Einstein reminds me of this very interesting excerpt from Gamow's 'One Two Three...Infinity'. Check it out!
'The slowing down of the speed of time in a moving system has an interesting implication in respect to interstellar travel. Suppose you decided to visit one of the satellites of Sirius, which is at a distance of nine lightr years from the solar system, and use for your trip a rocket ship that can move practically with the speed of light.
It would be natural for you to think that the round trip to Sirius and back would take at least eighteen years, and you would be inclined to take with you a very large food supply. That precaution, however would be absolutely unnecessary if the mechanism of your rocket ship made it possible for you to travel nearly at the speed of light. In fact if you move, for example, at 99.99999999 percent of the speed of light, your wristwatch, your heart, your lungs, your digestion, and your mental processes will be slowed down by a factor of 70000, and the 18 years ( from the point of view of people left on Earth) necessary to cover the distance from Earth to Sirius and back to Earth again, would seem to you as only a few hours.
In fact, starting from the Earth right after breakfast, you will just feel ready for lunch when your ship lands on one of the Airius planets. If you are in hurry and start home right after lunch, you will, in all probability, be back on Earth in time for dinner. But, and here you will get a big surprise if you have forgotten the laws of relativity, you will find on arriving home that your friends and relatives have given you up as lost in interstellar spaces and have eaten 6570 dinners without you!
Because you are travelling at a speed close to that of light, 18 terrestrial years have appeared to you as just one day!'
