The other day there was Nova special program on Star Trek. The show covered subjects like space travel and limitations to speed due to massive energy requirement. All was very interesting and seemed like plausible explanation for why space travel would be almost impossible for humans. Then the scientists in the show made some statements that quite didn't make sense and in fact was self contradictory.
It was time dilation.
Basically what they stated is that if someone travels near speed of light what seemed like a month of travel for the person in the spaceship would return to Earth thousands of years later at Earth time. Ok. Now there are two point of references in this scenario. Person on the Earth and person on the spaceship. Mathematically I suppose this was proved and each point of reference would see the passage of time according to the statement. Assuming the mathematics is correct. I mean, if the mathematics is universal truth independent of human existence.
The problem is this.
Scientists have measured the distance of various stars in the universe from less than 10 to more than 100,000 light years away. Let's suppose humans have built a ship to travel to a place 2 light years away at speed of light. After launch the person on the earth would assume the ship have arrived at the destination after two years. And after another two years on the earth the ship will return. If that does not hold true then the actual measurement of the distance would be false. Wouldn't it? Or should scientists assume the ship will not return for thousands of years and forget about the whole launch.
From the point of view on the spaceship the whole travel could seem like few days instead of two years. Sort of like being in a live slow motion without being in the cryofreeze. It's not that the person on the space ship took less time or the people on Earth aged faster. As an object approaches speed of light the passage of time for that object approaches zero.
What that means is that if someone travels at speed of light the only time passed for that person is the time it took to accelerate into speed of light and decelerate to stop from speed of light. Of course all the while from Earth's point of view the spaceship is traveling and aging. From the spaceship point of view the crew would have amnesia of the time it took to travel from point A to point B once it achieved speed of light. It would be instantaneous from spaceship point of reference since no time would have passed in that frame of reference.
So what does that mean? It means that at speed of light you can travel instantaneously from point A to point B except that everyone outside of your point of reference would not stop time with you.
It also means that two different frame of reference may have two different speed of time without contradicting physical laws. That means each individual on Earth can age at different speed by virtue of having different frame of reference.
You can slow down the speed at which you age.
