420 BC - Hippocrates begins the scientific study of medicine by maintaining that diseases have natural causes and puts forth the Hippocratic Oath, marking the birth of modern medicine
... by the slipping friction.
The device is covered by US patents 3,726,146 (1973) and 5,353,655 (1994) by L.A. Mishler and US patent 5,800,311 (1998) by ...