The velocity of an event is its combined speed and direction.
The velocity of a body in motion varies according to the forces which influence it.
The combined speed and direction of a ball thrown into the air depends on the direction the ball is thrown, its trajectory, the density of the air, the wind velocity, the mass of the ball, and the force of the initial thrust.
As a moving body travels through space, it is transformed in proportion to its velocity and in the direction of its motion. The ratio of motion to velocity contracts the shape of the body and slows its momentum.
The greatest velocity of motion results from superluminous jet-streams which radiate outward from the core of a galaxy. The jet-streams contain particles which appear to be traveling at speeds slightly greater than the speed of light.
The least velocity of motion results from gyrating superclusters of galaxies which fluctuate on the order of 10 to-the-minus 2 cycles per second, with a corresponding wavelength of about 1 million kilometers. Molecules which reach low temperatures approaching absolute zero travel at correspondingly low velocities.
Acceleration or deceleration is the rate of increase or decrease of energy or momentum.
The rate of acceleration or deceleration of an event is proportional to any force acting on it, and in the direction of that force.
As the Earth travels around the Sun, it speeds up as it moves nearer the Sun, and slows down as it moves farther away.
The faster the rate of acceleration of an event, the shorter the time interval between each change of state. The slower the rate of acceleration, the longer the time interval.
The rate of acceleration or deceleration of an event is the absolute time in which the event occurs.
The observed rate of acceleration or deceleration of an event is affected by the time rate of change of the event in relation to the fixed or moving position of the observer.
Looking at these stars suddenly dwarfed my own troubles and all the gravities of terrestrial life. I thought of their unfathomable distance, and the slow inevitable drift of their movements out of the unknown past into the unknown future. – H. G. Wells