The heady promise of tiny machines

The 2016 Nobel Prize in chemistry has been awarded for the design and synthesis of the world's smallest machines. The work has overtones of science fiction, but holds huge promise in fields as diverse as medicine, materials and energy. This is especially true of efforts to develop nano-scale machines (1,000 times smaller than the width of a human hair), which are always destined to remain tiny however big our ambitions for them grow. It's difficult to trace the development of molecular machines to one person or scientific step. But a 1959 lecture by the celebrated physicist Richard Feynman is as good a point as any.