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Comment by ponker | Hacker News Reader

This has always been the dumbest Eureka myth because... Isaac Newton only noticed that shit falls downwards when an apple fell on his head?! If it was something that gave him some insight into the mechanism... like two differe tobjects falling at the same time and landing at the same time, causing him to think about force and mass etc... that would make much more sense.

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As it was relayed, the apple thing was the moment that he realised that the mysterious force holding the celestial objects in their orbits was exactly the same force as gravity.

It's not that gravity was a new concept or anything. In fact, it goes back so far in our history that we still use the silly name "gravity" for the phenomenon; it was once though to be a property of an object or an element (in the "four elements" sense), and was opposed by another property called "levity". You will note that there is no current theory of levity. Galileo had already put numbers to gravity on Earth by that point, and the idea that the force holding things in their orbits acted according to an inverse square law was circulating before Newton got there. (There's no reason to believe he couldn't have come to that conclusion independently, but there's no reason to credit it to him either.)

What was missing was the connection; the generalization. That's not obvious in any way. How do you get an inverse square law to work with Galilean gravity? It smacks of equants and deferents until you find a way to put the effective mass of a body, such as the Earth, at its centre. Imagine a world in which there's some inverse square force thingy holding the moon and planets in their orbits, and there's gravity and you know how that works, and nobody has even the slightest notion that they're in any way related. And then you have the OFFS moment.

Was there really a property proposed called levity?

I thought that that was only mentioned in parodies of Newton.

e.g. https://www.sciencephoto.com/media/363707/view/caricature-of...

Yes, and it goes back at least as far as Aristotle (although he would have used a rather Greeker word). Levity would have been a property of fire and air in Aristotelian physics, where gravity was a property of earth and water.

This is only partly a myth; there are contemporary accounts from Newton's acquaintances noting how he described being inspired by observing the fall of an apple from a tree. It was the fact that an apple falls from a tree specifically in the direction of the Earth's centre that was said to have piqued his curiosity.

The apple falling on his head seems to have been a later embellishment.

A person can create their own Eureka myth. cf. eBay.

I can't see why Newton would lie to his friends and relations about something like this, but in the absence of a time machine and a brain scanner your interpretation is as valid as any other.

In any case, regardless of whether Newton's recollection of his own experiences was mistaken or confected, this is not a myth in the normal sense of being the product of invention or misconstrual by others long after the event.

Middlebrow dismissal. Revelations often come from simple events where the mind is allowed to wander. Even in our own lives we could offer a few.

https://en.wikipedia.org/wiki/Isaac_Newton#Apple_incident

The general public somehow knows two myths:

1. Galileo performed experiments related to gravity by dropping objects from a certain tower in Pisa.

2. Newton "discovered gravity" with the apocryphal Apple story.

Interesting, isn't it, that Galileo died in 1642, while Newton wasn't born until 1643? Sir Isaac would have had to have been a time traveller.

Galileo had no idea that the force that made dropping objects fall was the same force that keeps planets in their orbits, that it was one universal force. That was Newton's contribution.

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