Picture an inflating balloon. The outward expansion of the balloon represents a 2-dimensional universe undergoing the passage of time. As the 2-dimensional universe expands outward, it carries all of these bodies along with it. The movement of these bodies outward at a slower rate represents the decrease in the rate of aging that the bodies undergo. The more massive the body, the more slowly it ages.
All objects possess mass.
As a result, the object in motion is carried outward at a slower rate, and in effect ages more slowly. We can conclude that the faster the rate at which an object travels, the more slowly it ages. With the recent mention of Einstein in mind, I am posting a message that was inspired by the discussions on time found near the very beginning of the Discussion Forum - a message that puts into consideration the very nature of time itself. Relativity says that objects in motion age more slowly. Of course the effect is only noticable when the object is moving at near-light speed.