Madan wrote in USMA 20395: >Few months back, I had an argument with my friend >about the time travel and back to the future concept. > >He said that we will be in same time, if we travel >in the speed of light. >My argument is this >1. even if our spaceship is to move a few meters, > it is going to take atleast few picoseconds. >2. its going to take few minutes to make a sandwich. > >The duration taken to do something is called time. > >Is the concept of 'time' a real thing like distance, >electricity, etc or just a virtual thing. > >Madan
As long as we stay on earth there is no problem. Two persons at the same place can set their clocks to agree. It is when they try to compare the time when they are moving apart that things get complicated. Michelson and Morley tried to find the speed by which we are moving through the ether in which light waves travel. They failed. Einstein theorized that if A and B are moving apart at high speed, A will observe that B's surroundings have shrunk and his clock seems to be running slow to compensate and thus keep the apparent speed of light around B constant. At the same time, B observes that A's surroundings have shrunk and A's clock is running slow. Hence the relativity or reciprocity of the situation. If C is midway between A and B, he will observe that A's clock and B's clock are synchronized. Joseph B.Reid 17 Glebe Road West Toronto M5P 1C8 Tel. 416 486-6071
