What is time?

From the stars to a single atom, every matter/mass is at motion, at different location, direction, speed, frequency or cycle. 

From momentum, matter and energy conservation laws, all matters will keep moving forever.

We see the motion, changing, cycling, invented the concept of time and use timers to measure it.  

Time is the passage of forever ongoing changing. All happening, all existing is at forever ongoing now. Past and future don't exist in reality.

From F=Ke x q1q2/rr, we know that all motions and actions are simultaneous throughout space. Time is forever ongoing now.

The whole universe lives at this forever ongoing very moment.

There is only one force exist. Coulomb's force coexisted with charged atom parts. This electrostatic force is the mother of all forces. magnetic force is circular electric force. gravity is net force between all charges in the masses. strong and weak force are imaginary. levity/universal repulsion force conducts light/energy/EMF throughout space simultaneously.