Let me take you down, cos we're going to ... quantum fields 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!
Taming QEDThis is the third article in our four-part series exploring quantum electrodynamics. After struggling with a theory plagued by unwieldy infinities an ingenious trick put QED back on track.
Quantum picturesThis 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.
Operas, revolutions and nature's tricks: a conversation with Freeman DysonIn 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.
Cognition, brains and Riemann Are number, space and time features of the outside world or a result of the brain circuitry we have developed to live in it? Some interesting parallels between modern neuroscience and the mathematics of 19th century mathematician Bernard Riemann.
Twins move within reachAgreeing to pay £50,000 for something worth £2 wouldn't win you any haggling competitions. In mathematics, however, a similar result can bring you international acclaim. This is the case with recent progress towards the famous twin prime conjecture.
Folding the future: From origami to engineeringRemember how hard it was to fold maps? Mathematicians have struggled with map folding problems for ages but a recent insight suggests there might be another way to approach them, making an unlikely connection between combinatorics, origami and engineering.
Why you shouldn't use a toss for overtimeIn soccer a coin toss is used to decide who goes first in a penalty shootout and similarly in American football a coin decides who plays offence in overtime. But is this really fair? This article explores an alternative.
Ripping apart EinsteinCutting the threads of the spacetime fabric and reinstating the aether could lead to a theory of quantum gravity.
Melting spacetimeTo understand how spacetime might have emerged in the early cosmos we need to heat up the equations, and thaw the space and time dimensions.
What is space?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.
How to add up quicklyThe number pi can be expressed beautifully in terms of infinite sums. For practical purposes though, these sums are rather disappointing: they converge slowly, so you need to sum a large number of terms to get accurate estimates of pi. Here's a clever way to make them converge faster.
