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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Sir isaac newton apple on head
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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Правда ли, что яблоко упало на голову Исаака Ньютона?
Вы наверняка слышали историю про яблоко Ньютона. Она гласит, что молодой Исаак Ньютон сидел под яблоней, когда его ударило по голове падающим фруктом, и «О, эврика!» , этот момент побудил его внезапно придумать свой закон всемирного тяготения. Давайте разберемся, правда ли это.
Исаак Ньютон был сыном фермера и родился в 1642 году в Англии. В 1661 году будущий ученый поступил в Кембриджский университет.
Четыре года спустя из-за вспышки бубонной чумы, обучение было приостановлено (дистанционного обучения еще не было, к сожалению), и Ньютон вернулся в дом своего детства Вулсторп.
Однажды, находясь в поместье отца, Ньютон прогуливался по саду и увидел падение яблока с дерева. Нет никаких доказательств того, что плод действительно приземлился ему на голову, но наблюдение Ньютона заставило его задуматься, почему яблоки всегда падают прямо на землю (а не на бок или вверх), и помогло ему в конечном итоге разработать закон всемирного тяготения.
В 1687 году Ньютон впервые опубликовал этот принцип, согласно которому каждое тело во Вселенной притягивается ко всем другим телам с силой, которая прямо пропорциональна произведению их масс и обратно пропорциональна квадрату расстояния между ними.
В 1726 году Ньютон поделился анекдотом о яблоке со своим другом Уильямом Стьюкли, который позже включил эту историю в биографию » Воспоминания о жизни сэра Исаака Ньютона «, опубликованную в 1752 году. Стьюкли писал, что Ньютон размышлял о понятии гравитации и раньше, но именно падение яблока на голову помогло ему найти ответы на интересующие его вопросы.
Судя по дневникам самого Ньютона, он, действительно, несколько лет размышлял над вопросами тяготения, но падение плода на свою голову в своих записях не упоминал.
На звание «той самой яблони» претендуют теперь несколько деревьев. В Королевской школе в Грэнтэме, в которой получил начальное образование Ньютон, утверждают, что дерево было куплено школой, выкорчевано и перевезено в школьный сад. Сотрудники поместья Вулсторп(ныне музей) оспаривают это и утверждают, что дерево, растущее в их садах, то самое, которое описал Ньютон.
Однозначно, потомка первоначальной яблони можно увидеть за главными воротами в Кембридже, под окнами комнаты, в которой жил Ньютон, когда учился там.
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7 of Isaac Newton’s Most Important Ideas
Isaac Newton was one of the greatest thinkers in human history who practically invented modern physics.
When you think about Isaac Newton, you probably think of the apocryphal story about an apple falling on his head, giving him the idea for the theory of gravity. Y ou might also think about the fact that he is one of the most influential physicists and scientists of all time.
Born in 1642, Sir Isaac Newton was raised by his grandmother until the age of 12. His mother pulled him out of school at age 12 to have him tend the farm. Newton found farming monotonous, and he was soon sent back to school.
He studied law at Trinity College Cambridge, taking care of wealthier students’ rooms to pay his bills. During his time at Cambridge, Newton kept a set of notes, entitled «Quaestiones Quaedam Philosophicae» («Certain Philosophical Questions«). The notes reveal that Newton had already discovered the key ideas behind a new approach to mathematics: calculus. He graduated without honors or distinctions but did earn the title of scholar and four years of financial support for future education.
In 1699, Newton received his Master of Arts degree. He also came across Nicholas Mercator’s published book on methods for dealing with infinite series, which sparked a renewed interest in mathematics. He published a treatise, De Analysi , expounding his own ideas. This came to the attention of the mathematics community, and Newton was eventually given the Lucasian professorship at Cambridge.
Over the course of his life, Newton was responsible for a number of important ideas and theories. Let’s take a look at just 7.
Newton’s Laws
In 1687, Isaac Newton developed his three laws of motion after discovering and studying gravity. They are:
- Every object stays in its state of rest or uniform motion unless disturbed by an external force. (Law of Inertia)
- Force equals mass times acceleration.
- For every action, there is an equal and opposite reaction.
Orbital Cannon
Isaac Newton liked to play with ideas around the concept of universal gravitation. In thought experiments about it, he described a mountain that would be so tall it poked into space. He considered that if such a mountain existed, you could place a cannon on its peak to launch objects into orbit.
This was a way to explain how one object might orbit another.
He theorized that if you gave the cannonball the perfect amount of gunpowder on the launch, you could give it enough velocity to fall towards earth at the same rate the planet curved away from it. The cannonball would continue in free fall all the way around the planet, in effect, orbiting it.
The Philosopher’s Stone
Isaac Newton was not only interested in mathematics and physics, but he also worked in areas that strayed away from what we now consider more traditional science, and into the realm of alchemy and mysticism, including ways to concoct the magical philosopher’s stone.
The «philosopher’s stone» was a mythical substance that alchemists believed had magical properties, including being capable of bestowing the abilities of transmutation and immortality. In theory, the stone could turn lead into gold, or cure any disease.
It is important to remember that when Newton was alive, alchemy was still seen by some as legitimate science.
Documents that have recently come to light give Newton’s handwritten instructions for making «philosophic» mercury. The document title translates, in part, to «Preparation of the [Sophick] Mercury for the [Philosophers’] Stone.»
Calculus
Isaac Newton and Gottfried Wilhelm Leibniz are said to have independently invented calculus at around the same time, although each claimed the other had stolen his work. Newton discovered that algebra and geometry weren’t powerful enough for the science he was working on, so he developed a new means of mathematics in order to decode the world around him properly.
At its most basic, calculus is all about studying the rate of change of a quantity over time. In his work on gravity, Newton first tried to describe the speed of a falling object. When he did this, he found that the speed of a falling object increases every second, but that there was no existing mathematical explanation for this. The issue of movement and the rate of change had not yet been explored to any significant degree in the field of mathematics.
Newton also incorporated planetary ellipses into his theory of gravity, to try to explain the orbit of the planets. By using calculus, he could explain how planets moved and why the orbits of planets are in an ellipse.
One of his major breakthroughs was finding that the gravitational force that holds us to the ground is the same force that causes the planets to orbit the Sun and the Moon to orbit Earth.
Refraction of Light
In 1704, Newton wrote a book on the refraction of light titled Opticks. It changed the way that scientists thought about light and color.
Scientists in the early 18th century knew that rainbows formed when the light was refracted through water, but they had no perception as to why this produced so many colors. The common theory was that the water «dyed» the rays of the sun or that color was created by the mixing of light and dark.
Beginning in 1666, Newton conducted studies with a lamp and a prism. Newton developed a setup that allowed him to refract the rainbow rays back into white light, which demonstrated that the white light is actually made up of a mixture of distinct colored rays, which are distinguishable when refracted in a prism. His experiments also revealed that color arose primarily from selective absorption of light by materials.
Cool ing
Newton became particularly interested in the physics of how things cool. During his studies, he particularly focused on red-hot iron balls in different fluids. He noticed that the difference in temperature between the iron ball and the air surrounding it ended up being less than 50 degrees Fahrenheit, or roughly a difference of about 28 degrees Celcius.
He established a correlation between the rate of heat loss and the temperature difference of the ball and fluid.
Newton’s Law of Cooling states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings. This law has become a guiding principle in the field of thermodynamics.
Gravity
While the legend is that Isaac Newton discovered the principles of gravity when he was hit by a falling apple, that story probably only has a grain of truth.
Whatever really happened, Newton realized that some force must be acting on falling objects, like apples, because otherwise, they would not start moving in the first place (see Newton’s First Law of Motion).
Newton publicized his Theory of Universal Gravitation in the 1680s. It set forth the idea that gravity was a predictable force that acts on all matter in the universe, and is a function of both mass and distance. The theory states that each particle of matter attracts every other particle with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
As Newton also began observing planets, he realized that the moon should just move in a straight line away from Earth unless there was a force keeping it close to our planet. This force was gravity.
The work of Newton actually helped prove that the Earth was not at the center of the solar system, rather that it moved along with other planets and orbited around the sun.
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