The speed of light is approximately 299,792,458 meters per second in a vacuum. This is also known as the universal speed limit, as nothing can travel faster than the speed of light.
The first successful measurement of the speed of light was done by Danish astronomer Ole Rømer in 1676. He observed the varying time it took for light to travel from Jupiter's moon Io to Earth as the two planets moved in their orbit.
According to Einstein's theory of relativity, the speed of light is a constant in all inertial frames of reference. However, some recent experiments have shown small variations in the speed of light, which may have been different in the early universe.
The speed of light plays a crucial role in the theory of relativity, which states that time appears to slow down for an object in motion as its speed approaches the speed of light. This is known as time dilation and has been observed in high-speed experiments.
According to our current understanding of physics, it is impossible for anything to travel faster than the speed of light. As an object approaches the speed of light, its mass and energy increase infinitely, making it impossible to reach or exceed this limit.