Although electricity has been known for several hundred years, it was only in the early twentieth century that physicists first satisfactorily explained the phenomenon.

It allows researchers to unravel decision-making strategies, and even to establish why certain types of behaviour emerge.

Melvyn Bragg and his guests discuss the development of the microscope, an instrument which has revolutionised our knowledge of the world and the organisms that inhabit it

Melvyn Bragg and his guests discuss Catastrophism, the idea that natural disasters have had a significant influence in moulding the Earth's geological features

Photosynthesis arose very early in evolutionary history and has been a crucial driver of life on Earth.

Melvyn Bragg and his guests discuss the evolution and role of Circadian Rhythms, the so-called body clock that influences an organism's daily cycle of physical, behavioural and mental changes.

Melvyn Bragg and guests discuss the neutron, one of the particles found in an atom's nucleus.

Melvyn Bragg and guests discuss the impact of the eruption of Mt Tambora, in 1815, on the Indonesian island of Sambawa.

It is said he noticed some blue-green penicillium mould on an uncovered petri dish at his hospital laboratory, and that this mould had inhibited bacterial growth around it.

Melvyn Bragg and guests discuss the devastating mass extinctions of the Late Devonian Period, roughly 370 million years ago, when around 70 percent of species disappeared.