Final answer:
Effects of the special theory of relativity at high speeds include time dilation, length contraction, increased momentum, and mass-energy equivalence (E = mc^2). Observers in different frames of reference will disagree on measurements of time and length, and these effects only become noticeable as speeds approach that of light.
Step-by-step explanation:
The special theory of relativity has several profound effects for objects moving at significant fractions of the speed of light. These include time dilation, where time appears to slow down for the moving object relative to a stationary observer, and length contraction, where the object appears to contract along the direction of motion. Additionally, an increase in momentum and the equivalence of mass and energy as described by the famous equation E = mc2 are also consequences. When discussing an astronaut moving at a high speed relative to Earth:
- (a) The astronaut does not observe any change in the rate of their own clocks.
- (b) They see Earth-bound clocks ticking slower.
- (c) They do not perceive their ship as shortened.
- (d) The distance between stars lying on the lines parallel to their motion contracts.
- (e) An Earth-bound observer and the astronaut will disagree on the velocity of the astronaut relative to Earth due to these relativistic effects.
These effects are not commonly noticed in everyday life because they only become significant when an object's speed approaches that of light, which is much faster than typical human experiences with cars and airplanes.