Its consequences include the fact that if you hit a parked car at sixty miles per hour, the effect is the same as if you and the other car had a head-on collision, with each of you traveling thirty miles per hour.
Velocities add .
Special Relativity was published by Einstein in 1905, and explores the consequences of the Principle of Relativity for observers moving at constant velocities relative to one another. In other words, there is no way to distinguish uniform acceleration from a gravitational field . For Einstein, time is a dimension, like height, width and length. For Einstein, space and time are intimately wrapped up in each other, so that we talk instead of Spacetime Spacetime is the continuum in which the Universe is embedded. It has three dimensions of space and one of time, but is often represented in two-dimensional spacetime diagrams in which time is the vertical axis and the three dimensions of space are collapsed into the horizontal axis.