What is ferm?

Ferm is a metric unit of length used in nuclear physics to express the size of atomic nuclei. It is equivalent to 10^-15 meters, which is approximately one femtometer. The ferm was named after Enrico Fermi, an Italian physicist who was a leader in the development of nuclear energy. The size of atomic nuclei is typically measured in fermis because they are much smaller than other objects we encounter in everyday life. For example, a typical atomic nucleus has a diameter of about 1 to 10 fermis, while a human hair has a diameter of approximately 100,000 to 1,000,000 nanometers, or 100,000 to 1,000,000,000 fermis. The use of fermis allows scientists to quantify and compare the size of different atomic nuclei.