The history and future of physics changed about 80 years ago, when a young Swiss patent clerk named Albert Einstein quietly but firmly showed a multitude of chagrined and chastened physicists the direction they would have to take in order to achieve the necessary modification of the great natural laws of physics, which had somehow to be accomplished.
The single hypothesis Einstein proposed was simple. To wit, "Let us take the basic assumption that the measured speed of light (or of any electromagnetic wave) will always be the same anywhere in the Universe, no matter what the motion of the observer who is making the measurement, and no matter what the motion of the light source."
Albert Einstein charted a course through a no-man's land, and then proceeded to follow it to the bitter end. But what were the implications and conclusions that had to be drawn if physicists were to accept Einstein’s very practical viewpoint and his basic postulate that the velocity of light remained constant under all circumstances? Among other things like the theory that showed that, no matter how much energy one gave to a particle, one could not accelerate it to a speed greater than the speed of light. It also showed that the mass of the particle was a measure of its internal energy, thereby giving a clue to the possibility of obtaining nuclear energy; it also provided the basic equations for describing the motion of highly energetic particles; and led to the prediction and production of antimatter. It also predicted (which has since been proven experimentally) that clocks, while moving quickly, run slower than identical clocks at rest. This is known as Time Dialation. Time dialation governs all processes in the moving frame of reference. Biological processes proceed at the same rates as measured by clocks at the same velocity (otherwise one could tell time was slowing down because they would move incredibly fast). Therefore, if the clocks in a moving frame run more slowly (by...