The equation of motion for spinless particles, also known as the Klein–Gordon–Fock equation:

, where:

c = Speed of Light (m/s)

= Wave Function

t = Time (s)

= Laplacian

, where:

I = Specific Radiative Intensity ((W*s)/(m^{2}*sr))

h = Planck Constant (J*s)

= Frequency (Hz)

c = Speed of Light (m/s)

e = Euler's Number

k = Thermal Conductivity (W/(m*K))

T = Temperature (K)

Also known as Planck's Relation, the energy of a photon is given by:

, where:

E = Energy (J)

h = Planck's Constant (J*s)

f = Frequency (Hz)

, where:

R = Rydgberg Constant (1/m)

m = Electron Mass (kg)

e = Elementary Charge (C)

= Electric Constant (F/m)

h = Planck Constant (J*s)

c = Speed of Light (m/s)

, where:

= Wavelength of light emitted in spectral lines (m)

R = Rydberg Constant (1/m)

Z = Atomic Number

n_{1}_{ }< n_{2} and give a series of spectral lines.