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American physicist and author George Johnson has come up with a list of the 10 most beautiful experiments in science. From Galileo rolling marbles down a plank to Pavlov and his salivating dogs, he manages to capture something of the heart stopping wonder of discovery.

Our science correspondent Tom Feilden asked Bristol physicist Dr Len Fisher to recreate one of the top 10 - Robert Millikan’s experiment to measure the charge of a single electron.

The experiment uses only a perfume atomiser, 2 metal plates (pictured) a battery and a microscope.

The perfume atomiser squirts an oil mist between the metal plates which are connected to a 1000 volt battery. As the oil particles fall the power is turned on and the path of the droplets disrupted.

Looking into the microscope you can see the droplets of oil rise and fall as the power is cranked up. The speed at which they move tells you how many electrons are clinging to each droplet.

This is the view looking down the microscope. The white dots are the electron charged oil particles, which rise and fall like dust in sunlight as the charge is applied.

Oil drop experiment Wikipaedia
10 Most Beautiful Experiments George Johnson
Opening the Door to Science - Len Fisher

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