Beta (letter)
| Greek letters | |
| Α α Alpha | Β β Beta |
| Γ γ Gamma | Δ δ Delta |
| Ε ε Epsilon | Ϝ ϝ Digamma |
| Ζ ζ Zeta | Η η Eta |
| Θ θ Theta | Ι ι Iota |
| Κ κ Kappa | Λ λ Lambda |
| Μ μ Mu | Ν ν Nu |
| Ξ ξ Xi | Ο ο Omicron |
| Π π Pi | Ϻ ϻ San |
| Ϙ ϙ Qoppa | Ρ ρ Rho |
| Σ σ Sigma | Τ τ Tau |
| Υ υ Upsilon | Φ φ Phi |
| Χ χ Chi | Ψ ψ Psi |
| Ω ω Omega | Ϡ ϡ Sampi |
| Greek alphabet | |
Beta (upper case Β, lower case β) is the 2nd letter of the Greek alphabet. In the system of Greek numerals it has a value of 2. Beta should not be confused with a similar-looking but unrelated letter in German language orthography, ÃÂÃÂ, which denotes a long "s" sound.
The lower-case letter β is used as the symbol for:
- The beta particle and beta decay in particle physics.
- The speed of an object relative to the speed of light (β = v/c) in special relativity theory.
Letters that arose from Beta include the Roman B and the Cyrillic letters Be and Ve.