Here's why:
* Time dilation: As an object approaches the speed of light, time slows down for that object relative to a stationary observer. This effect is negligible at everyday speeds, but becomes significant as the object nears the speed of light.
* Length contraction: The length of an object moving at relativistic speeds appears to contract in the direction of motion from the perspective of a stationary observer. This effect is also negligible at low speeds but becomes significant as the object approaches the speed of light.
* Increase in mass: The mass of an object increases as its speed increases. This effect is also negligible at low speeds but becomes significant as the object approaches the speed of light.
Examples of when special relativity is important:
* Particle accelerators: Particles in particle accelerators reach speeds very close to the speed of light, and the effects of special relativity are crucial for understanding their behavior.
* GPS satellites: The clocks on GPS satellites are affected by special relativity due to their high speeds. These effects must be accounted for to ensure accurate GPS navigation.
* Astrophysical objects: Objects like pulsars and black holes move at speeds close to the speed of light, and their behavior is heavily influenced by special relativity.
In summary: While special relativity applies to all objects in motion, its effects are only noticeable at speeds approaching the speed of light.
