Example image of eyePlorer eyePlorer map for 'Dimensionless quantity': Dimensional analysis Quantity Units of measurement Product (mathematics) Ratio Economics Engineering Mathematics Physics Buckingham π theorem Dependent and independent variables Dimension Variable (mathematics) Density Diameter Electric power Magnetic stirrer Speed Viscosity International Committee for Weights and Measures Power number Reynolds number Angle Radian Degree (angle) Parts-per notation Boltzmann constant Dimensionless physical constant Electric charge Gravitational constant Length Mass Planck constant Speed of light Temperature Time Natural units Planck units Systems of measurement Coupling constant Electromagnetic force Electron Fine-structure constant Invariant mass Proton Proton-to-electron mass ratio Elementary particle Gravitational coupling constant Strong interaction John C. Baez