Are there parallel universes? Universes in which, rather than reading this article, you are still asleep; in which you are happier, unhappier, richer, poorer, or even dead? The answer is "possibly". It's a controversial claim but one that has won more and more followers over the last few decades.
We reflect on the late John Conway, the thoughts he shared with us over two interviews, and the experience of meeting him as a person and a mathematician.
Find out why scientists trying to build quantum computers might do worse than talk to birds.
Revolutionary laser tools that have changed our lives have won the Nobel prize in physics.
Most of us know what we mean when we say that something has happened. For theoretical physicists, however, this isn't an easy question. Sean Carroll of the California Institute of Technology explains why it's hard to define events and what to do about it.