Writer and physicist Paul Davies has called “time” Einstein’s unfinished revolution. There are many questions about the nature of time. What is time? What causes time? Why time slows in gravity? Why time slows in motion? Is time a dimension? Aristotle had speculated that time may be motion. He however added that motion could be slower or faster but not time. Aristotle did not have the privilege of knowing about Einstein’s relativity in which time also becomes amenable to change. Similarly when Einstein was working to develop theory of general relativity and proposed the revolutionary idea that mass curves space he did not know that the universe was expanding. This discovery by astronomer Edwin Hubble came 13 years after Einstein had published his theory of General Relativity. Had Einstein known of this great discovery he may have incorporated these ideas into his theories. Conceptually it is easier to derive space curvature in an expanding universe as an area of slower expansion under the influence of gravitons. One of the most dramatic aspects of the universe is that it is expanding and the presence of motion, forces and curved space-time happens in he expanding space.
In the next few paragraphs I will show that time is an emergent concept. There is an underlaying process of motion and forces from which time emerges, however what we perceive as time is mostly an illusion. Our memory creates the illusion of the past. Conscious perception of events gives the feeling of present. Future is a mental construct patterned on the memory experience of the past. Concept of time emerges as our mind tries to make sense of the world around us which is filled with change.
Mc TAGGART ON THE ILLUSION OF TIME
John Ellis McTaggart (1908) and many other philosophers have proposed that the passage of time is an illusion suggesting that only the present is real. McTaggart is famous for his A, B and C series analysis of time. A brief review is as follows:
The earlier and later aspect of time is basically the same as the arrow of time. The birth of a person always comes before their death even as these events become part of the distant past. This is a fixed relationship so McTaggart asserts it must be more fundamental to time.
The past the present and the future aspect of time is constantly changing, future events are moving to the present and then into the past and then further back into the past. This aspect deals with the feeling of flow of time. This constantly changing relationship is also essential to the description of time. McTaggart felt that time is unreal because distinction of past present and future (a changing relationship) is more essential to time then the fixed relationship of earlier and later.
TIME AS MEMORY
McTaggart’s most interesting observation however is that historical events have same time characteristic as made up stories. For example made up stories, as well as past historical events have in them, the earlier and the later as well as the past the present and the future, thus suggesting that past really is more like memory of events and does not exist any more than imagination of a writer. The above point becomes more clear when we compare past present and future to other recording devices like laser discs CDs and hard drives.
PRESENT IS AN INFINITESIMAL?
Present is the most real perception of time however almost all of what we perceive as the present is already past. The present is a fleeting moment, whatever is happening now (present) is confined to an infinitesimally narrow point on the time line which is being encroached upon by what we think of as the past and the future.
Present resembles the sharp point of a recording laser or needle while past being a duration or extension resembles the recorded material like tape or CD.
