Is there an end to the Universe? Is "time" a dimension

Think of time as change we all live in one instance. but atoms spin and things move around, there is no law of nature that says we cant rearange atoms to be like they were 100mill years ago, but it would be very difficult to do so.:) entropy rules. and we all live in different change zones or {time} the closer to a gravity well you are the slower time moves for you. so there is no time "now" other wise you could not see the people on planes who are in a diff change zone than you. their atoms are changing faster than yours.
same goes for speed change slows when your atoms are going fast due to them picking up more mass. but a ship circling the earth at close to the speed of light would still be visable. but it would be in a dramatic diff time or change zone :)