If you were somehow able to throw an object horizontally at near-light speeds, several interesting and counterintuitive effects would come into play due to the principles of special relativity. Let's explore some of these consequences:
Time dilation: According to special relativity, as an object approaches the speed of light, time dilation occurs. Time dilation means that time slows down for the object relative to an observer at rest. Therefore, from your perspective as the thrower, time would pass more slowly for the object as it approaches the speed of light. However, the effect would not be noticeable to you because you are also experiencing time dilation.
Length contraction: Another consequence of special relativity is length contraction. As an object moves at high speeds, it appears shorter in the direction of its motion when observed by an observer at rest. Therefore, the length of the object you throw would appear contracted in the direction of its motion.
Energy requirements: As an object approaches the speed of light, its kinetic energy increases dramatically. According to Einstein's mass-energy equivalence principle (E=mc²), the energy of an object is directly related to its mass. As the object's speed increases, its relativistic mass also increases. Consequently, it would require an enormous amount of energy to accelerate an object with mass to near-light speeds.
Interaction with the surrounding environment: As the thrown object approaches the speed of light, its interactions with the surrounding environment would become increasingly complex. For instance, the air molecules in its path would be compressed and ionized, leading to the generation of intense radiation and shockwaves. These effects would be similar to what occurs with high-speed particles in particle accelerators.
Gravitational effects: Near-light-speed objects would also experience gravitational effects. According to general relativity, the theory that describes gravity, objects with mass can cause the curvature of spacetime. As the thrown object accelerates, its gravitational field would become stronger, affecting the trajectory and potentially causing gravitational lensing or other distortions.
It's important to note that achieving near-light speeds for macroscopic objects like those we interact with in our everyday lives is currently beyond our technological capabilities. The effects mentioned above are based on the principles of special relativity, but they are hypothetical for objects with significant mass moving at such speeds.