Skip to main content


High-Tech Channel Hitachi High-Tech GLOBAL

A unit that gets its name from Hideki Yukawa!

Symbol: Y / Base data: length.
Unit of length used in atomic physics, which is about 10-15 m

Unit of length used in atomic physics

In the field of atomic physics, having a unit for extremely small lengths is very useful. I mean, saying 1/1000000000000000 m is a bit of a mouthful. This represents 1 yukawa. This unit’s name is derived from Hideki Yukawa. Unfortunately, the SI unit, “femto”, which indicates the same length, has become the standard measurement.