Richard Feynman the safe-cracker While he was working on the Manhattan project, Feynman developed a hobby where he would crack open the safes at Los Alamos. The safes involved inputting 3 numbers between 0 and 99. A possible passcode could be 97-34-04.

In total, there were a million possible combinations. On the average, it would take you a month if all you did, day and night, was dedicate your time to work through the combinations.

After tinkering around with it, Feynman noticed that the safes weren't mechanically perfect and had a tolerance of +/- 2 on each number.

For example if 17-42-49 was the set passcode, 15-44-47 and 16-43-51 would also open the safe. With this piece of knowledge, Feynman could check every 5'th number and reduce the number of combinations to 8,000. If you worked through all the combinations, the safe could be cracked, on average, within 6 hours.

Feynman also noticed that most people will set their safe to a some kind of a date in the past. With 30 days in a month, 12 months and some year between 1900 and 1942 there are quite a few combinations. But taking into account the tolerance of the mechanism, there were only 162 combinations. With these few combinations, it would take Feynman 6 minutes to crack the safe on average.

So Feynman would go into his colleagues offices carrying a big bag with screwdrivers, picks and all sorts of things people would think you cracked a safe with. 6 minutes later he'd come out of the office with a cracked safe without even using the materials. Sometimes if he'd finish early, he'd wait for a while and then come out with some sweat on his brow and deceive his colleagues into thinking that cracking a safe is hard physical work.

Everyone at the Manhattan project thought Feynman knew how to use picks but he just cracked safes using human nature, the tolerance of the mechanism and his artful deviousness.