German castle, we follow the scientific surprises as DNA beat out protein, the more logical candidate, as the stuff of the gene. Joshua Lederberg pays tribute to the work of Oswald Avery, the Canadian-born scientist who first proved it was DNA and the impact this had on his own landmark discovery that bacteria have sex, ie exchange genetic material. Two sets of clues led to the discovery of the do…

An optical transistor that uses one laser beam to control another could form the heart of a future generation of ultrafast light-based computers

Shootings in deprived areas of Chicago and Baltimore have plummeted thanks to a programme that treats violence as if it is an infectious disease

Astronomers have found the best evidence yet of an elusive intermediate-mass black hole