Special relativity

Science

Definition

Special relativity is Einstein's theory describing how space and time behave for objects moving at constant velocities near the speed of light. It establishes that the speed of light is constant for all observers, time dilates for fast-moving objects, and mass and energy are equivalent.

Examples

  • GPS satellites adjusting their clocks for relativistic time dilation to maintain accuracy
  • Muons created in the upper atmosphere reaching Earth's surface because their time is dilated
  • Particle accelerators needing enormous energy to push particles closer to light speed
Key Fact

E = mc²; nothing with mass can reach the speed of light (c ≈ 3 × 10⁸ m/s)

Related Terms

Nuclear physics Fission and fusion Conservation of energy

Study This Concept

Practice special relativity with free review games in these units:

Physics Unit 10: Modern Physics