The Story of Electricity episode 2 – The Age of Invention: Professor Jim Al-Khalili tells the electrifying story of our quest to master nature’s most mysterious force – electricity. Until fairly recently, electricity was seen as a magical power, but it is now the lifeblood of the modern world and underpins every aspect of our technological advancements.
Without electricity, we would be lost. This series tells of dazzling leaps of imagination and extraordinary experiments – a story of maverick geniuses who used electricity to light our cities, to communicate across the seas and through the air, to create modern industry and to give us the digital revolution.
Just under 200 years ago scientists discovered something profound, that electricity is connected to another of nature’s most fundamental forces – magnetism. In the second episode, Jim discovers how harnessing the link between magnetism and electricity would completely transform the world, allowing us to generate a seemingly limitless amount of electric power which we could utilise to drive machines, communicate across continents and light our homes. This is the story of how scientists and engineers unlocked the nature of electricity in an extraordinary century of innovation and invention.
The Story of Electricity episode 2 – The Age of Invention
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell’s equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others.
The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field.
When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb’s law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of positive charge from an arbitrarily chosen reference point to that point without any acceleration and is typically measured in volts.