After some time I post again. I'd like to ask something about theory of relativity. I think you know about this experiment with two clocks. In the beginning they were synchronized. Then one was left on the place and the other one flew around the Earth. After they brought the clocks together again, they found out that the second one had been running slower. Was the time dilation caused only by the different gravity affecting them or also by the motion?
Both have been measured experimentally by this method, the biggest difference is in the special relativity effect rather than the general though.
OK... When two clocks are moving towards each other, do they see each other's time run faster than their own?
No slower. When two clocks are moving towards each other, they see each other's time run slower than their own. Same as would happen if the are moving away from each other.
Oh boy. I predict a shit-storm of cranky replies here. Can't wait! *rubs hands in gleeful anticipation*
I thought relativity suggests this, but it didn't quite make sense to me. Another example: Two clocks are synchronized in the reference frame they are at rest in, then start to move in oposite directions, after each one registers particular time (say 1 hour) they stop and begin to move towards each other. In the end they stop at the same distance they were beginning at. Now they should display the same time, shouldn't they? Is it the non-linear motion that caused the clock in the first experiment to display lower time? If so, how can it be calculated?
Two days and no reply? Why? I have searched for the answer before and didn't find it. I more or less understand time dilation when the motion is linear, but in this experiment it is not and in addition I think that linear motion wouldn't cause the clocks to display different times in this way. I can post a more detailed explanation of this if you want. I am possibly wrong, please correct me if so. At least a link to some info would be appreciated. Thanks in advance.
In the end they display the same time. It can be calculated using the Lorentz transform: the paths are symmetric in the original rest frame so the spacetime intervals are the same so they display the same time. All SR predictions are calculated using the Lorentz transform. -Dale
Yes that is correct if however one stayed stationary and the other did all the travelling, the one which made the velocity changes would have age less in both the outward journey and inward journey according to the other stationary clock, therefor the travelling clock will have aged less just the same as circling the earth. Do you see the difference and thus how there is no paradox as some would have you believe?
It was caused by both. The gravitational effect causes clocks at altitude to run faster than clocks on the ground. But the motion effect causes clocks on a moving plane to run slower than clocks on the stationary ground. The dominant effect in this experiment, contrary to what imaplanck said, is the gravitational effect. Overall, the clocks on the plane ran faster than clocks on the ground.
There is no gravitational effect on the clock or the satellite’s radio-signal. A satellite's radio-signal's wave-lengths is elongated on its way, and this is caused by entropy-displacement (that both Planck and Hubble have observed but misinterpreted). This wave-length displacement has been (is) measured as frequency-shift and is misinterpreted time-shift. Pound-Rebka's well known Mossbauer-experiment does not verify a gravitational time-shift. They said in their scientific paper (1960) that they didn’t understand how they should interpret their experiment's results. They made a statistical interpretation and decided that the wave-elongations that were larger than the mean-value were red-shifted and the shorter elongations were blue-shifted. But all the gamma-signals were redshifted. It is like comparing two dragsters with their mean-value speed, and decide that the faster of them is running forward (red-shifted) and the slower is running backward (blue-shifted). A clock-signal changes frequencies (wavelengths) as a Doppler-effect caused by the moving plane’s speed or/and rotating earth. But the time-dilation hypothesis is wrong. Ingvar, Sweden http://www.theuniphysics.info
Most scientists disagree with you, Ingvar. Have you published your theory in a peer-reviewed journal?
A quick note on the validity of the Hafele-Keating experiment which the opening post mentions. It was shown to be fraudulent in its conclusion. The cesium clocks used in the experiment differed wildly in expected outcome and the results were modified by Hafele and Keating to fit the predicted values. This, of course, means nothing to the phenomena of time-dilation as a whole, however. Because the phenomena has been proven in other ways. It only speaks of the unethical behavior of two scientists who were unable to admit failure due to technical difficulties. The stakes were too large for them, I suppose. Pressure to publish is a terrible thing.
No one has suggested that the experiment produced a totally null result. There have been suggestions that the experiment was not accurate enough to distinguish between Einstein's relativity and Newtonian mechanics. The most cited criticism is AG Kelly's Hafele & Keating Tests; Did They Prove Anything?(1998). All these criticisms simply allege that the Hafele-Keating experiment didn't prove anything either way, and that Hafele and Keating were wrong to say that it did. So assuming that the criticisms of the experiment are correct... then yes, the experiment means nothing. Of course, there are other flying clock experiments to consider. The GPS system, for example: At the time of launch of the first NTS-2 satellite (June 1977), which contained the first Cesium clock to be placed in orbit, there were some who doubted that relativistic effects were real. A frequency synthesizer was built into the satellite clock system so that after launch, if in fact the rate of the clock in its final orbit was that predicted by GR, then the synthesizer could be turned on bringing the clock to the coordinate rate necessary for operation. The atomic clock was first operated for about 20 days to measure its clock rate before turning on the synthesizer. The frequency measured during that interval was +442.5 parts in 1012 faster than clocks on the ground; if left uncorrected this would have resulted in timing errors of about 38,000 nanoseconds per day. The difference between predicted and measured values of the frequency shift was only 3.97 parts in 1012, well within the accuracy capabilities of the orbiting clock. This then gave about a 1% validation of the combined motional and gravitational shifts for a clock at 4.2 earth radii.(General Relativity in the Global Positioning System & NTS-2 GPS Flying Clocks) Full Report The UK National Physics Laboratory is supposed to have done some sort of replication of the Hafele Keating experiment with more accurate clocks in 2005, but I can't find a decent write up.
The real result of the infamous science experiment was that its data was so wildly unsupportive of Special Relativity that it can only be characterized as a null result for proving the theory. In view of the fact that it magnificently failed to prove the theory correct, it can easily be taken to be proof of the theory's lack of legitimacy. Elvis is supposed to have landed his flying saucer on the White House lawn, but I can't find a decent write up.
Do you have any support for this assertion? Or are we supposed to think that if CANGAS says it, it must be true? Please Register or Log in to view the hidden image!.
Umm. No. It just means that the clocks were a bit screwy and the experiment was a bust. The experiment has been performed in various other ways and the predictions have panned out. The GPS was one. There was also a 25th anniversary of H&K with better clocks. My only problem with the affair is that even though the results were shown to be fraudulent (unless Kelly's criticisms are disputed) the experiment is still hailed as a success. Did H&K ever suffer any flack for their behavior? Or was there a grand cover-up? I know I was surprised as hell when I first found out the experiment was faked. But, aside from H&K's unethical behavior, relativity stands as shown in multiple other experiments. Now. If the clocks had worked perfectly, that is no crazy drift, and the results hadn't been as predicted, then it would have been a nail in the coffin. But, that's not how it worked. The clocks were very obviously whacky. Not entirely uncommon, apparently, from those types of atomic clocks.
Perhaps your paradox is removed, but you have created a very deep hole from which there is no salvation -- the matter is 'huis clos". You stated: " Yes that is correct if however one stayed stationary and the other did all the travelling, the one which made the velocity changes would have age less in both the outward journey and inward journey according to the other stationary clock," If your statemnent is true, then you have just removed the "reality" of the equivalent frames of reference postulate" which forms the basis of special relativity theory. The twin in the once accelerated frame of reference has now no justification to consider his motion at rest and the unacclerated twin in motion (what if he had been drugged during the accelerationand was unaware aof his accelerated state?). Your statement negates virtually all of Einstein's train-embankment gedanken experiments. Sorry, you can't have it both ways. I first read your resolution of the "paradox" in a statement by Richard Feynman, so if we use the size of history's giant shoulders as a bench marks illuminating physical truth, your statement has more than adequate support. Geistkiesel
