One of Newton’s employees took note of the physicist’s habits in the 1680s, observing that Newton rarely went to bed before 2:00 or 3:00 in the morning, and sometimes not until 5:00 or 6:00 a.m.—and yet, “In a Morning he seem’d to be as much refresh’d with his few hours Sleep, as though he had taken a whole Night’s Rest.” During the day, Newton was never seen taking a walk or engaging in other recreation, and his assistant could recall hearing Newton laugh only once. Food was also a dispensable luxury; Newton dined sparingly and often forgot to eat at all. If reminded that he had failed to touch a meal set on the table for him, Newton would reply “Have I?” and absentmindedly take a few bites before plunging back into his work.
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