Observations of motion rely on your frame of reference. Experiments with light reveal that the speed of light is always the same, regardless of the motion of the light source or the motion of the observer! To understand this, think about a rocket docked on the Earth and another rocket traveling directly toward the Sun at great speed. The light from the Sun reaches each rocket at the same speed of 300 000 000 m/s.
The constant speed of light is the basis of Albert Einstein's special theory of relativity. He reasoned that space and time are connected into one whole, called space-time. You are constantly traveling through this combination of space and time. When you stand still, vou travel only through time. When you move, you travel through space as well as through time. Einstein's theory predicts that if you could move at the speed of light, you would travel only through space, not through time.
The constant speed of light is the basis of Albert Einstein's special theory of relativity. He reasoned that space and time are connected into one whole, called space-time. You are constantly traveling through this combination of space and time. When you stand still, vou travel only through time. When you move, you travel through space as well as through time. Einstein's theory predicts that if you could move at the speed of light, you would travel only through space, not through time.
