Philip Ball looks at how a little-known paper by Niels Bohr demonstrates the turmoil in physics on the brink of quantum ...

This model was a centrepiece of what has become known as the old quantum theory, which itself was the product of a realization at the turn of the twentieth century that the precepts of classical ...

Quantum field theory marries the ideas of other quantum theories to depict all particles as “excitations” that arise in underlying fields. The British physicist Paul Dirac started the ball ...

Just as it would be impossible to make sense of modern biology without Charles Darwin’s theory of evolution, our fundamental understanding of the physical world is now rooted in quantum principles.