This diagram depicts the major milestones in the evolution of the Universe since the Big Bang, about 13.8 billion years ago. It is not to scale. The Universe was in a neutral state at 400 thousand ...

Everything has to end eventually – but does that include the universe itself? And if so, how? And when? It might be hard to imagine a catastrophe big enough to affect the entirety of existence, but ...

What makes the dark universe brighter—at least in certain places—is the light of the stars. But they were not present from the beginning. Once, there must have been a time when not a single star shone ...