Speed keeps ya young

[Robb Phoenix]

If I travel say near light speed to a distant planet and return back to earth, Why the heck do i age less than the people on earth?
What are the other ways to slow/speed time?

[mibn2cweus]

You age less because less time has elapsed in your reference frame compared to the time that had elapsed on Earth. The rate at which physical/mechanical processes take place is slower as you approach the velocity of light when compared to the rate at which these same processes take place on the relatively slowly moving Earth. The slowing of time as you approach the velocity of light is only apparent from an external reference frame that does not share the same accelerated motion.

A large gravity field has the same affect of slowing time as witnessed from an external observer not subject to the same gravity. To an external observer watching an object approaching the event horizon of a black hole, the objects progress toward the black hole would appear to slow down, the wavelengths of light emitted or reflected by the doomed object would stretch toward the infrared while the lights intensity would fade to black at the instant its apparent motion ceased. For an observer experiencing this journey into the event horizon, looking back from whence he came he would observe an acceleration of events in the universe he was leaving concluding with the end of time for both it and himself.

[Robb Phoenix]

Why has less time elapsed on my refrence frame? We dont travel above light speed so we dont violate the constant speed of light (leading to us experiencing time slower compared to external reference).
The external observer sees objects falling towards the black hole because light loses energy and takes time to escape the gravitational speed, this doesnt mean that things are actually taking place at that rate, you fall into singularity in ard 7 sec (assuming wormhles dont exist).So how would he able to see the future?

[mibn2cweus]

No one in any reference frame is privileged to experience or observe the future. The difference between different reference frames is in the rate of the passage of time demanded by the constant velocity of light. The energy of photons as measured in different reference frames in relative motion does not alter their velocity in either reference frame.

In the imaginary reference frame of a photon the universe is a singularity having neither dimensions of length nor time.

At the event horizon of a black hole you would not actually be able to see the end of time of the universe elapse as you would be frozen in time for the duration, assuming you could possibly remain in any condition to observe anything.

If my attempts to explain the observations made in a reference frame traveling at the velocity of light or within the gravitational field of an event horizon fail to make any sense there is a very good reason for this. Such a reference frame is impossibly infinite and for any kind of comprehension you'll just have to "do the math"*. Your approach to gaining such a comprehension (if that is humanly possible) should be initially limited to understanding what happens while approaching the velocity of light rather than trying to work your way back from the velocity of light to make comparisons.

*The maths involved are relatively easy and although within most peoples potential abilities not entirely necessary if you can visualize a trend and follow it to its logical conclusion. Just remember that time and distance are not directly interchangable where there is relative motion (of a difference in gravity) between two observers.

[mibn2cweus]

. . . should read "(or a difference in gravity)