Isaac Newton today is venerated as one of the greatest scientists who ever lived -- the father of classical mechanics and co-creator of calculus. But in his day, Newton was known for many things, including some very bizarre behavior and a personality that might be considered quirky at best.

Consider these 10 fascinating facts about Newton:

Fact #1: Newton was a big-time sinner. At least he thought he was. At the tender age of 19, the future mathematician committed to paper a list of 48 sins of which he was guilty. Transgressions ranged from "peevishness" at his mother to "having uncleane thoughts words and actions and dreamese." He also confessed to "eating an apple at Thy house," though he gave no word as to whether it was THE apple (see #9 below).

Fact #2: He stuck a needle in his eye socket -- on purpose. In Newton's time little was known about the properties of light. In fact, people weren't even sure whether the eye created light or collected it, James Gleick, author of a 2003 biography of Newton, told HuffPost Science in a telephone interview. Curious, Newton embarked on his own detailed study of optics -- and he wasn't above acting as his own guinea pig, probing his eye with a blunt needle known as a bodkin. As he wrote in his journal:

I tooke a bodkine gh & put it betwixt my eye & [the] bone as neare to [the] backside of my eye as I could: & pressing my eye [with the] end of it (so as to make [the] curvature a, bcdef in my eye) there appeared severall white darke & coloured circles...



Notebook belonging to Isaac Newton describing an experiment he conducted on his himself in which he placed a sharp instrument between his eye and the bone in order to induce the sensation of color.

Fact #3: He had two nervous breakdowns. In 1678, after engaging in a dispute over aspects of his theory of optics, Newton is believed to have suffered a nervous breakdown. In 1693, he had another, after which he retired from scientific research. Newton blamed his second breakdown on lack of sleep, though historians mention other possible causes, including chemical poisoning from experiments (see #8 below) as well as the accumulated effects of chronic psychological depression.



Newton's own first edition copy of his Philosophiae Naturalis Principia Mathematica.

Fact #4: He was born a preemie to poorly educated parents. Newton was born in the English county of Lincolnshire, the only son of a farmer, also named Isaac Newton, and his wife, Hannah Ayscough. Born three months premature, he was so small at birth that he could have fit inside a quart mug, his mother reportedly said. His father was illiterate, and his mother was barely able to read, Gleick told HuffPost Science. "He was able to go to university because his mother remarried and so there was some money," Gleick said.



Interior of the Wren Library at Trinity College, Cambridge.

Fact #5: He waited tables. As a student at the University of Cambridge, Newton had to wait tables. He was a "sizar," Gleick said, referring the term used to describe an undergraduate who received financial assistance in return for performing menial duties. In Newton's case, that included being a waiter and taking care of other students' rooms.

Fact #6: He was a lonely guy. Some have speculated that Newton suffered from a mental illness (perhaps bipolar disorder) or autism. That's hard to know for sure, but one thing that is clear is that Newton was chronically lonely. "We can see this when he was a child and when he was an old man," Gleick said. "He got into fights."

Fact #7: He escaped the Great Plague. When a devastating outbreak of bubonic plague hit Cambridge in 1665, Newton and his classmates were sent home to ride out the epidemic. But the budding mathematician made good use of his time -- by inventing calculus.

Fact #8: He practiced alchemy. Though rightly celebrated for his scientific genius, Newton also dabbled in alchemy -- a pseudoscience whose aim is to turn lead and other base metals into gold.

Fact #9: He didn't think up his theories after seeing an apple fall to the ground. "Most people think that Newton was hit on the head with an apple," Gleick told HuffPost Science. "But it's probably not true." What likely was true, he said, is that Newton realized that the same invisible force that caused apples to fall to the ground also affected the movements of the moon.

Fact #10: He died a virgin. Newton never married and, though it's impossible to verify, is widely believed never to have had sex.