For more than 100 years we believe time is the 4th dimension of space-time that is the fundamental arena of the universe. We do not have a single data confirming that time has physical existence and is the 4th dimension of space. Advances of Relativity are in the development of the time-invariant universal space model as the fundamental arena of the universe. In the universe there is no physical time, there is no past, no present, no future.
