Posts Tagged ‘Fermi problem


How many physicists live in New Mexico?

In honor of Nobel prize-winning physicist Enrico Fermi (born on this day in 1901), we take a look at the famous “Fermi Problem.” Fermi loved making students think while teaching them the value of approximation when searching for answers. He did this through what came to be known as “Fermi Problems” — outrageous problems to solve immediately, but for which you don’t have enough — or any — data to solve normally. Instead of gathering data and analyzing it, Fermi wanted you to make a series of observations and assumptions, and then build your solution from those. He felt that any incorrect assumptions you made in one part of the problem would balance themselves out with incorrect assumptions in another part of the problem, leaving your solution very close to the actual number. (Frighteningly, this logic often works.)

A classic Fermi problem (usually attributed to Fermi himself) is “How many piano tuners are there in Chicago?” Wikipedia walks through the solution to the problem, complete with the various assumptions made along the way.