Physicists poke their noses into everything, from the smallest to the largest.
The diameter of a proton is about 0.000 000 000 000 0016 m.
Proxima Centauri, the nearest star to Earth, is 40,208,000,000,000,000 m away.
Obviously, when it comes to units, one size does not fit all. This is why the SI system provides for prefixes so that units of different sizes can be formed.
–
xmPhysics 