ved various concepts that demonstrate the full influence of the principle of special relativity. Perhaps the easiest aspect of relativity to understand is the idea that time is a fourth dimension. Now most people understand the concept of three-dimensional space, length, width, and height. Einstein in introducing special relativity also introduced a fourth dimension, time. The best way to explain this idea is to give a practical example. Harry sends a letter to Liz telling her to meet him at a restaurant and gives her directions. He tells her it is at Third St. and Baker Ave., and is on the fourth floor of the building. These three directions take care of length, width, and height. In addition, he also tells her to meet him at 8 PM. With the introduction of specified meeting time he has now introduced a fourth variable and thus a fourth dimension. Einstein tried to point out that all events are determined by their place both in space and in time.
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