Maggie: Today we’re talking about the king, right?
John: Yes. Sir Isaac Newton.
Maggie: He’s hard to understand.
John: I agree, he is challenging. But we will give it a shot.
Maggie: What’s the topic?
John: Let’s discuss his life. And then we will tackle his significance to the history of astronomy in our next discussion. Does that work for you?
Maggie: Sure. I read that there was some controversy about his life, so this should be interesting.
The Birth and Childhood of Isaac Newton
John: The controversies started with the day of his birth. He was born on Christmas Day in 1642.
Maggie: Why’s that important?
John: Some people think that there is a spiritual significance to this day.
Maggie: Oh I get it: because he was born on Christmas Day he was somehow special.
John: Right. And here is where the controversy gets even weirder. He was born on Christmas Day by the Julian calendar, which was in use during that time. But we now use the Gregorian calendar, which was adopted in 1752. Under this calendar he was born on January 4, 1643. So the fight is really over which calendar we should use to date his birth.
Maggie: What’s funny to me is that the controversy about him actually starts with the day he was born.
John: That’s funny to me too. And the controversies multiply from there.
Maggie: I read that his father was a farmer.
John: Yes. Newton came from a family of farmers. But his father was also wealthy, owning quite a bit of land and many animals. So Newton’s life was not a hardscrabble farming life, which has been postulated. Rather, he was the son of a rich man.
Maggie: So he had it easy?
John: No, no, no. His life takes many twists and turns. In the first place, Newton’s father died three months before Newton was born. So he grew up fatherless, which is difficult in any time or age.
Maggie: I can only imagine how hard it is growing up without a parent.
John: And it only got worse for him. When he was three years old, his mother married a man named Barnabas Smith, a minister of a church in a nearby village. He was not a nice guy. He didn’t want Isaac to come and live with them, so Newton’s mother was forced to send him to live with his grandmother and grandfather.
Maggie: So he basically lost both his parents? That had to be hard.
John: I imagine it was. And the difficult cycle continues from there.
Newton’s grandfather greatly disliked him and resented having to care for him. In fact, he disliked him so much he left nothing to Isaac in his will when he passed away. And there was no love lost on Isaac’s side either. He never discussed, or even mentioned, his grandfather in conversation or in his writings when he got older.
And here is another really sad thing. Because his stepfather greatly disliked him, Isaac apparently came to resent his mother also.
Maggie: How do we know that?
John: This is really interesting and shows the psychological side of Newton. When he was nineteen he made a list of all the sins he had committed up to that year, and that list survives today. One of his sins was threatening to burn to death his stepfather and mother, and also burn the house they lived in.
Maggie: Wow, that’s harsh. But I suppose it reflects how hard his childhood was.
John: Nice insight. I agree. Things did get somewhat better when both his grandfather and stepfather died, however, the latter in 1653. Isaac’s two families were combined at that time, and he moved in with his mother, grandmother, half-brother, and two half-sisters.
Maggie: It’s sad to me that both of his stand-in father figures had to die before his life could get better.
John: It is sad to me too.
But this brings us to the next topic – his education. I saw you reading about this, so why don’t you tell me about his early education.
Educating Isaac Newton
Maggie: Okay. Shortly after he moved in with his mother he was sent to a school about five miles from his home. At this school he learned Greek and Latin, which was part of the standard curriculum at that time, and he received a good education in math.
John: Was he any good at school?
Maggie: Well, that seems to be another one of the controversies you were talking about. One article I read pointed to his school reports, which mention that he was idle and inattentive. Other articles talked about how his early education helped him grow and develop. But either way, his mother took him out of school early and tried to teach him how to run her property and estate. But apparently he didn’t succeed at that either. So who knows if he was smart, dumb, or just lazy. Any guesses?
John: He sounds like a typical teenager to me: bored with school and challenging to authority figures.
Maggie: I never thought of it that way. But that sounds about right to me.
Why don’t you explain the rest of his education, because I can’t remember the rest.
Notwithstanding his poor start, his mother eventually sent him back to school, and he finished with a flourish, becoming an excellent student. He also exhibited an extraordinary mechanical aptitude during this time, building intricate models of windmills and sundials. But it probably helped that he lived with the school’s headmaster.
Maggie: Yeah, that would make a big difference. I can’t imagine a headmaster letting him goof off during his free time. What happened to him after he finished school?
John: He was admitted to Trinity College at the University of Cambridge in 1661, which was his uncle’s college. And here is where it gets really weird. He entered as a sizar, despite the fact that his family was wealthy.
Maggie: Wait, wait. What’s a sizar?
John: It is a student who receives funding from the college in return for doing work for other students. He had to act as a valet for his fellow students.
Maggie: So it’s like a work-study program?
John: Exactly. Nice comparison.
Maggie: I don’t know, but maybe this shows the continuing rift between Isaac and his family. The fact that his mother wouldn’t pay for his school may show that they were not exactly getting along.
John: I agree with that. And I like the way you are using historical facts to draw conclusions. That is what all historians do.
What did he study at Cambridge?
John: He entered with the intent of studying law. But Aristotle dominated the college’s curriculum at that time, so he read a lot of Greek philosophy. And he supplemented this with readings from other great thinkers like Descartes, Gassendi, and Hobbes. He also read a lot of science, focusing on scientists such as Kepler, Galileo, and Boyle.
Maggie: What about math? Remember that Kepler was a math-god. Was Isaac able to understand Kepler’s math?
John: That is an interesting story. While he was studying astronomy, he realized that he didn’t understand the mathematics in the astronomy books. But rather than give up, he decided to teach himself.
Maggie: I love that he taught himself.
John: Me too.
As part of his self-education, he obtained a copy of Euclid’s Elements. He almost set the book aside after the first few pages because the proofs were way too easy for him. But then he read about parallelograms and got incredibly excited. It’s funny, but apparently he loved parallelograms. As a result, he worked his way through the entire book until he could do all of the proofs, and then added other famous mathematics books to his study, eventually becoming one of the greatest mathematicians of all time.
Maggie: Uh-oh, math nerd!
John: Yeah, and it was all because he fell in love with parallelograms. It is weird what excites different people, but the world is more interesting because of it.
And all this study proved beneficial because Newton received a B.A. degree in 1665.
Maggie: Good for him. What did he do after he got his degree?
The Plague and Home-Study Time
John: The same year that he got his degree, the University of Cambridge had to close due to the great plague.
Maggie: Just like the colleges now, closing due to the Covid-19 virus.
John: Correct. Students and faculty were sent home to prevent the spread of the plague.
Maggie: Did Isaac go home?
John: Yes. His mother let him return, and as it turns out this was a good thing. He loved working from home and he was able to make great leaps in his studies during this time period, which laid the foundations for his future writings on optics, physics, and astronomy.
Maggie: What about math?
John: Math too. In fact, Newton made some significant advances that would eventually lead to the discovery of calculus. This is so cool because the guy was not even 25 yet and he invented a whole new mathematical paradigm.
Maggie: Super-nerd! Like Bill Gates times ten.
Maggie: What happened after the plague?
The Faculty Years
John: Newton’s career took off, so to speak.
Maggie: What year are we talking about here?
John: 1667. Cambridge University had finally reopened and Newton applied for a fellowship.
Maggie: Hold on a second. What’s a fellowship? What does that mean?
John: Fellows were like professors today. They did research; they conducted tutorials and gave lectures; and they helped run the colleges. Newton was appointed to a minor fellowship at Trinity College, which got his foot in the door.
But he took full advantage of this opportunity. In fact, he worked so hard that the following year, in 1668, he obtained an M.A. degree and was appointed to a major fellowship at Trinity.
Maggie: I like stories about people who carve out their own success through hard work.
John: Me too. And it gets even better for Newton.
In 1663, Henry Lucas funded a professorship at Cambridge known as the Lucasian Chair of Mathematics. The person who holds this Chair is known as the Lucasian professor and he or she receives an annual income from the position. King Charles II formally recognized the position the next year, in 1664, and it has become one of the most prestigious academic posts in the western world.
Maggie: Wasn’t that Stephen Hawking’s position?
John: Yes! Nice point. The Lucasian Chair has been filled by the likes of Hawking and Michael Green, but the first person to hold the Chair was Isaac Barrow. He held it from 1663 until 1669. Barrow then gave up the chair because he wanted to devote himself to religious and administrative tasks, and he recommended Newton for the position.
Maggie: Why Isaac? He was still so young.
John: Because Barrow had read some of Newton’s work on mathematics, including his notes on the development of calculus, and he was so impressed that he tried to help Isaac advance his career.
Maggie: So in 1669, only two years after becoming a minor fellow, he received an M.A. degree, was granted a major fellowship, and became the Lucasian professor. That’s incredible. But you know what I really like?
Maggie: He didn’t really distinguish himself until he was in his twenties, and then things really came together for him. That should give all young people hope. There is always time to make your mark on the world.
John: I like that. It’s a great lesson from his life.
Maggie: Did he have any other achievements around this time?
John: Of course. He was elected a fellow of the Royal Society in 1672. The Society was founded in 1660 and is the oldest scientific society in the western world. It’s very prestigious.
Maggie: Any interesting controversies during this time?
John: There were a few, some of which we will talk about when we discuss his scientific theories. But here is one interesting one.
All fellows at the Cambridge University were required to become priests in the Anglican Church. The problem with this was that Newton held some pretty unorthodox religious opinions, which could have gotten him into trouble with the church if he became a priest. So he was looking for a way around this requirement when he was appointed the Lucasian professor, which helped him solve the problem. The holder of the Lucasian chair was not permitted to be actively involved in church affairs. This gave Newton the argument he needed, so he petitioned Charles II to exempt him from the priesthood. Charles II granted his petition and Newton was thereby able to avoid any conflicts with the church.
Maggie: What’s an example of one of Isaac’s controversial beliefs?
John: This is funny to me. Apparently Newton had no issues with unilaterally proclaiming that certain passages in the Bible were inauthentic. He actually wrote a religious tract later in his life disclaiming a passage from a writing of the Apostle John. You can imagine the reaction of the church if one of its priests announced that the Bible wasn’t authentic.
Maggie: Yeah, that would not have gone over well.
Tell me about some of the scientific work he did during this time period.
John: As you know, Newton laid the academic groundwork for most of his scientific work and writings during the outbreak of the plague. He then built upon this foundation during his academic years, writing some of the most famous works in the history of science. We will discuss his work in more detail in a later conversation, but here are a few key historical points.
Early in his academic career, Newton became interested in the nature of light. He started thinking about it after observing the refraction of light through a prism.
Maggie: Explain please. What does “refraction” mean?
John: Have you ever seem sunlight pass through a prism?
John: What did you notice?
Maggie: When the light came out of the prism I could see the colors of the rainbow. And the prism caused the light to bend in a different direction.
John: That is a perfect example of refraction, the bending of light through a prism. A rainbow is another example of refraction, with light bending through water droplets.
Maggie: And Newton was interested in refraction?
John: He became deeply interested in the properties of light after seeing light bend through a prism and its many colors. In fact, he became so interested he started working on a refracting telescope.
Maggie: A what?
John: A refracting telescope uses lenses to bend the light, which produces images of objects seen in the distance. By using different size lenses, a scientist can create greater magnifications. And refracting the light, instead of simply reflecting it in a mirror, creates a clearer image. Does that make sense?
Maggie: Sure. Different size lenses in the telescope make the planets and stars look bigger or smaller, and a refracting telescope produces clearer images.
John: Nice! Newton invented the refracting telescope in 1668. He gave a demonstration of it to the Royal Society in 1671, which is one of the reasons he was admitted as a member in 1672.
Newton also lectured on the topic of light in the early 1670s, and his notes from these lectures were later expanded into his famous work on the subject: Opticks. This work was eventually published in 1704.
Maggie: Tell me about his greatest book, the Principia. When did that get published?
John: The full title to the book is Philosophiae Naturalis Principia Mathematica. It is called the Principia for short, and it was published in 1687.
The Principia is generally regarded as the greatest book on science ever written, which probably remains true even today.
Maggie: This is where Newton talks about his laws of physics, right?
John: Yes. This is the book in which Newton developed his three laws of motion, which we all learn in high school. The three laws describe the relationship between any given object, the forces acting upon that object, and the motion resulting from the acting forces. The laws can be simply stated:
- Every object will remain at rest or in a state of uniform motion unless an external force acts on it.
- Force equals mass times acceleration: f = m*a.
- For every action in nature, there is an equal and opposite reaction.
Maggie: And these laws formed the foundation of modern physics, right?
John: Again, I see that you have been doing some reading.
Maggie: But I have a question: can you explain to me how Newton’s physics relates to our discussion of astronomy? I am waiting for that connection.
John: I sure can. There is a fourth law in the Principia that we need to mention: the law of universal gravitation:
- Every object in the universe attracts every other object in the universe with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between the two objects.
This law helped scientists explain the orbits and positions of the planets, moons, and comets with an accuracy never accomplished before. In fact, Newton’s fourth law and its corresponding mathematical formula are still used today by scientists and NASA to establish the orbits of satellites.
Maggie: Like you said, it is the greatest scientific book written. Ever!
John: But do you want to hear something even more interesting?
John: Newton also had some less-than-scientific interests. He was deeply interested in alchemy.
Maggie: Do you mean like turning other metals into gold? Like magic?
John: Exactly. Apparently he was obsessed with alchemy and spent a good part of his time experimenting with various metals.
Maggie: Really? I don’t get it. How can a scientist be so taken in by alchemy?
John: Well, who really knows. But we should remember that, at this time, scientists were just beginning to understand the chemical make-up of metals. It was a new field and they thought if they could manipulate the make-up, they could create gold and become rich. So we can’t fault Newton too much, since he didn’t have the benefit of our hindsight.
Maggie: Okay, I get it. But it’s still weird.
John: I agree. But let’s turn to his later life now.
Newton’s Retirement from the Academic Life
Maggie: Okay. Didn’t Newton have a nervous breakdown later in life?
John: Yes he did. In 1693 he retired from research after suffering the second of his breakdowns.
Maggie: What caused them?
John: There are several speculations, as you can imagine, including frustration with his research and lack of close personal friendships.
Maggie: Do you have any interesting thoughts about it?
John: Yes, two. He may have been suffering from chemical poisoning due to his alchemy work. Mercury poisoning, especially, could have been part of the cause. But it is also possible that he suffered from depression his entire life.
Maggie: I am not surprised, especially given what he went through when he was young.
John: Agreed. And that depression may have aided in his breakdown. But whatever the reason, this last breakdown caused him to leave the university.
Maggie: What did he do then?
John: Well, he didn’t formally retire from Cambridge until 1701. But in 1696 he took a job at the Royal Mint as Warden, and three years later he was promoted to Master. He held this position for the next thirty years. This position was supposed to be an easy job, given to him as a reward for his scientific work. But this wasn’t the case for Newton. He worked really hard at the job, accomplishing an entire recoinage process and prosecuting many counterfeiters during his time as Master. He also made a lot of money, becoming very rich.
Maggie: Did he still work in science?
John: To some degree, yes. Most importantly, he was elected president of the Royal Society in 1703, and he was re-elected to this post every year until he died. As president, he had a lot of influence over the scientific world at that time.
Maggie: And wasn’t he knighted?
John: In 1705. He was only the second scientist to be knighted, after Sir Francis Bacon.
Maggie: When did he die?
John: He died in his sleep on March 20, 1727. His body was buried in Westminster Abbey, but here is something interesting. After his death, Newton’s hair was examined. It contained mercury, likely as a result of his alchemy experiments.
Maggie: Just like you said—this could have caused his mental illness.
Maggie: Do you want to know what I think is the saddest thing about Isaac?
Maggie: He died alone, without ever having a great love.
John: That is true. He resisted getting involved with women and was alone his whole life. He even once accused the philosopher John Locke of trying to “embroil me with women.”
Maggie: I get the whole “science is my love” idea, but it sure seems lonely to me.
John: Me too.
After he died, Alexander Pope wrote a great couplet about him. Want to hear it?
John: It went like this:
Nature and nature’s laws lay hid in night;
God said “Let Newton be” and all was light.
Maggie: That is so cool. And it shows his greatness to western science.
Now that we have discussed Newton’s life, are we going to turn to his contributions to astronomy?
John: Yes, in our next discussion.
Maggie: Great. See you then.