Most scientists think that everything that we know and experience began with the Big Bang, 14 billion years ago. But how can ...

Once we discovered that the Universe was expanding, the next scientific step was to determine what the rate of expansion was. Despite the fact that it's been more than 80 years, we still don't ...

Our entire cosmic history is theoretically well-understood, but only because we understand the theory of gravitation that underlies it, and because we know the Universe's present expansion rate ...

How do we know the universe is expanding? Why can’t there be an alternative explanation, say that all atoms are shrinking? Richard Swifte, Darmstadt, Germany We can’t be sure that the universe ...