Special Relativity (1905):

• Introduce Albert Einstein’s first major breakthrough: the Theory of Special Relativity.
• Key Concepts:
  • The Speed of Light is Constant: In all inertial frames of reference, the speed of light is the same, regardless of the motion of the observer or light source.
  • Time Dilation: Moving clocks tick more slowly compared to stationary ones (example: astronauts traveling at near-light speed).
  • Length Contraction: Objects moving at high speeds appear contracted along the direction of motion.
  • E=mc²: Mass and energy are interchangeable (the famous equation).
• Examples: GPS satellites must account for time dilation due to their relative motion to Earth.