The real twin paradox.
in [Relativity]
|
From: colp on 21 Nov 2007 18:57 On Nov 22, 10:14 am, colp <c...(a)solder.ath.cx> wrote: <snip> Double post. Sorry.
From: bz on 21 Nov 2007 19:55 colp <colp(a)solder.ath.cx> wrote in news:1a3bb0bf-fe3f-4080-9837-065d512490c9(a)s8g2000prg.googlegroups.com: > I didn't forget. The issue isn't critical in regard to the paradox, > that's all. > >> Perhaps each clock digitally >> encodes the date and time and transmits it by radio, every second. This >> is cheaper than having an infinite set of observers for each inertial >> frame of reference so that the clocks can be checked by a nearby >> observer co-moving with the other ships frame of reference. > > O.K. > >> >> In any case, While traveling away from each other the signals from the >> other ship are Doppler shifted downward in frequency and the time hacks >> come further apart than once per second. When traveling toward each >> other, the signal from the other ship is Doppler shifted upward in >> frequency and the time ticks arrive faster than once per second. > > Technically I think it's called red & blue shift rather than Doppler, > which > refers to sound rather electromatic radiation. Tell that to the traffic cop that gave me a ticket. He clocked me using a Doppler radar. :) Actually, the term is freely used to describe the effect. There are TWO different Doppler shifts. Actually three. 1) classical Doppler shift (newtonian physics) 2) relativistic Doppler shift 3) transverse Doppler shift ..... > > Redshift/blueshift shift would be a real issue, but it is a different > one to > Lorentz-Fitzgerald time dilation. Redshift/blueshift is proportional > to > relative velocity, but time dilation has a non-linear relationship to > the > absolute value of the relative velocity. > > http://en.wikipedia.org/wiki/Time_dilation If I remember correctly, the relativistic Doppler shift takes into account the classical Doppler shift AND the time dilation. In classical Doppler, the shift drops to zero when the path of the wave is perpendicular to the direction of travel. The transverse Doppler effect is NOT zero at that point due to relativisitic effects. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+spr(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: bz on 21 Nov 2007 20:33 "Sue..." <suzysewnshow(a)yahoo.com.au> wrote in news:75645b9d-5e0d-4d6d-8793-6a916df243dd(a)l1g2000hsa.googlegroups.com: > On Nov 21, 1:29 pm, bz <bz+...(a)ch100-5.chem.lsu.edu> wrote: >> "Sue..." <suzysewns...(a)yahoo.com.au> wrote >> innews:a99fa604-6121-47d8-96a8-90c3c19d2e8d(a)l1g2000hsa.googlegroups.com: >> >> > normal clocks that are not responsive to motion >> > through a dielectric shouldn't change rate. >> >> I tried to buy a 'normal clock' at the clock store but they told me >> they are no longer made. They used to be made in Newton's days, but now >> EVERYTHING that is made of charged particles responds to motion through >> space, which is a dielectric medium. Maxwell managed to change the laws >> of physics with his equations. > > Did you try to buy a light-clock specifically designed to > respond to motion through media? No, I wanted a 'normal clock', one that ran at the same rate, no matter what its speed was. > If the clock store had one > I think you would find most of the clocks you have are > "normal" when you blow hydrogen gas at a significant fraction > of c toward or past their cases. But I am not blowing hydrogen past the case, the case is moving THROUGH the hydrogen. But it doesn't. In your case, the clock having hydrogen blown by it and my clock are at rest wrt each other. In the second case, the test clock moves through the hydrogen which is at rest wrt my clock. In the second case, the test clock loses ticks (when it gets back from its trip it has accumulated less ticks than my stay at home clock). It does this no matter HOW big or well made the case is. Electrostatic shielding and magnetic shielding doesn't make any difference. > > The gas moving between the light-clock's mirrors will cause it > to slow however. Not a light clock. Not a heavy clock. A special ultra stable quartz crystal clock, temperature stabilized. It uses three crystals, each perpendicular to the others. But it still isn't a 'Sue normal clock' because it loses ticks. > >> >> And the neutronium clocks are too heavy to carry around. >> >> So, let me borrow your 'normal clock' pleeeeze. I will gladly return it >> just as soon as my twin brings it back from his trip to the Andromeda >> Galaxy. > > "normal" clocks are usually inertial mechanisms. Are you disputing > this statement with your suggestion that a light-clock should behave > the same way as an inertial clock ? I am not talking about light clocks at all. I still don't know about them. KS keeps telling me that the first photons miss the mirrors. KS, HW and Sue keep telling me that "normal clocks" don't lose ticks, no matter how far and fast they go. I don't know who to believe, KS, HW and Sue or the evidence. Maybe the contradiction between the evidence and what KS and Sue say is only apparent. I am talking about 'normal clocks' such as a quartz crystal clock. Do you agree that that is an inertial clock? > > > <<A Lorentz transformation or any other coordinate > transformation will convert electric or magnetic > fields into mixtures of electric and magnetic fields, > but no transformation mixes them with the > gravitational field. >> > http://www.aip.org/pt/vol-58/iss-11/p31.html > > > If you can, then you will be demonstrating that > General Relativity is unnecessay and you'll have > some evidence of an inertial ether to support your > argument. I would love to see data that falsifies GR, but I don't expect to see it soon or here. But that is not my goal at the moment. My goal is to find a "normal clock" that will be unaffected by traveling at relativistic velocities wrt a stay-at-home test clock. Tell me where I can find one, pleeeese. >> And the neutronium clocks are too heavy to carry around. >> >> So, let me borrow your 'normal clock' pleeeeze. I will gladly return it >> just as soon as my twin brings it back from his trip to the Andromeda >> Galaxy. > > I'll trade you a normal clock for a light-clock. Oh, light clocks are not difficult to build. You can take a fiber optic transceiver and a mirror and a bit of electronics. Do a little optical impedance matching to free space and set up your mirror at a convenient distance. Set the electronics so that every time a tick is received, a new tick is launched. Press the little 'starter' button. You have a light clock. Any high school kid can build one. The real trick is to build a 'normal clock' that ACTS like sue says a 'normal clock' should act. > You might get a good deal on this one but you'll > have to supply your own launch vehicle and figure out > how to expose it to moving ism. > > http://funphysics.jpl.nasa.gov/technical/grp/sumo.html > Show me the data. Did it run slow, as predicted by SR and GR or did it maintain a constant rate as per Sue, KS, HW??? It was supposed to launch in 2006. This is almost 2008. The web page was last updated in 2004. Show me the data. -- bz please pardon my infinite ignorance, the set-of-things-I-do-not-know is an infinite set. bz+spr(a)ch100-5.chem.lsu.edu remove ch100-5 to avoid spam trap
From: colp on 21 Nov 2007 21:27 On Nov 22, 5:48 am, "Josef Matz" <josefm...(a)arcor.de> wrote: <snip> > Hello Dirk > > If you could mathematically demonstrate that the time delays of the > symmetric clock A as viewed by B can be > compensated somehow you have solved the paradox ! > > Would you tell us idiots how this runs in SR ? A solution could include an argument from general relativity as well, since the twins must spend time in non-inertial frames in order to accelearate/decelerate and turn around. I don't think it would solve the paradox though because the dilation effects can be increased arbitrarily by extending the amount of time spent in inertial frames.
From: Cosmik de Bris on 21 Nov 2007 22:16
colp wrote: > On Nov 22, 5:48 am, "Josef Matz" <josefm...(a)arcor.de> wrote: > <snip> >> Hello Dirk >> >> If you could mathematically demonstrate that the time delays of the >> symmetric clock A as viewed by B can be >> compensated somehow you have solved the paradox ! >> >> Would you tell us idiots how this runs in SR ? > > A solution could include an argument from general relativity as well, > since the twins must spend time in non-inertial frames in order to > accelearate/decelerate and turn around. I don't think it would solve > the paradox though because the dilation effects can be increased > arbitrarily by extending the amount of time spent in inertial frames. General relativity is not required and does not help in this case. It is possible to set up the "twin" scenario with triplets where no turn around is required. This involves a third person to carry the clock reading from the outbound twin back to the earthbound twin. -- Posted via a free Usenet account from http://www.teranews.com |