How does it spread?

Adding weight helps Earth dodge killer asteroids

If you're worried that a mathematics degree might limit your career options, then there couldn't be a better person to talk to than Steve Hewson. Find out how his varied career has taken him from the lofty heights of theoretical physics, via the trading floor of a major investment bank, into the maths classroom, and has also seen him writing his very own maths book. This podcast accompanies the career interview from issue 50 of Plus.

In our online poll to find out what Plus readers would most like to know about the Universe, you told us that you'd like to find out what happened before the Big Bang. We took the question to the renowned cosmologist John D. Barrow and here is his answer. The Universe is an infinitely self-perpetuating foam of bubbles, it seems. This podcast accompanies the article What happened before the Big Bang?.

Did the Big Bang mark the beginning of time? Not if we live in a bubble multiverse!

The Abel Prize 2009 goes to Mikhail Gromov

We talk to Professor Robin Wilson, author of the book Lewis Carroll in numberland, about the mathematical work of the famous author of the Alice books, whose real name was Charles Dodgson.

Why length matters