re is maintained with energy supplied by dark matter particles annihilating in the degenerate interior. The sun glows faintly in the infrared On the hard surface of Earth, the temperature is about 1 degree above absolute zero. The atmosphere is gone. Every trace of the once-flourishing biosphere has vanished. Here and there, the surface has been cratered by increasingly infrequent asteroid and comet impact Beyond the solar system, the sky contains a surprising number of bright red stars, which merge into an impressive glow in the direction of the gas free and unobscured center of the galaxy". Such is the current view on the future of our galaxy, pieced together, as the authors note, from our present understanding of physics and astronomy. However, it is important to realize that our knowledge of science changes over time. Fifty years ago, for example, the theory of the future of our galaxy might have looked very different from this one. To quote the authors: "Who knows what processes might alter the course of our distant future."...
