Kathleen Krull talks about 'Isaac Newton,' a bio of the world's greatest scientist

Newton was a 17th-century genius who, among other things, invented calculus and discovered some of the basic principles of physics. But he was also obsessive, vindictive, and ruthless. Did you know he was such a creep before you started researching his life?

No, I didn't. But I was kind of tickled to find that out because it makes him more interesting to write about. He wasn't really a nice guy.

What do you think was wrong with him?

He had this awful childhood. That's what most historians think really had an effect on him. He grew up alone and isolated. His mother took off when he was three years old and left him with his very old grandparents, whom he didn't get along with. So from a young age, he was always alone and never formed any bonds with other people. It just seemed to haunt him for the rest of his life.

Later in the book, you mention that he might have suffered from Asperger's Syndrome.

I think that's very credible. Lately, with more knowledge of psychology and the brain, people have gone back to look at individuals like Newton and have tried to figure out what was their problem. Now some people are saying that he could have had some form of autism. He was a genius, but he just did not know how to read people or interact on any kind of social level.

Is there any truth to the story that Newton discovered the law of gravity after an apple dropped on his head?

It's hard to say. It's kind of like James Frey these days. Newton said it was true. He was the only witness, so we really don't know.

What surprised you about him?

I think the poking things into his eyeballs.

Can you elaborate?

He was an impoverished student. He would get all these ideas for different theories, and he had no money for equipment. So whenever possible, he just used himself or his own body [for experiments]. He was testing theories of vision in order to come up with theories about light. And he used his own eyeballs as experimental objects—sometimes in a benign way, like he would put a feather in front of his eyes to see what the sun looked like around the fringes of the feather. Other times he would stare at the sun for hours at a time, not realizing that he was risking permanent damage to his eyes. And then it would take him a long time to get his eyesight back.

Does it get worse?

Then he would stick things in his eyes, like a finger or other sharp objects way back underneath his eyeball to the back of the eye socket to change the shape of his eyeball to see if that would change the shape of what he was seeing. We don't really know what he was trying to prove, exactly. These were very, very early experiments, and it's amazing he didn't blind himself.

What do you think Albert Einstein was referring to when he said Newton was the greatest scientist who ever lived?

When you add up all of the things that Newton discovered and put into very careful writing, it's really amazing. He was the first person who did real experiments that conformed to what we now consider [the scientific] standard. He wrote them all down, and did them again. Other people could come in and do the same experiments and obtain the same results. What passed for science before Newton was people doing magic tricks, alchemy, and astrology—and all the other bizarre things that people were doing. He was definitely one of the first to establish the scientific method that we use today.