01
Postulates
- The laws of physics take the same form in all inertial frames.
- The speed of light in vacuum is invariant for inertial observers.
02
Spacetime
c²Δt² - Δx² - Δy² - Δz² = invariant
Space and time combine into a four-dimensional spacetime structure whose interval remains invariant between inertial observers.
03
Mass-Energy Relation
E = mc²
Rest mass contributes to the total energy of a system. More generally, relativistic energy and momentum satisfy the energy-momentum relation.
E² = p²c² + m²c⁴