Euler’s identity is a mathematical beauty that ties five fundamental mathematical constants in mathematics together. In the equation, we have e, the base of natural logarithms, i, the imaginary unit, π, the ratio of the circumference of a circle to its diameter. This identity shows a profound connection between the most fundamental numbers in mathematics.
Boltzmann’s Constant
The fundamental constant of physics, the Boltzmann constant, is one of the seven "defining constants" that have been given exact definitions.