Pauli Exclusion Principle
A fundamental quantum law stating that two identical fermions cannot occupy the exact same quantum state simultaneously.
Governing formula
No two identical fermions can occupy the same quantum state: ψ(1,2) = -ψ(2,1)
SI unit
Dimensionless Quantum Law
In depth
Formulated by Wolfgang Pauli, this principle dictates that no two electrons in an atom can have identical values for all four quantum numbers (n, l, m_l, m_s), giving rise to electron shells and preventing matter collapse.
Examples in the real world
Preventing white dwarf stars and neutron stars from gravitational collapse due to electron and neutron degeneracy pressure.