Léon Foucault

On 11 February, 1868 Leon finally succumbed to the effects of multiple sclerosis and died at the relatively young age of only 48. He hadn’t married and had no children.

His name has been inscribed on the Eiffel Tower; which is one of the biggest honours in France. Other than Foucault; only 71 other eminent personalities have been able to have their name inscribed on the Eiffel Tower.

Leon Foucault was born on September 18, 1819, in Paris, to Jean Leon Fortune Foucault and his wife. His father was well known in Parisian society for having published a series of books chronicling the rich history of France.

When his father died in the year 1829, Leon and his mother moved to Nantes due to deteriorating financial situation. The young lad was educated at home during his early years and later on he went on to study medicine.

In the year 1939, at the age of 20, he entered the medical college in Paris but quit the course midway since he could not withstand the sight of blood. After quitting he decided to study physics instead, since he was still deeply interested in the sciences.

After quitting medical school in 1939, Foucault worked as an assistant for his medical school professor Alfred Donne who was a physicist and the editor of a scientific journal.

He worked as an assistant to Alfred Donne; the editor of the scientific journal ‘Journal des Debates’, for six years till the latter’s death in 1845 and was immediately made the editor of the journal when he was just 25 years old.

He conducted plenty of experiments on his own and in the year 1850 he was successful in measuring the speed of light; which was actually only off the mark by 1%. In collaboration with his friend Hippolyte Fizeau, he developed the ‘Fizeau-Foucault apparatus’ in order to measure the speed.

In the year 1851,he performed one of his most celebrated experiments in which he showed how the Earth rotated around the sun and he used a pendulum in order to prove that. The pendulum that was used in this case came to be known as the ‘Foucault’s Pendulum’.

He started to devise a test that could test whether mirrors are spherical or not in the year 1857 and it was two years later that he came up with the ‘knife edge test’ that could show whether the mirrors in a telescope had any defects in them or not.

In recognition of his sterling efforts in the field of physics; Leon was made a member of the ‘Bureau des Longitudes’ in France in 1862 and two years later the ‘Royal Society’ in London, United Kingdom made him a member as well.

In the year 1855 he discovered the phenomenon which came to be known as ‘Eddy currents’ and the experiment showed the magnetic force required to rotate a copper disc. This knowledge found application in many practical purposes and is often called ‘Foucault’s Currents’.