# Physical Alphabet: Learn it Before You Learn Physics!

Physics utilizes Latin and Greek letters along with various symbols to express the laws of nature in equations. If you aspire to understand physics equations **to the best of your ability**, **present equations** to others, or even **formulate your own equations**, you must first master the *alphabet of physics*. Familiarize yourself with each symbol and learn its pronunciation.

Letters that are easily confused should not be used in equations at the same time!

Letter |
Pronunciation |
Usage in physics |

\(A\) | | Area, Activity |

\(B\) | | Magnetic flux density |

\(C\) | | Capacitance |

\(D\) | | Electric flux density |

\(E\) | | Electric field |

\(F\) | | Force |

\(G\) | | Gravitational constant |

\(H\) | | Magnetic field |

\(I\) | | Current |

\(J\) | | Unit: Joule, current density |

\(K\) | | Unit: Kelvin |

\(L\) | | Angular momentum, Inductance |

\( \Lambda \) | Lambda | Cosmological constant |

\(M\) | | Torque, Mass |

\(N\) | | Particle number |

\(P\) | | Power |

\(Q\) | | Charge, heat |

\( \nabla \) | Nabla | Derivative operator |

\( \Delta \) | Delta | Difference |

\( R \) | | Resistance |

\( S \) | | Entropy |

\( T \) | | Temperature |

\( U \) | | Voltage |

\( V \) | | Volume |

\( W \) | | Energy, work |

\( X \) | | Complex part of impedance |

\( Y \) | | Electrical conductance |

\( Z \) | | Atomic number, impedance |

\(a\) | | Acceleration |

\(b\) | | Damping constant |

\(c\) | | Specific capacitance |

\(d\) | | Thickness |

\(e\) | | Elementary charge |

\(f\) | | Frequency, focal length |

\(g\) | | Gravitational acceleration |

\(h\) | | Planck constant, height |

\(i\) | | Imaginary unit |

\(j\) | | Current density |

\(k\) | | Boltzmann constant |

\(l\) | | Length |

\(m\) | | Mass |

\(n\) | | Charge carrier density, quantum number |

\(p\) | | Momentum |

\(q\) | | Test charge |

\(r\) | | Radius |

\( \rho \) | Rho | Mass density |

\(s\) | | Distance |

\(t\) | | Time |

\(u\) | | Atomic mass unit |

\(v\) | | Velocity |

\( \Xi \) | Xi | Cascade particle |

\( \Gamma \) | Gamma | Decay width |

\( \Pi \) | Pi | Pressure |

\( \Omega \) | Omega | Unit: Resistance |

\( \Theta \) | Theta | Twisting angle |

\( \Phi \) | Phi | Magnetic flux |

\( \Psi \) | Psi | Wave function |

\( \Sigma \) | Sigma | Sum sign |

\( \delta \) | Delta | Loss angle |

\( \partial \) | Del | Partial derivative |

\( \epsilon \), \( \varepsilon \) | Epsilon | Vacuum permittivity |

\( \phi \), \( \varphi \) | Phi | Phase angle |

\( \alpha\) | Alpha | Angular acceleration, angle |

\( \beta \) | Beta | Angle |

\( \gamma \) | Gamma | Weight, Lorentz factor |

\( \hbar \) | h quer | Reduced Planck constant |

\( \eta \) | Eta | Viscosity |

\( \pi \) | Pi | Pi number, \( \pi \)-myon |

\( \sigma \) | Sigma | Conductivity |

\( \delta \) | Delta | Loss angle |

\( w \) | | Energy density |

\( x \) | | Space coordinate |

\( y \) | | Space coordinate |

\( z \) | | Space coordinate |

\( \lambda \) | Lambda | Wavelength |

\( \theta \), \( \vartheta \) | Theta | Angle |

\( \tau \) | Tau | Half-life |

\( \mu \) | Mu | Dipole moment |

\( \omega \) | Omega | Angular frequency |

\( \psi \) | Psi | Wave function |

\( \xi \) | Xi | Sound deflection |

The Latin letter "O, o" was not included in the alphabet because it can be confused with zero. Also the Greek letter \( \zeta \) (zeta) is omitted here, because it is used very rarely in physics and therefore, according to the Universaldenker minimalism, is omitted.