What makes these two particular efforts so fascinating is that the authors analyse the relationship not through the historian's prism of war, empire, economics and so on, but through language.
The visible light from it was bright enough for George Djorgovski, Mark Metzger and Shri Kulkarni of the California Institute of Technology and their colleagues to analyse, and to demonstrate that it had travelled through a cloud of interstellar gas at least 10 billion light-years from the earth.