As a child sitting under a tree, Newton saw an angel broken and bleeding in the branches above him. Curious, he touched the angel's body, and its fluid black skin engulfed him. Recognising that Newton was far too important to be erased from history, the angel told Newton that its mission was to destroy the Adversary, and Newton gave it permission to use him. He then awoke at the base of the tree with no memory of what had happened. (PROSE: Newtons Sleep)
One of his most famous accomplishments was formulating the theory of gravity. The Fourth Doctor once claimed that he sat in Newton's tree dropping apples onto his head, then explained gravity to him over dinner. (TV: The Pirate Planet) It later came to light that Newton remained upset about that event, as his nose bled for three days afterward. When the Fifth Doctor and Nyssa were arrested for forgery, Isaac Newton drew a series of interesting conclusions from a series of anachronistic coins that the Doctor accidentally passed. (AUDIO: Summer)
While working at Trinity College, "Jeova Sanctus Unus" attended the Magus' presentation at Salomon's House as a representative of the Royal Society. There, Silver revealed to him the secret of the egg, but Jeova rebuked him and denounced the egg as a tool of the Adversary; later, Nick Plainsong seduced Jeova as part of his revenge against Nate. (PROSE: Newtons Sleep)
At some point the Doctor took Newton on a trip to planet Practas Seven, but according to the Tenth Doctor, Newton didn't take the experience very well and "sat in a corner and whimpered". (COMIC: Final Sacrifice)
Jeova later became a Master of the Service; with the help of Nick Plainsong, he intended to enable Nate Silver to become the Master of Masters and use the Service to steer humankind toward becoming a Republic of Heaven ready to join the fight against the Adversary.
When Larissa and Aphra Behn encountered Jeova, Larissa recognised what was inside Jeova and attacked with the continuity needle. As Larissa struggled with the babel, time began to unravel, until Nate Silver tore the needle out of Jeova's chest. The damage to history caused by Jeova's near-erasure was undone by Faction Paradox's rituals. (PROSE: Newtons Sleep)
K9 Mark II quoted explicitly his third law of motion "Action and reaction are equal and opposite" while in E-Space. (TV: Warriors' Gate) When the Fourth Doctor quoted his "For every action, there is an equal and opposite reaction" to Romana II, she concluded that Newton invented punting. (TV: The Five Doctors, Shada)