The seventeenth-century English physicist appears as a tetchy hologram in Data's poker game in Descent and in person as a witness called by Q in the Voyager episode Death Wish.
Sir Isaac Newton, the English natural philosopher who set out the laws of motion and gravitation, is depicted twice in Star Trek.
In the Next Generation episode Descent he is one of three holographic scientists Data invites to a poker game, alongside Albert Einstein and Stephen Hawking. Played by John Neville, this Newton is impatient with the game, proud of his standing and irritated at having the story of the apple brought up yet again.
In the Voyager episode Death Wish, Q plucks the real Newton from his own time as a witness at the asylum hearing of the Q later called Quinn. Q argues that Quinn, by jostling the tree under which Newton sat, caused the apple to fall and so helped bring about his great insight. Peter Dennis plays Newton here, and he is returned to his era with no memory of the event.