freenrg 0 Report post Posted May 13, 2009 You are correct that the fact the synchronisation occurs on Earth is an issue. What you have stumbled across in a round about way is known as the "Twins Paradox". You have also managed to reach the solution to it The paradox is normally explained with spaceshuttles as the effect is more obvious, but planes work just as well.Consider two twins: Laura and Emily. Emily stays on Earth while her twin, Laura, is put in the space shuttle and fired off into the distant reaches of space. Because of the speed of the shuttle, Emily observes time as proceeding more slowly in the space shuttle than on Earth. So, when Laura returns she will be younger than Emily.However, to Laura the space shuttle is an inertial reference frame. As the Earth moves relative to her, she thinks Emily is ageing slower than her. When she returns, Laura thinks Emily is younger. So, who's right?Laura's space shuttle has had to accelerate relative to the Earth to take off. Then again as it turns round to return. However, Emily has remained fairly inertial throughout the entire process. Laura's frame of reference (the space ship) therefore cannot be considered inertial, and her calculations are incorrect. Emily's are right, and Laura is the younger of the twins when she gets back.The same can be said of planes. As they need to accelerate away from the Earth, and then back towards it, they can't be considered inertial.I understand it now!ThanksThis is great. Share this post Link to post Share on other sites
