A trip to the end of the universe and the twin paradox
arXiv:physics/0612126
Abstract
In principle, the twin paradox offers the possibility to go on a trip to the center of our galaxy or even to the end of our universe within life time. In order to be a most comfortable journey the voyaging twin accelerates with Earth's gravity. We developed some Java applets to visualize what both twins could really measure, namely time signals and light coming from the surrounding sky.
There are two Java applets which can be downloaded from http://www.tat.physik.uni-tuebingen.de/~tmueller/twins/