science: Atom Smasher

When the munitions ship Mont Blanc exploded in the harbor of Halifax, N.S. on Dec. 6, 1917, the shock was felt more than 150 miles away. The explosion killed more than 1,100, laid waste two square miles of the city. The Mont Blanc carried 3,000 tons of TNT. The single atomic bomb which fell on Hiroshima in Japan this week exploded with approximately seven times the force of that tremendous charge.

How the atomic explosive is made is one of the world's most closely guarded secrets. But the fundamental principle behind it can be...