4D Time, the great deceiver

摘要

Space consists of three dimensions. Time, we are told, is also a dimension. So how come it is so different? Answer: it isn't. "Space and time are notrnconcepts that can be considered independently of one another," says physicist Roger Penrose in his book Gravitation. In Einstein's special theory of relativity, they dissolve into one entity. Two objects that to one person seem separated only in space can to another seem divided by space and time. Similarly, two events that seem to be separated only in time might from another perspective occur in different places as well.