Of all the inventors on this list that were eaten away by guilt, Albert Einstein likely lost the most sleep over his creation.
The world-famous scientist may not have helped build the first atom bomb (he was denied security clearance by the US), but his discoveries helped lead to its creation. Einstein’s famous equation E=mc2 described how energy was released in an atomic bomb, and gave scientists a roadmap for how to produce the final project.
In 1939, after German scientists split the uranium atom, Einstein wrote a letter to President Franklin Roosevelt urging him to invest in exploring the creation of bombs using this new discovery. Fear of the Nazis generating their own super weapon led to the formation of the Manhattan Project, which successfully designed the first atom bomb.
He eventually regretted his small role in the project. In an interview with Newsweek in 1947, he was quoted as saying that if he had "known that the Germans would not succeed in developing an atomic bomb, I would have done nothing."
