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Hello, until the end of the 19th century, the phenomenon of electricity was very poorly understood.

But in a few generations the world was transformed, first by electric power and then by the electronic revolution which resulted in invention of computer technology.

The transformation was brought about by a new understanding of not just of electricity but of the materials through which it

can travel. All substances on the planet can be divided into categories according to

their ability to conduct electricity. Those that can like metals are called conductors. Those that don't are known as insulators.

But there are also semiconductors whose discovery has made possible the invention of the transistor and the solar cell.

And finally, there are superconductors whose unique

properties have a range of useful applications from medical imaging to

particle accelerators. With me to discuss electrical conduction,

semiconductors and superconductors, of Frank Close, Professor of Physics at the

University of Oxford, Jenny Nelson, Professor of Physics at Imperial College London, and Leslie

Cohen, Professor of Solid State Physics also of Imperial College London.

Frank Close, when did scientists begin to tackle and understand the phenomenon of electricity?

Well, understanding, of course, is relatively recent, but the idea... phenomenon of

the electricity.

Well, understanding of course it's relatively recent, but the idea of the

phenomenon has been around for two and a half thousand years or more.

I mean, the simplest way probably of making electricity right here and now is brush your hair very violently and if you do

that in a darkened room you might even make sparks fly. And that sort of phenomenon was known

to the ancient Greeks. They knew that if you rubbed a form of resin called amber, it would have these mysterious

...