Einstein's 1918 turning-around hoax: All along, the travelling twin (Jane) observes the sedentary twin's clock to run slow, but during the short turning-around period she imagines herself to be on the surface of a planet and her sedentary brother a long way overhead. While fiercely singing "Divine Einstein" and "Yes we all believe in relativity, relativity, relativity", she concludes that her brother's clocks run fast during the turning-around period, and he ages quickly. So, thanks to Jane's imaginations, the paradox is resolved:
http://www.phys.unsw.edu.au/einsteinlight/jw/module4_twin_paradox.htm
Professor Joe Wolfe: "Jane and Joe are twins. Jane travels in a straight line at a relativistic speed v to some distant location. She then decelerates and returns. Her twin brother Joe stays at home on Earth. The situation is shown in the diagram, which is not to scale. Joe observes that Jane's on-board clocks (including her biological one), which run at Jane's proper time, run slowly on both outbound and return leg. He therefore concludes that she will be younger than he will be when she returns. On the outward leg, Jane observes Joe's clock to run slowly, and she observes that it ticks slowly on the return run. So will Jane conclude that Joe will have aged less? And if she does, who is correct? According to the proponents of the paradox, there is a symmetry between the two observers, so, just plugging in the equations of relativity, each will predict that the other is younger. This cannot be simultaneously true for both so, if the argument is correct, relativity is wrong. (...) If Jane cannot look out of the ship, her sensations and measurements during the deceleration will be just the same is if her ship were at rest on the surface of a planet and that gravity made things fall towards the floor. The local equivalence of a gravitational field and an accelerating frame is a starting point for Einstein's General Theory of Relativity. One of the consequences of the general theory is that clocks at high gravitational potential run more quickly than those at low potential. (So, for example, very accurate laboratory clocks on Earth run are observed to run faster when their altitude is increased.) In terms of Jane's local frame during the turn around, Joe is a long way overhead and so, according to her, his clocks run fast during that time, and he ages quickly. Further, Joe's 'height' above her depends on how far she has travelled, so his clocks run more quickly during the turn around in a long voyage. This is quite important, because proponents of the twin paradox sometimes argue that, whatever the effect of the turn around, it can be made negligible by making the journey far enough. Not so. The longer the journey, the greater the effect due to GR. (Similarly, in terms of the SR argument above, the longer the journey, the longer it takes for Jane's change of frames to be observed by Joe, and so the bigger effect.) Thus, if Jane applies General Relativity as well as Special Relativity, she concludes that Joe will be older and thus resolves the paradox. It is important to point out, however, that appealing to General Relativity is not necessary to resolve the paradox, as demonstrated above. In order to create the twin paradox, one must assume that Jane has been in a single inertial frame throughout her out-and-back trip. As this assumption is false, there is no paradox."
Needless to say, Joe Wolfe's last few sentences are camouflage. If Jane's imaginations and the respective conclusions are ignored ("appealing to General Relativity is not necessary to resolve the paradox"), the answer to the question asked at the end of the following excerpt is "yes" and Einstein's relativity will have to be rejected as contradictory:
"Joe observes that Jane's on-board clocks (including her biological one), which run at Jane's proper time, run slowly on both outbound and return leg. He therefore concludes that she will be younger than he will be when she returns. On the outward leg, Jane observes Joe's clock to run slowly, and she observes that it ticks slowly on the return run. So will Jane conclude that Joe will have aged less?"
Pentcho Valev