Legend has it that a young Isaac Newton was sitting under an apple tree when he was bonked on the head by a falling piece of fruit, a 17th-century “aha moment” that prompted him to suddenly come up with his law of gravity. In reality, things didn’t go down quite like that. Newton, the son of a farmer, was born in 1642 near Grantham, England, and entered Cambridge University in 1661. Four years later, following an outbreak of the bubonic plague, the school temporarily closed, forcing Newton to move back to his childhood home, Woolsthorpe Manor. It was during this period at Woolsthorpe (Newton returned to Cambridge in 1667) that he was in the orchard there and witnessed an apple drop from a tree. There’s no evidence to suggest the fruit actually landed on his head, but Newton’s observation caused him to ponder why apples always fall straight to the ground (rather than sideways or upward) and helped inspired him to eventually develop his law of universal gravitation. In 1687, Newton first published this principle, which states that every body in the universe is attracted to every other body with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them, in his landmark work the “Principia,” which also features his three laws of motion.
In 1726, Newton shared the apple anecdote with William Stukeley, who included it in a biography, “Memoirs of Sir Isaac Newton’s Life,” published in 1752. According to Stukeley, “After dinner, the weather being warm, we went into the garden, & drank thea under the shade of some apple trees… he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind…. occasion’d by the fall of an apple, as he sat in a contemplative mood.”
The esteemed mathematician and physicist died in 1727 and was buried at Westminster Abbey. His famous apple tree continues to grow at Woolsthorpe Manor.
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When newton was an apple fall
Newton’s home at Woolsthorpe Manor and the probable apple tree in question
In grade school you probably learned Newton’s apple story around the time you learned that George Washington chopped down a cherry tree, that people in Columbus’ time thought that the world was flat, or that the Pilgrims celebrated the first Thanksgiving in America and invited the Native Americans to join them. Since literally none of the latter three stories here are true (follow the preceding links for full details), you probably have your doubts about whether Newton actually sat under an apple tree and had something of a “eureka” moment concerning gravity.
It might surprise you to learn, then, that your teachers got one of these stories (partially) correct. Newton was indeed sitting under an apple tree when he had his so-called “eureka” moment on how gravity worked.
Although, it took him over two decades more to develop the fully-fledged theory of “universal gravitation”, first published in his Philosophiæ Naturalis Principia Mathematica on July 5, 1687. He also didn’t complete it without some ideas others had already come up with, such as Christopher Wren, Robert Hooke, and Edmond Halley (who Halley’s comet is named after); though Newton claims particularly Hooke, who corresponded heavily with Newton on gravity, and his ideas had little real bearing on his work, other than simply to inspire him to continue working on the problem.
As Newton stated when Hooke accused Newton of plagiarizing his work:
Yet am I not beholden to him for any light into that business but only for the diversion he gave me from my other studies to think on these things & for his dogmaticalness in writing as if he had found the motion in the Ellipsis, which inclined me to try it…
So perhaps “eureka” conveys much too strong of a leap. From accounts, he was more just put on the correct path while musing under the tree.
Further, it would seem that the apple didn’t fall directly on his head- at least there is no documented evidence of this. But if you discount the notion that he near instantly fleshed out his universal theory and the “fell on his head” bit, the common story is pretty accurate.
One of the best sources we have for the “apple falling on Newton’s head” anecdote is a manuscript written by Newton’s friend William Stukeley. He published Memoirs of Sir Isaac Newton’s Life in 1752, becoming one of Newton’s first biographers. Many of the incidences described in the book were recorded much earlier than 1752, including the “apple” story which was first documented in 1726, the year Newton died, and then again a year later by Voltaire in his Epic Poetry.
Stukeley’s account is as follows:
John Conduitt, Newton’s assistant and the husband of his niece, told pretty much the same story. Newton lived with the pair in his later years and doted upon their daughter. When writing about Newton, Conduitt said:
In the year he retired again from Cambridge on account of the plague to his mother in Lincolnshire & whilst he was musing in a garden it came into his thought that the same power of gravity (which made an apple fall from the tree to the ground) was not limited to a certain distance from the earth but must extend much farther than was usually thought – Why not as high as the Moon said he to himself & if so that must influence her motion & perhaps retain her in her orbit, whereupon he fell a calculating what would be the effect of that supposition but being absent from books & taking the common estimate in use among Geographers & our sea men before Norwood had measured the earth, that 60 English miles were contained in one degree of latitude his computation did not agree with his Theory & inclined him then to entertain a notion that together with the power of gravity there might be a mixture of that force which the moon would have if it was carried along in a vortex, but when the Tract of Picard of the measure of the earth came out shewing that a degree was about 69.12 English miles He began his calculation a new & found it perfectly agreeable to his Theory.
The “year [Newton] retired again from Cambridge” was 1666, which means Stukeley’s recording of the event took place some 60 years after it happened. However, both Stukeley and Conduitt, among others, appear to have independently heard the story directly from Newton himself, making it reasonable to believe a falling apple was, indeed, the source of Newton’s first significant musings over how gravity works.
There are many different places which claim to be the home of the apple tree that inspired Newton’s theory, but the most likely one—given the accounts—is located at his family home of Woolsthorpe Manor near Grantham, UK.
And, yes, there is an apple tree there today that is thought to be the apple tree in question, though it has re-rooted in the interim after being knocked over in a storm in 1890. Now around 400 years old, the tree and the property are protected by the National Trust.
If you’re curious, the tree is a Flower of Kent, which doesn’t produce very good apples for eating by today’s standards, though they are considered good cooking apples. Further, the apples in question are green, not red as is often depicted in Isaac Newton/apple images.
You’ll note, of course, that Stukeley above stated there was more than one apple tree there at the time; so whether this remaining one is “the” apple tree is a question can’t be definitively answered until someone invents a machine that can take us back in time to observe the event. That being said, Dr Richard Keesing from the Department of Physics at the University of York makes a pretty good case for why it probably is the correct tree.
Despite this uncertainty, there are a many trees that have been started as grafts from the Woolsthorpe tree, including one at Trinity College in Cambridge which sits beneath the window of the room Newton used when studying there.
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Newton’s apple: The real story
We’ve all heard the story. A young Isaac Newton is sitting beneath an apple tree contemplating the mysterious universe. Suddenly – boink! -an apple hits him on the head. “Aha!” he shouts, or perhaps, “Eureka!” In a flash he understands that the very same force that brought the apple crashing toward the ground also keeps the moon falling toward the Earth and the Earth falling toward the sun: gravity.
Or something like that. The apocryphal story is one of the most famous in the history of science and now you can see for yourself what Newton actually said. Squirreled away in the archives of London’s Royal Society was a manuscript containing the truth about the apple.
It is the manuscript for what would become a biography of Newton entitled Memoirs of Sir Isaac Newton’s Lifewritten by William Stukeley, an archaeologist and one of Newton’s first biographers, and published in 1752. Newton told the apple story to Stukeley, who relayed it as such:
“After dinner, the weather being warm, we went into the garden and drank thea, under the shade of some apple trees…he told me, he was just in the same situation, as when formerly, the notion of gravitation came into his mind. It was occasion’d by the fall of an apple, as he sat in contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself…”
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The Royal Society has made the manuscript available today for the first time in a fully interactive digital form on their website at royalsociety.org/turning-the-pages. The digital release is occurring on the same day as the publication of Seeing Further (HarperPress, £25), an illustrated history of the Royal Society edited by Bill Bryson, which marks the Royal Society’s 350th anniversary this year.
So it turns out the apple story is true – for the most part. The apple may not have hit Newton in the head, but I’ll still picture it that way. Meanwhile, three and a half centuries and an Albert Einstein later, physicists still don’t really understand gravity. We’re gonna need a bigger apple.
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Isaac Newton: Who He Was, Why Apples Are Falling
Sir Isaac Newton was born especially tiny but grew into a massive intellect and still looms large, thanks to his findings on gravity, light, motion, mathematics, and more.
Isaac Newton Kneller Painting
Far more than just discovering the laws of gravity, Sir Isaac Newton was also responsible for working out many of the principles of visible light and the laws of motion, and contributing to calculus.
Photograph of Sir Godfrey Kneller painting by Science Source
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By Kate Ravilious
Thursday, March 12, 2020
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Legend has it that Isaac Newton formulated gravitational theory in 1665 or 1666 after watching an apple fall and asking why the apple fell straight down, rather than sideways or even upward.
«He showed that the force that makes the apple fall and that holds us on the ground is the same as the force that keeps the moon and planets in their orbits,» said Martin Rees, a former president of Britain’s Royal Society, the United Kingdom’s national academy of science, which was once headed by Newton himself.
«His theory of gravity wouldn’t have got us global positioning satellites,» said Jeremy Gray, a mathematical historian at the Milton Keynes, U.K.-based Open University. «But it was enough to develop space travel.»
Isaac Newton, Underachiever?
Born two to three months prematurely on January 4, 1643, in a hamlet in Lincolnshire, England, Isaac Newton was a tiny baby who, according to his mother, could have fit inside a quart mug. A practical child, he enjoyed constructing models, including a tiny mill that actually ground flour—powered by a mouse running in a wheel.
Admitted to the University of Cambridge on 1661, Newton at first failed to shine as a student.
In 1665 the school temporarily closed because of a bubonic plague epidemic and Newton returned home to Lincolnshire for two years. It was then that the apple-falling brainstorm occurred, and he described his years on hiatus as «the prime of my age for invention.»
Despite his apparent affinity for private study, Newton returned to Cambridge in 1667 and served as a mathematics professor and in other capacities until 1696.
Isaac Newton: More than Master of Gravity
Decoding gravity was only part of Newton’s contribution to mathematics and science. His other major mathematical preoccupation was calculus, and along with German mathematician Gottfried Leibniz, Newton developed differentiation and integration—techniques that remain fundamental to mathematicians and scientists.
Meanwhile, his interest in optics led him to propose, correctly, that white light is actually the combination of light of all the colors of the rainbow. This, in turn, made plain the cause of chromatic aberration—inaccurate color reproduction—in the telescopes of the day.
To solve the problem, Newton designed a telescope that used mirrors rather than just glass lenses, which allowed the new apparatus to focus all the colors on a single point—resulting in a crisper, more accurate image. To this day, reflecting telescopes, including the Hubble Space Telescope, are mainstays of astronomy.
Following his apple insight, Newton developed the three laws of motion, which are, in his own words:
- Newton’s Law of Inertia: Every object persists in its state of rest or uniform motion in a straight line unless it is compelled to change that state by forces impressed upon it.
- Newton’s Law of Acceleration: Force is equal to the change in momentum (mV) per change in time. For a constant mass, force equals mass times acceleration [expressed in the famous equation F = ma].
- Newton’s Law of Action and Reaction: For every action, there is an equal and opposite reaction.
Newton published his findings in 1687 in a book called Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) commonly known as the Principia.
«Newton’s Principia made him famous—few people read it, and even fewer understood it, but everyone knew that it was a great work, rather like Einstein’s Theory of Relativity over two hundred years later,» writes mathematician Robert Wilson of the Open University in an article on a university website.
Isaac Newton’s «Unattractive Personality»
Despite his wealth of discoveries, Isaac Newton wasn’t well liked, particularly in old age, when he served as the head of Britain’s Royal Mint, served in Parliament, and wrote on religion, among other things.
«As a personality, Newton was unattractive—solitary and reclusive when young, vain and vindictive in his later years, when he tyrannized the Royal Society and vigorously sabotaged his rivals,» the Royal Society’s Rees said.
Sir David Wallace, director of the Isaac Newton Institute for Mathematical Sciences in Cambridge, U.K., added, «He was a complex character, who also pursued alchemy»—the search for a method to turn base metals into gold—»and, as Master of the Mint, showed no clemency towards coiners [counterfeiters] sentenced to death.»
In 1727, at 84, Sir Isaac Newton died in his sleep and was buried with pomp and ceremony in Westminster Abbey in London.
Photograph of Sir Godfrey Kneller painting by Science Source
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