Earth Similarity Index
Length of the internal bisector of a triangle
Electrical conductivity (general definition)
Mass vaccination (critical immunisation threshold)
Regular Icosahedron (Surface Area)
Planck's law ( by the Frequency)
Ideal gas law (Common form)
Diametral pitch (transverse) - gears
Brinell scale ( using the SI units)
Knudsen number (For a Boltzmann gas)