Hi people! (Sorry for my poor english). I found everywhere that twin paradox need aceleration to explain it. Let me change the twin paradox a little: Suppouse that in Earth and before the traveller twin start his trip, you take two photos with old Polaroid camera, one to each twin. As we remember, those kinds of photos become older, degrading its colours, a little fast. Some day the traveller twin left his own photo pasted in one window of his house looking outward and takes the Polaroid camera and start a trip in his capable of reach near light speed spaceship. And he goes to the left respect to Earth. Goes to left far enough to be able to stop and start to travel to right in the direction to Earth in a way he could pass Earth going right at near speed of light without any aceleration. When pass Earth he points his Polaroid to his house and take a Polaroid photo of his Polaroid photo still on Earth and pasting it looking outwards in one of his capable of reach near speed of light spaceship window. Time later he pass another spaceship coming at the same absolute speed (in a frame at rest respect the non traveller twin) but with opposite direction, to left, and with no aceleration, and the captain of this spaceship take a Polaroid photo of his Polaroid photo and paste it looking outwards in one of his spaceship window. Time later this second spaceship pass Earth without change its speed, so no aceleration here neither, and the non traveller twin take a Polaroid photo of the Polaroid photo of the Polaroid photo of the Polaroid photo taked time ago in Earth. Then he compared his old Polaroid photo of him whith this new Polaroid Photo of his twin. Having both Polaroids photos images of them in younger ages, is this new Polaroid photo less degraded colours than the old Polaroid photo no matter none Polaroids photos suffered any aceleration never? If all motions are relative, why not the opposite? I hope I could explain my idea even with my poor english. Where I´m wrong if I say that yes, the new Polaroid have less degraded colours than the old one? Thanks! Luis.