Philosophy of cosmology

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

If you like to have your mind blown cosmology is a great field to go into. But is it science?

George Ellis explains why the study of the cosmos poses some very deep questions.

How big is the Universe? Where did it come from and where is it going? Why is it the way it is? These are just some of the questions cosmologists study.

David Sloan calculates how likely it is that our Universe exists. He explains to us how, and why the answer can help shape our theories of physics.

In this podcast we talk to Max Tegmark about his hypothesis that the Universe we live in is a mathematical structure.

Some of the things I overheard at Stephen Hawking's 70th birthday conference did make me wonder whether I hadn't got the wrong building and stumbled in on a sci-fi convention. "The state of the multiverse". "The Universe is simple but strange". "The future for intelligent life is potentially infinite". And — excuse me — "the Big Bang was just the decay of our parent vacuum"?!

This is the first part of the lecture given by Astronomer Royal Martin Rees at Stephen Hawking's birthday symposium.

This is the second part of the lecture given by Astronomer Royal Martin Rees at Stephen Hawking's birthday symposium.

This is an excerpt from Stephen Hawking's address to his 70th birthday symposium which took place on 8th January 2011 in Cambridge.

What's the mysterious stuff that makes up 70% of our Universe?

With online socialising and alternative realities like Second Life it may seem as if reality has become a whole lot bigger over the last few years. In one branch of theoretical physics, though, things seem to be going the other way. String theorists have been developing the idea that the space and time we inhabit, including ourselves, might be nothing more than an illusion, a hologram conjured up by a reality which lacks a crucial feature of the world as we perceive it: the third dimension. Plus talks to Juan Maldacena to find out more.