The Cambridge Handbook of Physics Formulas
Index from 'Kirchhoff's law' to 'ordinary modes' 
Kirchhoff's (radiation) law [5.180], 120
KIRCHHOFF'S DIFFRACTION FORMULA, 166
KIRCHHOFF'S LAWS, 149
Klein-Gordon equation [4.181], 104
Klein-Nishina cross-section [7.243], 155
Knudsen flow [5.99], 113
Kronecker delta [2.443], 50
kurtosis estimator [2.546], 57
ladder operators (angular momentum) [4.108], 98
Lagrange's identity [2.7], 20
Lagrangian (dimensions), 17
LAGRANGIAN DYNAMICS, 79
Lagrangian of
     charged particle [3.217], 79
     particle [3.216], 79
     two mutually attracting bodies [3.85], 69
Laguerre equation [2.348], 43
Laguerre polynomials (associated), 96
Lamé coefficients [3.240], 81
LAMINAR VISCOUS FLOW, 85
Landé g-factor [4.146], 100
Landau diamagnetic susceptibility [6.80], 133
Landau length [7.249], 156
Langevin function (from Brillouin fn) [4.147], 101
Langevin function [7.111], 144
Laplace equation
     definition [2.340], 43
     solution in spherical harmonics [2.441], 49
Laplace series [2.440], 49
Laplace transform
     convolution [2.517], 55
     definition [2.515], 55
     derivative of transform [2.521], 55
     inverse [2.519], 55
     of derivative [2.520], 55
     substitution [2.522], 55
     translation [2.524], 55
LAPLACE TRANSFORM PAIRS, 56
LAPLACE TRANSFORM THEOREMS, 55
Laplace transforms, 55
Laplace's formula (surface tension) [3.337], 88
Laplacian
     cylindrical coordinates [2.46], 23
     general coordinates [2.48], 23
     rectangular coordinates [2.45], 23
     spherical coordinates [2.47], 23
LAPLACIAN (SCALAR), 23
lapse rate (adiabatic) [3.294], 84
Larmor frequency [7.265], 157
Larmor radius [7.268], 157
Larmor's formula [7.132], 146
laser
     cavity Q [8.126], 174
     cavity line width [8.127], 174
     cavity modes [8.124], 174
     cavity stability [8.123], 174
     threshold condition [8.129], 174
LASERS, 174
latent heat [5.48], 109
lattice constants of elements, 124
Lattice dynamics, 129
LATTICE FORCES (SIMPLE), 131
lattice plane spacing [6.11], 126
LATTICE THERMAL EXPANSION AND CONDUCTION, 131
lattice vector [6.7], 126
latus-rectum [3.109], 71
Laue equations [6.28], 128
Laurent series [2.169], 31
LCR circuits, 147
LCR DEFINITIONS, 147
least-squares fitting, 60
Legendre equation
     and polynomials [2.422], 47
     definition [2.344], 43
LEGENDRE POLYNOMIALS, 47
Leibniz theorem [2.297], 40
length (dimensions), 17
Lennard-Jones 6-12 potential [6.52], 131
lens blooming [8.7], 162
LENSES AND MIRRORS, 168
lensmaker's formula [8.66], 168
Levi-Civita symbol (3-D) [2.444], 50
l'Hôpital's rule [2.132], 28
LIéNARD-WIECHERT POTENTIALS, 139
light (speed of), 6, 7
LIMITS, 28
line charge (electric field from) [7.29], 138
line fitting, 60
Line radiation, 173
line shape
     collisional [8.114], 173
     Doppler [8.116], 173
     natural [8.112], 173
line width
     collisional/pressure [8.115], 173
     Doppler broadened [8.117], 173
     laser cavity [8.127], 174
     natural [8.113], 173
     Schawlow-Townes [8.128], 174
linear absorption coefficient [5.175], 120
linear expansivity (definition) [5.19], 107
linear expansivity (of a crystal) [6.57], 131
linear regression, 60
linked flux [7.149], 147
liquid drop model [4.172], 103
litre (unit), 5
local civil time [9.4], 177
local sidereal time [9.7], 177
local thermodynamic equilibrium (LTE), 116, 120
ln(1+x) (series expansion) [2.134], 29
logarithm of complex numbers [2.163], 30
logarithmic decrement [3.202], 78
London's formula (interacting dipoles) [6.50], 131
longitudinal elastic modulus [3.241], 81
look-back time (cosmological) [9.94], 184
Lorentz
     broadening [8.112], 173
     constant [6.66], 132
     contraction [3.8], 64
     factor (g) [3.7], 64
     force [7.122], 145
     gauge condition [7.43], 139
LORENTZ (SPACETIME) TRANSFORMATIONS, 64
Lorentz factor (dynamical) [3.69], 68
Lorentz transformation
     in electrodynamics, 141
     of four-vectors, 65
     of momentum and energy, 65
     of time and position, 64
     of velocity, 64
Lorentz-Lorenz formula [7.93], 142
Lorentzian distribution [2.556], 58
Lorentzian (Fourier transform of) [2.506], 54
lumen (unit), 4
luminance [5.168], 119
luminosity distance [9.89], 184
luminosity-magnitude relation [9.31], 179
luminous
     density [5.160], 119
     efficacy [5.169], 119
     efficiency [5.170], 119
     energy [5.157], 119
     exitance [5.162], 119
     flux [5.159], 119
     intensity (dimensions), 17
     intensity [5.166], 119
lux (unit), 4
Mach number [3.315], 86
Mach wedge [3.328], 87
Maclaurin series [2.126], 28
MACROSCOPIC THERMODYNAMIC VARIABLES, 115
Madelung constant (value), 9
Madelung constant [6.55], 131
magnetic
     diffusivity [7.282], 158
     flux quantum, 6, 7
     monopoles (none) [7.52], 140
     permeability, m, mr[7.107], 143
     quantum number [4.131], 100
     scalar potential [7.7], 136
     susceptibility, cH, cB[7.103], 143
     vector potential
         definition [7.40], 139
         from J [7.47], 139
         of a moving charge [7.49], 139
magnetic dipole, see dipole
magnetic field
     around objects, 138
     dimensions, 17
     energy density [7.128], 146
     Lorentz transformation, 141
     static, 136
     strength ( H) [7.100], 143
     thermodynamic work [5.8], 106
     wave equation [7.194], 152
MAGNETIC FIELDS, 138
magnetic flux (dimensions), 17
magnetic flux density (dimensions), 17
magnetic flux density from
     current [7.11], 136
     current density [7.10], 136
     dipole [7.36], 138
     electromagnet [7.38], 138
     line current (Biot-Savart law) [7.9], 136
     solenoid (finite) [7.38], 138
     solenoid (infinite) [7.33], 138
     uniform cylindrical current [7.34], 138
     waveguide [7.190], 151
     wire [7.34], 138
     wire loop [7.37], 138
MAGNETIC MOMENTS, 100
magnetic vector potential (dimensions), 17
MAGNETISATION, 143
magnetisation
     definition [7.97], 143
     dimensions, 17
     isolated spins [4.151], 101
     quantum paramagnetic [4.150], 101
magnetogyric ratio [4.138], 100
MAGNETOHYDRODYNAMICS, 158
magnetosonic waves [7.285], 158
MAGNETOSTATICS, 136
magnification (longitudinal) [8.71], 168
magnification (transverse) [8.70], 168
magnitude (astronomical)
     -flux relation [9.32], 179
     -luminosity relation [9.31], 179
     absolute [9.29], 179
     apparent [9.27], 179
major axis [3.106], 71
Malus's law [8.83], 170
Mars data, 176
mass (dimensions), 17
mass absorption coefficient [5.176], 120
mass ratio (of a rocket) [3.94], 70
MATHEMATICAL CONSTANTS, 9
Mathematics, 19-62
matrices (square), 25
MATRIX ALGEBRA, 24
matrix element (quantum) [4.32], 92
maxima [2.337], 42
MAXWELL'S EQUATIONS, 140
MAXWELL'S EQUATIONS (USING D AND H), 140
MAXWELL'S RELATIONS, 109
Maxwell-Boltzmann distribution
     mean speed [5.86], 112
     most probable speed [5.88], 112
     rms speed [5.87], 112
     speed distribution [5.84], 112
MAXWELL-BOLTZMANN DISTRIBUTION, 112
mean
     arithmetic [2.109], 27
     geometric [2.110], 27
     harmonic [2.111], 27
mean estimator [2.542], 57
mean free path
     and absorption coefficient [5.175], 120
     Maxwell-Boltzmann [5.89], 113
mean intensity [5.172], 120
mean-life (nuclear decay) [4.165], 103
mega, 5
melting points of elements, 124
meniscus [3.339], 88
Mensuration, 35
Mercury data, 176
method of images, 138
metre (unit), 4
metric elements and coordinate systems, 21
MHD equations [7.283], 158
micro, 5
microcanonical ensemble [5.109], 114
micron (unit), 5
microstrip line (impedance) [7.184], 150
Miller-Bravais indices [6.20], 126
milli, 5
minima [2.338], 42
minimum deviation (of a prism) [8.74], 169
minor axis [3.107], 71
minute (unit), 5
mirror formula [8.67], 168
Miscellaneous, 18
mobility (dimensions), 17
mobility (in conductors) [6.88], 134
modal dispersion (optical fibre) [8.79], 169
modified Bessel functions [2.420], 47
modified Julian day number [9.2], 177
modulus (of a complex number) [2.156], 30
MOIRé FRINGES, 35
molar gas constant (dimensions), 17
molar volume, 9
mole (unit), 4
molecular flow [5.99], 113
moment
     electric dipole [7.81], 142
     magnetic dipole [7.94], 143
     magnetic dipole [7.95], 143
moment of area [3.258], 82
moment of inertia
     cone [3.160], 75
     cylinder [3.155], 75
     dimensions, 17
     disk [3.168], 75
     ellipsoid [3.163], 75
     elliptical lamina [3.166], 75
     rectangular cuboid [3.158], 75
     sphere [3.152], 75
     spherical shell [3.153], 75
     thin rod [3.150], 75
     triangular plate [3.169], 75
     two-body system [3.83], 69
moment of inertia ellipsoid [3.147], 74
MOMENT OF INERTIA TENSOR, 74
moment of inertia tensor [3.136], 74
MOMENTS OF INERTIA, 75
momentum
     definition [3.64], 68
     dimensions, 17
     generalised [3.218], 79
     relativistic [3.70], 68
MOMENTUM AND ENERGY TRANSFORMATIONS, 65
MONATOMIC GAS, 112
monatomic gas
     entropy [5.83], 112
     equation of state [5.78], 112
     heat capacity [5.82], 112
     internal energy [5.79], 112
     pressure [5.77], 112
monoclinic system (crystallographic), 127
MOON DATA, 176
motif [6.31], 128
motion under constant acceleration, 68
Mott scattering formula [4.180], 104
m, mr (magnetic permeability) [7.107], 143
multilayer films (in optics) [8.8], 162
multimode dispersion (optical fibre) [8.79], 169
multiplicity (quantum)
     j [4.133], 100
     l [4.112], 98
multistage rocket [3.95], 70
MULTIVARIATE NORMAL DISTRIBUTION, 58
MUON CONSTANTS, 9
mutual
     capacitance [7.134], 146
     inductance (definition) [7.147], 147
     inductance (energy) [7.135], 146
mutual coherence function [8.97], 172
nabla, 21
NAMED INTEGRALS, 45
nano, 5
natural broadening profile [8.112], 173
natural line width [8.113], 173
Navier-Stokes equation [3.301], 85
nearest neighbour distances, 127
Neptune data, 176
neutron
     Compton wavelength, 8
     magnetic moment, 8
     mass, 8
     molar mass, 8
NEUTRON CONSTANTS, 8
neutron star degeneracy pressure [9.77], 183
newton (unit), 4
Newton's law of Gravitation [3.40], 66
Newton's lens formula [8.65], 168
NEWTON'S RINGS, 162
Newton's rings [8.1], 162
Newton-Raphson method [2.594], 61
NEWTONIAN GRAVITATION, 66
noggin, 13
NOISE, 117
noise
     figure [5.143], 117
     Johnson [5.141], 117
     Nyquist's theorem [5.140], 117
     shot [5.142], 117
     temperature [5.140], 117
normal (unit principal) [2.285], 39
normal distribution [2.553], 58
normal plane, 39
NUCLEAR BINDING ENERGY, 103
NUCLEAR COLLISIONS, 104
NUCLEAR DECAY, 103
nuclear decay law [4.163], 103
nuclear magneton, 7
number density (dimensions), 17
numerical aperture (optical fibre) [8.78], 169
NUMERICAL DIFFERENTIATION, 61
NUMERICAL INTEGRATION, 61
Numerical methods, 60
NUMERICAL SOLUTIONS TO f(x) = 0, 61
NUMERICAL SOLUTIONS TO ORDINARY DIFFERENTIAL EQUATIONS, 62
nutation [3.194], 77
Nyquist's theorem [5.140], 117
OBLIQUE ELASTIC COLLISIONS, 73
obliquity factor (diffraction) [8.46], 166
obliquity of the ecliptic [9.13], 178
observable (quantum physics) [4.5], 90
Observational astrophysics, 179
OBSERVATIONAL COSMOLOGY, 184
octahedron, 38
odd functions, 53
ODEs (numerical solutions), 62
ohm (unit), 4
Ohm's law (in MHD) [7.281], 158
Ohm's law [7.140], 147
opacity [5.176], 120
open-wire transmission line [7.182], 150
operator
     angular momentum
         and other operators [4.23], 91
         definitions [4.105], 98
     Hamiltonian [4.21], 91
     kinetic energy [4.20], 91
     momentum [4.19], 91
     parity [4.24], 91
     position [4.18], 91
     time dependence [4.27], 91
OPERATORS, 91
optic branch (phonon) [6.37], 129
optical coating [8.8], 162
optical depth [5.177], 120
OPTICAL FIBRES, 169
optical path length [8.63], 168
Optics, 161-174
ORBITAL ANGULAR DEPENDENCE, 97
ORBITAL ANGULAR MOMENTUM, 98
orbital motion, 71
orbital radius (Bohr atom) [4.73], 95
order (in diffraction) [8.26], 164
ordinary modes [7.271], 157