Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
E=mc² is Einstein's famous equation that relates energy (E) to mass (m) and the speed of light (c). It states that energy is equal to mass multiplied by the square of the speed of light.
Related terms
Mass-energy equivalence: This concept refers to the idea that mass and energy are interchangeable, as described by E=mc².
Speed of light: The speed at which electromagnetic waves travel through space, denoted by 'c' in the equation E=mc².
Conservation of energy: This principle states that energy cannot be created or destroyed but can only be converted from one form to another, as exemplified by E=mc².