Physics · Theme A: Space, time and motion
A.5 — Galilean and special relativity
Physics · SL / HL · syllabus-mapped notes
Reference frames and Galilean relativity
Inertial reference frames, the Galilean transformation and velocity addition.
The postulates and Lorentz transformations
The two postulates of special relativity, the Lorentz transformations, γ, and relativistic velocity addition.
Space–time interval, proper time and length
The invariant space–time interval, and the meaning of proper time and proper length.
Time dilation and length contraction
Δt = γΔt₀, L = L₀/γ, the relativity of simultaneity, and muon-decay evidence.
Space–time diagrams
Constructing and reading space–time diagrams, world lines, and tan θ = v/c.