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In 1822 the British scientist Michael Faraday, working at the Royal Institution in London, created the first electric motor, where an electric current was used to produce motion. The story goes that he made his discovery over the Christmas period, possibly on Christmas day. His version involved a wire dangling in a glass vessel filled with mercury, and he is supposed to have said 'there they go' when the motor started working.
Many years later, one of us (George Auckland) wanted to recreate this experiment for a television programme. Bill Coates, who was a 'science communicator, lecturer and technician' who worked at the Royal Institution, was given a mince pie by his wife on Christmas day in 1986, and he realised that an aluminium mince pie case together with a strong saline solution could replace the use of mercury in the original experiment.
Tim demonstrates this modern version, and in the middle of the pie case he is using a neodymium magnet, which of course is stronger than the original magnet that Michael Faraday would have used.
The battery is connected to both the pie case, which is sitting on a piece of aluminium foil, and the other terminal is connected to the wire that is holding the moving piece of wire that hangs down into the salt solution. The salt solution conducts electricity, which completes the circuit, and the wire revolves around the magnet. Reverse the direction of the current and the wire revolves in the other direction. Turning the magnet the other way up also reverse the direction that the wire revolves.
This motor didn't generate any useful power, but it demonstrated a principle, and it was not long before more useful motors were developed.
Fleming's left-hand rule, which Tim refers to, can be used to work out which direction the wire will move in.
Michael Faraday's subsequent discoveries included the induction coil or transformer, and also the generator. He effectively laid the foundations for the modern discipline of electrical engineering.
