According to special relativity, developed by physicist Albert Einstein in 1905, simultaneity does not exist. In other words, if two events occur in different locations and are physically separated, we cannot assert with absolute certainty that they occurred simultaneously.In fact, depending on the velocity and direction of the observer of those two events, one can say that one event occurred before the other.This theory is famous for being counterintuitive.However, the validity of a physical theory should not be based on whether it is intuitive to humans but on whether it can describe the universe we observe and make new predictions about its functioning.More information in:www.megainteresting.com