Topic 1
In his notebooks, Leonardo first stated the ‘laws’ of sliding friction in 1493. His inspiration for investigating friction came about in part from his study of perpetual motion, which he correctly concluded was not possible. His results were never published and the friction laws were not rediscovered until 1699 by Guillaume Amontons, with whose name they are now usually associated. For this contribution, Leonardo was named as the first of the 23 "Men of Tribology" by Duncan Dowson.