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.
Everyone knows what time is. We can practically feel it ticking away,
marching on in the same direction with horrifying regularity. Time has
enslaved the Western world and become our most precious commodity. Turn it
over to the physicists however, and it begins to
morph, twist and even crumble away. So what is
This podcast featuring Paul Davies, a theoretical physicist and cosmologist at Arizona State University and Director of BEYOND: Centre for Fundamental Concepts in Science, explores this difficult question and accompanies our What is time article.
You may have heard of quantum theory and you probably know what a field is. But what is quantum field theory? This article traces the development of quantum electrodynamics in the first half of the 20th century. Hair raising difficulties, heroic struggle and illustrious characters — this story has it all!
This is the last article in a four-part series exploring quantum electrodynamics. After a breakthrough that tamed QED in theory, the stick-like drawings known as Feynman diagrams, policed by a young Freeman Dyson, made the theory useable.
In February this year we were lucky enough to interview
Freeman Dyson at the Institute for Advanced Studies in
Princeton, USA. Dyson is now 89 and still does physics every day in
his first floor office at the Institute.
Here is an edited version of our interview that we hope conveys his
generous nature, wit and intellect.
Space is the stage on which physics happens. It's unaffected by what happens in it and it would still be there if everything in it disappeared. This is how we learn to think about space at school. But the idea is as novel as it is out-dated.