The Greek Alphabet

All 24 Greek letters, capital and lower case, with where each turns up in science, maths and everyday English.

Greek letters are everywhere once you can read them: π and Σ in maths, Δ for change, μ for micro, Ω for ohms, and fraternity names on sweatshirts. Each card shows a letter in both cases and asks you to type its name, in alphabetical order from alpha to omega. Most answers include a common use, which makes the letter easier to remember.

All 24 cards

  1. Α α

    Alpha

    α for angles; alpha particles.

  2. Β β

    Beta

    β for a stock’s volatility; beta software.

  3. Γ γ

    Gamma

    γ for gamma rays.

  4. Δ δ

    Delta

    Δ for change, as in Δt; river deltas are named for the triangle shape.

  5. Ε ε

    Epsilon

    ε for a very small quantity in maths.

  6. Ζ ζ

    Zeta

  7. Η η

    Eta

    η for efficiency in physics and engineering.

  8. Θ θ

    Theta

    θ for angles.

  9. Ι ι

    Iota

    As in “not one iota”: the smallest letter.

  10. Κ κ

    Kappa

  11. Λ λ

    Lambda

    λ for wavelength; anonymous functions in programming.

  12. Μ μ

    Mu

    μ for micro- (one millionth), as in μm; the mean in statistics.

  13. Ν ν

    Nu

    ν for frequency in physics.

  14. Ξ ξ

    Xi

  15. Ο ο

    Omicron

  16. Π π

    Pi

    π ≈ 3.14159, a circle’s circumference over its diameter; Π for a product.

  17. Ρ ρ

    Rho

    ρ for density and for correlation.

  18. Σ σ

    Sigma

    Σ for a sum; σ for standard deviation. At the end of a word it is written ς.

  19. Τ τ

    Tau

    τ for torque and for time constants.

  20. Υ υ

    Upsilon

  21. Φ φ

    Phi

    φ ≈ 1.618, the golden ratio.

  22. Χ χ

    Chi

    χ² for the chi-squared test.

  23. Ψ ψ

    Psi

    ψ for the wave function in quantum mechanics; the symbol of psychology.

  24. Ω ω

    Omega

    Ω for ohms; “alpha and omega” means the beginning and the end.