Theory of Relativity Quiz

Relativity

Theory of Special Relativity (1905)

• Introduced by Albert Einstein
• Postulates:
  • The laws of physics are the same for all observers in uniform motion relative to one another
  • The speed of light is always constant, regardless of the motion of the observer or the source of light
• Consequences:
  • Time dilation: time appears to pass slower for an observer in motion relative to a stationary observer
  • Length contraction: objects appear shorter to an observer in motion relative to a stationary observer
  • Relativity of simultaneity: two events that are simultaneous for one observer may not be simultaneous for another observer in a different state of motion
  • Equivalence of mass and energy (E=mc^2)

Theory of General Relativity (1915)

• Introduced by Albert Einstein
• Postulates:
  • Gravity is not a force, but rather the curvature of spacetime caused by the presence of mass and energy
  • The curvature of spacetime is directly related to the distribution and motion of mass and energy
• Consequences:
  • Gravitational time dilation: time passes slower near a massive object due to its gravitational field
  • Gravitational redshift: light is shifted towards the red end of the spectrum as it escapes a gravitational field
  • Bending of light: the path of light is curved by the presence of mass and energy
  • Black holes: regions of spacetime where gravity is so strong that not even light can escape

Key Concepts

• Spacetime: a four-dimensional fabric that combines space and time
• Lorentz transformation: a mathematical formula that describes how space and time measurements change for an observer in motion
• Inertial frame of reference: a frame of reference in which an object is at rest or moving with a constant velocity relative to the observer
• Proper time: the time measured by a clock in an inertial frame of reference
• Proper length: the length of an object measured in an inertial frame of reference