E equals MC squared – you may remember it has something to do with energy and mass. But did you know Einstein's little equation opened the inner structure of the Universe? That it fired the Big Bang, and gave us the Atomic Bomb, Geiger Counters, smoke detectors and computers? In this hour of To the Best of Our Knowledge, the biography of the world's most famous equation. Also, Einstein in love. And master cryptographers.

Computer security expert Bruce Schneier has lost his faith in cryptography's ability to protect us on-line. He tells Steve Paulson just how risky cyberspace can be. Schneier's book is "Secrets and Lies: Digital Security in a Networked World."

Simon Singh is the author of "The Code Book: The Science of Secrecy from Ancient Egypt to Quantum Cryptography." He talks with Jim Fleming about the ancient and still on-going battle between code-makers and code-breakers.

David Bodanis is the author of "E=mc2: A Biography of the World's Most Famous Equation." He tells Steve Paulson what the equation means, and some of the amazing things it has led to, from the Big Bang and the atomic bomb to smoke detectors and computers. Also, Dennis Overbye, deputy science editor of the New York Times, is the author of "Einstein in Love: A Scientific Romance." Overbye tells Anne Strainchamps that Einstein led a lively and sometimes illicit love life. The great scientist was a genius, but also a cheat and a rogue.

Distribution dates:

• week of 12/10/2000 - hour 2