When it comes to the entire cosmos, we humans are incredibly small and insignificant. But that's precisely why we need to take ourselves into account when thinking about the Universe. Find out why.

Observers are, of course, vital in physics: we test our theories by comparing them to our observations. But in cosmology, as Jim Hartle explains, we could be one of many possible observers in the Universe and knowing which one we are is vital in testing our theories.

To celebrate the release of more English translations of Einstein's papers, we revisit one of his previously unknown models of the Universe.

Bob Wald tells us why probabilities are important in cosmology.

There are many theories in particle physics that cannot be tested in experiments. Does this make it unscientific? This debate, featuring one of our favourite theoretical physicists, David Tong, explores the question.

Is cosmology a science or a branch of philosophy? Mathematician and astronomer Bernard Carr gives some answers.

What gives an equation the right to call itself a law?

In this podcast George Ellis explains why the study of the cosmos poses some deep philosophical questions.

Why (some) physicists want to modify Einstein's general theory of relativity.