What is time and what causes time

 

Ruwan M Jayatunge M.D. 

Time is defined as the indefinite continued progress of existence and events in the past, present, and future regarded as a whole.  Time is the continued sequence of existence and events that occur in apparently irreversible succession from the past, through the present, into the future.  A definition of time can be given on the basis of the simple principle that each physical magnitude constitutes a feature of some physical carrier.   

Physics equations work equally well whether the time is moving forward into the future (positive time) or backward into the past (negative time.)   For Isaac Newton, time was separate from space and was considered to be a single line or railroad track, that was infinite in both directions In Newtonian physics, time is used as a parameter to describe the motion of objects. 

Einstein revealed that time can be considered as the fourth dimension. Einstein revealed that gravity also affects time. In a stronger gravitational field time passes more slowly. Molecular motion and interactions are also at work and are a part of the time.  It's important to indicate that time involves both motion and forces.  

The universe is thought to have originated in an event called the Big Bang about 13 billion years ago. We live in an expanding universe and the galaxies are receding from each other as a part of the universal expansion. Time began with the Big Bang.  The slowing of time without sliding into the past or the future suggests that time is a process and not a dimension. Time is the presence of motion and forces which is caused by the expansion of space.  Slowing of time in gravity and motion has a common denominator the expanding space providing a link between the expansion of space and time. 

Reference literature

A Simple definition of Time by Demetris T. Christopoulos 

What is time and what causes time by  Dr. Mohammad H. Khan

The Fabric of the Cosmos - by Brian Greene 

Time Definition- by  Osama Khalil

The Notion of Time in Special Relativity by Yefim Bakman and  Boris Pogorelsky