The faster an object’s velocity; the slower time passes. This is called Einstein’s Special Theory of Relativity and has been proven to be true innumerable times by comparing atomic clocks. Perfectly synchronized atomic clocks will show differences if one is placed on a plane. The one that travelled, even at a modest subsonic speed, will show a slower time.
This happens every day in particle accelerators. Sub-atomic particles with lifespans in the nanoseconds can last hundreds, even thousands of times longer when they are travelling close to the speed of light.
It is easy to figure out the time dilation experienced by traveling objects. Divide the velocity of the object by the speed of light and square the results. Subtract the result from one and square root it. The final result will be the amount of slowing of time of the traveling object. For example, if an astronaut on a spaceship left earth at a constant velocity of 90% the speed of light (.9c) to a planet 10 light-years away, his velocity would be 270,000 kps and should be divided by the speed of light (300,000 kps) which comes out to .9. Square it (.9 x .9) = .81. Subtract from one (1 - .81) = .19. Get its square root = .4359. The Time Dilation of the spaceship = .4359, meaning, for the 10 light-year trip, the astronaut only experiences 43.59% of time that people on earth would experience. For the ten light-year trip, the astronaut only experiences the duration of the trip to last 4.359 years, whereas ten years would’ve passed on the earth.
To reiterate, the closer an object approaches the speed of light; the slower time passes for it. It is certainly possible for a spaceship to travel 50,000 light years and only experience 10 years subjective time. Heck, it’s possible for a spaceship to travel across the entire universe of billions of light years and only experience a split second of time, if they are just a trillionth of a percentage below light speed.
That's not the only effect, though. Increased gravity also slows down time, so a clock down at sea level, closer to the center of the Earth, would have a tendency to run slower than one at high altitude, partially canceling out the relativistic effect of motion.
Excellent, just excellent presentation of the facts. You are absolutely correct in your math... thanks for posting a really amazing synopsis of relativity fact.
Excellent! ... And a photon remains in the present of where it was generated, never wavering into the future or into the past as a photon, thus it crosses the universe in no time lapse for the photon. Could we then say that the photon is ‘carrying’ a bit of time in itself thus it is in ‘cavitation’ to the universe around it?
Its not ‘velocity,’ but acceleration that dilates time. Thus for an object in free fall time advances more rapidly, while for an accelerated object time passes slower.