Final answer:
The notion that no physical object can travel faster than the speed of light, including an electron, is rooted in Einstein's theory of special relativity, which contradicts Newtonian mechanics where velocities were considered additive. Maxwell's equations support the constant speed of light in a vacuum, cementing the concept that velocities do not simply add up when approaching the speed of light.
Step-by-step explanation:
In Einstein's theory of relativity, the conclusion that nothing can travel faster than the speed of light contradicted the older Newtonian notion that velocities are additive. This means in the old framework, if you threw a ball forward from a moving vehicle, the ball's speed relative to a stationary observer would be the sum of the vehicle's speed and the speed at which you threw the ball. However, for an electron or any physical object, Einstein's special relativity posits that the maximum speed is the speed of light, or approximately 3.00×108 m/s, and this speed cannot be exceeded, regardless of how the speeds are combined.
Maxwell's equations also support this conclusion, as they imply that light in a vacuum must always travel at this constant speed c relative to any observer. Consequently, Einstein dismissed the Newtonian addition of velocities for light, reinforcing that an object with mass cannot travel at such extreme speeds. This clash between classical physics and relativity highlights the fundamental changes that Einstein's theories brought to our understanding of motion and the fabric of space-time itself.
Furthermore, according to special relativity, if you were on a spaceship traveling at nearly the speed of light and projected an object forward, an observer on Earth still wouldn't see the object moving at a speed exceeding light. This is because the speed of light is an absolute maximum that cannot be surpassed in the vacuum of space. This phenomenon is a direct consequence of the relativistic physics, which redefined how we measure and perceive motions at high velocities.