Einstein proposed his celebrated special theory of relativity in 1905. At the heart of his theory was a picture that even children can understand. His theory was the culmination of a dreamhe had had since the age of sixteen, when he asked the fateful question: What hapens if you outrace a light beam? As a youth, he knew that Newtonian mechanics described the motion of objects on the Earht and in the heavens, and that Maxwell’s theory described light. These were the two pillars of physics.The essence of Einstein’s genius was that he recognized that these two pillars were in contradiction. One of them must fall.
According to Newton, you could always outrace a light beam, since there was nothing special about the spead of light. This meant that the light beam must remain stationary as you raced alongside. But no one had ever seen a light wave that was totally stationary, that is like a frozen wave. Hance Newton’s theory didn’n make sence. Studying Maxwell’s theory, Einstein found the answer, he discovered something that even Maxwell didn’t know. That the speed of light was a constant, no matter how fast you moved. If you raced toward or away from a light beam, it still traveled at the same velocity, but this trait violets common sence. You can never race alongside a light beam, since it always moves away from you at a constant speed, no matter how fast you move.
In Newton’s theory the passage of time was uniformthrought the universe. One second on Earth was identical to one secon on Mars. Similarly, meter stics placed on the Earth had the same lenght as a meter stics on Mars.
According to Einstein if you were in speeding rocket ship, the passage of time inside the rocket would have to slow down with respect to someone on Earth. Time beats at different rates, depending on how fast you move. Furthermore, the space within that rocket ship would get compressed so that meter sticks could change in lenght, depending on your speed. And the mass of the rocket would increase as well.
Since Einstein derived his famous equation, literally millions of experiments have confirmed his revolutionary ideas.
For example, the GPS system, which can locate your position on the Earth, to within a few feet, would fail unlles one added in corrections due to relativity.
The most graphic illustration of this concept is found in atom smashers, in which scientists accelerate particles to nearly the speed of light. At the gigantic CERN accelerator, the Large Hadron Collider, outside Geneva, protons are accelerated to trillions of electron volts and they move very close to the speed of light.