15 June 20

Happy Birthday (yesterday), Charles-Augustin de Coulomb (1736-1806)! He developed Coulomb's law of electric attraction/repulsion (showing that the force between charged objects is proportional to the inverse square of their distance). His experimental apparatus was the "torsion balance," measuring the degree to which same-charged objects repelled each other. I chose this turquoise tie (not seen publicly since July 2018) because I get a charge out of it.