Mystery of Time 

On the Physics and Phenomenology of Time Ben Goertzel

In this book Zeh brings some clarity to a very murky problem: why are the future and the past so different? One need only to read the physics journals to see that this is a multi-faceted and very real issue that vexes the experts even now. To understand its seriousness, it is first necessary to see how similar the future and the past are. They don't seem so in everyday life: we remember the past but not the future, our actions affect the future but not the past, and so on. From this standpoint it is really quite surprising that the dynamical laws of physics - with one small exception - seem to be symmetrical under time reversal.

The Physical Basis of the Direction of Time by H. D. Zeh 

Time in Special and General Theory of Relativity.

The direction of time from past to future seemed to become even more illusionary when Albert Einstein's (1879–1955) Theory of Relativity succeeded in overcoming the Newtonian notion of absolute time. In his 1905 Special Theory of Relativity, Einstein stated that the time interval (and the distance) between two events depends on the observer's velocity relative to the events, while the velocity cannot exceed the speed of light.

In Einstein's theory, space and time together constitute the four-dimensional space-time, while each reference frame of an observer divides spacetime differently into a temporal and a spatial component relative to its state of velocity. There is no simultaneity of events and absolute duration of time for every observer, as well as no absolute spatial distance. Still, there is an objective causal connection between events, because one event cannot interact with another instantaneously, but only mediated by forces, whose propagation speed is final and equals or is less than the speed of light.

Time: Physical and Biological Aspects