Planck length facts for kids
It is about 1.6 x 10−35 m or about 10−20 times the size of a proton. It is one of the Planck units, defined by Max Planck. It is an important length for quantum gravity because it may be the size of the smallest black holes.de:Planck-Einheiten#Definitionen
Planck length Facts for Kids. Kiddle Encyclopedia.