It’s always been presented as if he’s the first person to ever notice things fall straight down.
Maybe the first to ask why.
Of course people had seen things fall forever, but know one really came up with an real explanation of why, much less one that would explain so much about the universe.
Yeah, the point isn’t that he was the first to notice that things fall, it’s that this particular fall triggered a curiosity about “why?”, which lead to an understanding no one had presented before.
It’s supposed to illustrate Newton’s breakthrough, which is that the force that pulls the apple to the ground is the same force that governs the motion of planets.
People already knew (thanks to Kepler) that planets move around the Sun in elliptical orbits. People also knew that apples fell straight down from trees. Newton was the first to realize that the two were governed by the same forces and laws. See, if we assume that things travel in a straight line at constant speed unless acted upon by an external force - and we also assume that the Sun pulls Earth just like the Earth pulls the apple - that explains why the Earth’s trajectory is constantly bent back towards the Sun, resulting in an elliptical orbit.
Guys thanks for the replies.
The point of the story (whether or not it actually happened) isn’t that Newton noticed apples fall down; the point is that he asked himself “Why doesn’t the Earth fall up toward the apple?” At that point, anyone with Newton’s education knew the Earth was a giant ball of (mostly) rock, so it’s not a question you could easily get away from by saying “Well, the Earth is special”. And once he started thinking about that, it led to realizing that the falling apple (and minisculely rising Earth) followed the same laws as the Earth moving around the Sun. Which is a huge, huge, giant step forward in science-- even the planets follow understandable rules of physics, the same rules that apples and cricket balls follow, and humans can figure them out.
So, whether or not there’s any truth to the story, it does mark a very big step forward in human understanding.
It’s most likely true. There’s nothing unbelievable about the story and Newton told it to a number of people at the time.
The “falling apple bonked him on the head and in the shock of the moment the universal theory of gravitation came to him in a flash” story sometimes shown in cartoons is apocryphal, however.
from Boys Will Be Boys
Nope.
Aristotle had a good reason, too: Solid and wet things naturally fall down, the same way fire and air naturally rise. That’s what their nature is, so that’s what they obey, possibly after using up some “impulse” granted to them by a good throw.
This Aristotlean worldview is, apparently, the naïve intuition of most people, given how many of them think space ships stop when their engines go out, or have serious problems with the notion of inertia in general. “Impulse”, the fictional finite quality which fuels motion, is exactly what you observe on a planet with air and gravity and friction, and it takes some imagination to see that straight-line motion (or, depending on reference frame*, a complete dead stop) is natural and “falling” and “slowing down” are things you only do when there’s some external conditions forcing your to change your motion.
*(The idea of a frame of reference long predates Newton. What Newton didn’t have, and didn’t need because he was long removed from Maxwell and Lorentz and Michelson and Morley, was the notion of a speed of light independent of the velocity of the observer and, therefore, a four-dimensional spacetime where all space-time planes have hyperbolic geometry which makes velocity addition more complex than v = v1 + v2. Of course, if you take the low-speed limit of Einstein’s equations, they agree fully with the simple equations; that’s one way you know Einstein’s work is correct: All new theories must successfully explain all phenomena which the old theory successfully explained.)
The point varies slightly depending on which of the early sources you turn to.
William Stukeley’s account is:
By contrast here’s Voltaire’s [fullest version](Internet History Sourcebooks: Modern History XV) - which can’t have been heard by him from Newton directly:
So while Stukeley doesn’t mention the moon specifically, for Voltaire the point is that gravity must extend as far as it. The latter’s also the point of John Conduitt’s less detailed version, even though he probably also heard the story directly from Newton. (There are a couple of other early versions, including an earlier mention by Voltaire, but they don’t elaborate.)
The thing is there’s nothing obvious about gravity being a universal force. People could see that things up in the sky like the moon, the sun, and the stars weren’t falling to the ground. So it was natural to assume that they were not subject to whatever force made things fall here on Earth.
Yes.
This is a strong candidate for the most significant insight in all of human history.
The key connection didn’t involve the Sun at all, but the Moon: The Earth attracts both the apple and the Moon, and in both cases, the Earth’s mass is the same. The acceleration of the Moon is less, but Newton (correctly) figured that that might be because the Moon is further away, and he noticed that, comparing the apple and the Moon, there was a simple law for how the acceleration might decrease with distance, that would account for both. And then he took that simple law and, after taking a little time off to invent calculus, showed that that simple law (together with his laws of motion) would lead to all of Kepler’s laws.
Especially when friction was a part of everyday life, the concept of “a body in motion stays in motion” was a major breakthrough. Consider that in a world where wheel bearings and long smooth straightaways were pretty rare, people thought friction and rapidly slowing momentum was the natural order. IIRC Aristotle had to make up a special reason why something like an arrow could actually fly far and fast without the same obvious slowdown we see with something slid along the ground. (“the air rushing by the tail feathers helped send the arrow on its way, since they were bird feathers”)
Newton’s breakthrough was to first deduce that momentum was the rule and friction the intruder. Then the next breakthrough - that whatever gravity was, it worked equally the same on the heavens and the earth and pulled apple and moon the same. With no explanation before that, people generally assumed there was one set of rules for heavenly bodies and a different set for near the ground. (Note though he had the proof, attributed to Galileo’ experiment, that gravity was a constant acceleration no matter what the weight… also counterintuitive to the world view with friction.)
Newton’s final big breakthrough was to invent calculus and so prove that for any large sphere (he knew the earth and visible celestial bodies were relatively spherical) that ascribing a power of gravity to each piece of mass, the net attraction was the same as if there were a massive attraction from a pinpoint at the center of a sphere… i.e. gravity appeared pretty much the same despite the fact that some gravity was pulling on you from all 360 degrees of the compass, from the crust and the center of the earth.
So, from watching an apple fall, he could eventually deduce that the same force must also attract the moon. (Fun fact - his calculations for the moon’s orbit were too good. He fudged the numbers apparently to get the correct result to validate his theory.)
Where do old pianos go
long time passing
Where do old pianos go
long time ago
Where do old pianos go
Donated to charity
When will somebody play
And love the sounds they make
– AHunter3, who owns a piano acquired for free via Freecycle, and makes music on it sometimes, even if not good enough that I should quit my day job etc.
psst… I think you posted to the wrong thread.
What’s brown and if it fell out of a tree, would have killed Isaac Newton?
A piano
^^^ umm, wrong thread, sorry