I guess I should have put "stationary" in quotes. Bill Potts, CMS Roseville, CA http://metric1.org [SI Navigator]
> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On > Behalf Of Joseph B. Reid > Sent: Friday, June 14, 2002 11:28 > To: U.S. Metric Association > Subject: [USMA:20401] Re: Fwd: Re: Yesterday's Star Trek on BBC 2 > > > I think that Bill Potts in USMA 20399 has made the wrong assumption that A > is stationary and that B is moving. That is contrary to the basic > postulate of relativity that there is no such condition as stationary; > there is only motion relative to each other. > > >John: > > > >I believe you have that one wrong. The slowing of the local clock as one > >approaches the speed of light is independent of the direction of travel. > > > >The only problem with respect to the twins is that a really > enormous amount > >of energy would be required to carry out the experiment. However, the > >traveling twin would indeed be younger than the stay-at-home one. > > > >The twin traveling close to the speed of light would not, of course, be > >aware of the slowing of the clock. That slowing is only as > "viewed" from a > >stationary vantage point. > > > >Bill Potts, CMS > >Roseville, CA > >http://metric1.org [SI Navigator] > > > >> -----Original Message----- > >> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On > >> Behalf Of kilopascal > >> Sent: Thursday, June 13, 2002 21:03 > >> To: U.S. Metric Association > >> Subject: [USMA:20398] Re: Fwd: Re: Yesterday's Startrek on BBC 2 > >> > >> > >> 2002-06-13 > >> > >> This reminds me of the common belief that if out of a pair of > >> twins, one who > >> travels in space and another who remains on earth, the > returning traveller > >> will find his twin who remained behind older looking. This is > >> known as the > >> twin paradox. But, as we know, nature abhors paradoxes, so the way the > >> SCI-FI writers have presented it is wrong. > >> > >> As Joe pointed out, the observer (Twin remaining on Earth) (A) > >> will observe > >> his twin in space (B) ageing less as his clock is running slower > >> as he moves > >> away at the speed of light. The common belief is that when B > returns to > >> Earth, he is noticeably younger. The truth is, that as the ship turns > >> around and moves back towards the earth at the speed of light, > >> the opposite > >> occurs. B's clock now appears to move faster than on earth and B's age > >> catches up to that of A on the Earth. When B steps off the ship, > >> he is the > >> same age as his brother. The only difference will be the normal > >> ageing that > >> took place because the trip would have consumed some time. > Thus time is > >> conserved and nature remains in balance. > >> > >> John > >> > >> > >> > >> > >> > >> > >> ----- Original Message ----- > >> From: "Joseph B. Reid" <[EMAIL PROTECTED]> > >> To: "U.S. Metric Association" <[EMAIL PROTECTED]> > >> Sent: Thursday, 2002-06-13 20:57 > >> Subject: [USMA:20396] Re: Fwd: Re: Yesterday's Startrek on BBC 2 > >> > >> > >> > 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 > >> > > >> > > >> > > Joseph B.Reid > 17 Glebe Road West > Toronto M5P 1C8 Tel. 416 486-6071 >
