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

Find out with Martin Rees

How do we know how many people have got it?

Scientists crack black holes' balancing act

Can a scientific approach to risk in finance avoid the next financial crisis?

A statistical test applied to the election results

Will the Ashes result depend on the weather?

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.

Two of the most fundamental questions asked by people are how life emerged on the Earth, and whether we are alone in the cosmos. These deeply important questions form the core of a new kind of science, one that recently has been rapidly gathering momentum: astrobiology. Lewis Dartnell explains.

Which drugs should be available on the NHS?

Chess versus sumo

On May 19 2009 the Space Shuttle Atlantis released the Hubble Space Telescope back into orbit after a hugely successful servicing mission. To mark the occasion, Mario Livio, one of the scientists involved in the mission and intimately acquainted with Hubble, takes stock of its scientific legacy.