# FeaturedB Why were Newton's laws of motion discovered so late?

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1. Jan 2, 2018

### thebosonbreaker

Hi,
I had a thought recently which gave rise to a rather interesting query. A helicopter works and is able to fly due to Newton's third law of motion. The propellers rotate at a high speed and exert a force on the air beneath them. By N3L, the air therefore exerts an upwards force on the propellers, thus causing the helicopter to lift off the ground and begin to fly.
An understanding of Newton's laws is integral to the design and operation of the modern-day helicopter. The first modern-day helicopters came about in the 1940s so the laws were well known by then...but here's the thing.
Newton published his laws in the Principia in 1687, but Leonardo Da Vinci had already invented the 'Aerial Screw' which was one of the earlier helicopter-like machines. But according to the internet, Da Vinci first published his detailed plans of the aerial screw in 1485, a staggering 202 years before Newton published his laws and of course well before Newton himself was born.
Clearly Da Vinci had to have an understanding of at least something akin to the basic laws governing motion, so why did they only become a breakthrough in 1687 and not many years before? With Da Vinci possessing perhaps one of the greatest minds in history, one would believe that he would have explored this in greater detail. You can't build (what was considered in that era...) such advanced and pioneering inventions as that of the aerial screw without understanding these underlying principles.
Does anybody have any thoughts on this, or am I missing out any crucial details? I'd be interested to hear!

2. Jan 2, 2018

### A.T.

So do rockets, and sails and tons of other stuff, that was build and used, not just drawn, long before Da Vinci.

Many people had empirically acquired qualitative intuition of them for specific cases. The big leap is to generalize them to everything and to make them quantitative.

3. Jan 2, 2018

### Staff: Mentor

You imply one crucial detail you may be missing: da Vinci didn't build his aerial screw.

Da Vinci's drawings are akin to (but in general superior to, which is impressive enough) the "artist's impressions" you see in the media for such things that haven't actually been invented yet. It is unlikely his aerial screw would have worked.

The Wright Bros demonstrated how important it was to take a scientific approach to the problem of flight(experimental anyway) and succeeded because of it, whereas most of their competitors were just taking shots in the dark.

4. Jan 2, 2018

### Khashishi

Had Da Vinci known about Newton's laws, he would have put two counterrotating screws on the airship. A single screw would never work.

5. Jan 2, 2018

### sophiecentaur

The answer to the title question is FRICTION.
Things slow down naturally. The heavenly bodies had to be driven round their paths by some agency. Why would anyone think differently until there was some serious effort at proper experiments and friction could be identified as a force and not a natural tendency. Newton just happened to be smart and around at the right time for a paradigm change.

6. Jan 2, 2018

### r8chard

In my opinion, I think a big reason was Newton was the right thinker at the right time of intellectual ferment sweeping Europe. He had the luxury of education and placement, that permitted him the tools and time to make discoveries. Inn addition, among his peers was a strong bond of wonder and communication is a society that encouraged them to compete for status and glory. And his achievements were famous among his peers across Britain, Scotland and Europe.
However, iy was Émilie du Châtelet whose own brilliance translated Newton’s work from mediocre Latin into French. Which language was cosmopolitan. Used by the rising Bourgeoisie, government bureaucrats as well as the Aristocrats, for diplomacy and philosophical disputes. This was a rime when philosophy included all the sciences. This Lady of Genius would popularized and rendered Newton’s Genius understandable to many more people.
/wiki/Philosophiæ_Naturalis_Principia_Mathematica#Annotated_and_other_editions
“..... Émilie du Châtelet also made a translation of Newton's Principia into French. Unlike LeSeur and Jacquier's edition, hers was a complete translation of Newton's three books and their prefaces. She also included a Commentary section where she fused the three books into a much clearer and easier to understand summary. She included an analytical section where she applied the new mathematics of calculus to Newton's most controversial theories. Previously, geometry was the standard mathematics used to analyse theories. Du Châtelet's translation is the only complete one to have been done in French and hers remains the standard French translation to this day.[103] .....”

7. Jan 2, 2018

### Stephen Tashi

That's not a good description of how helicopter blades generate lift.

8. Jan 4, 2018

### r8chard

I am listening to KUSC radio and they announced that Isaac Newton was born this day, January 4, 1643.

So, here is a big shout out "HAPPY BIRTHDAY, SIR ISAAC!!!"

9. Jan 4, 2018

Staff Emeritus
Actually, he was born on December 25, 1642.

10. Jan 4, 2018

### jbriggs444

Wikipedia explains:

"During Newton's lifetime, two calendars were in use in Europe: the Julian ("Old Style") calendar in protestant and Orthodox regions, including Britain; and the Gregorian ("New Style") calendar in Roman Catholic Europe. At Newton's birth, Gregorian dates were ten days ahead of Julian dates: thus his birth is recorded as taking place on 25 December 1642 Old Style, but can be converted to a New Style (modern) date of 4 January 1643."

[The physics of his birth are invariant, but the coordinates assigned to the event are not]

Last edited: Jan 4, 2018
11. Jan 4, 2018

### r8chard

ibriggs444, Newton was such a genius, he managed to be born on both dates. In order to collect double the presents!

I believe his mother grumbled some choice, pithy Anglo-Saxon terminology at having to endure such an obstreperous brat.

12. Jan 5, 2018

### sophiecentaur

He was 'not a nice person', by all reports but was around at a time of change in knowledge and thinking. He bullied Hooke, who I expect he recognised as equally smart. If Newton had become ill and died, someone like Hooke would probably have carried the baton and we could have had Hooke's 1,2 and 3 Laws of motion.
I feel the same about Einstein. He was first over the line but there were a number of others who could have got there after a bit of a delay. It has to be true that, without Einstein's existence, we would not be using Newtonian Science today - on PF .
This is not to belittle any of their achievements but the modern personality cult needs to be treated with reservations.

13. Jan 5, 2018

### r8chard

sophiecentaur, I concede that you have some good points there. My view is that Newton and Einstein were at the hub of a multitude of contributors. Their genius was to to collect, correlate and clarify the scientific research of their time.

Unfortunately, the Public is uninterested in complicated. They want short pithy baitclick headlines with A hero and A villain.

However, if you check the textbooks commonly used for the sciences, there is no shortage of credit given to the contemporaries of Newton and Einstein. The forums on this site are lavish in using the names of other scientists as shorthand for mathematical formulas and physics theories and astronomy.

14. Jan 5, 2018

### sophiecentaur

I don't know too much of the history of Newton's appreciation by his scientific peers but I think it's well known that he was not a very nice person and was interested in his personal status. Strange that someone with such an analytical mind should turn to Magic and illogic in his later years. But history has chosen his name as an icon for the progress made during his era. Likewise for Einstein - but, apart from the natural bickering, I think he was less 'unpleasant' with his peers (just with his wife, I read). Again, his name is shorthand (with the public) for all that went on a hundred or so years ago.

15. Jan 5, 2018

### Prophet

Some speculate that he was autistic.

16. Jan 5, 2018

### sophiecentaur

That figures. For some reason, he suddenly took up Alchemy. That was nutty.

17. Jan 5, 2018

### Prophet

He also developed a great interest in religion. He calculated that Jesus Christ would return in 2060.

18. Jan 5, 2018

### sophiecentaur

I doubt that I will be able to check that out but some PF members should be in with a chance.

19. Jan 5, 2018

### FactChecker

This is worth emphasizing. Newton's ideas were, in many ways, very counter intuitive. Before Newton, anyone would swear that there were different rules for objects in space, like the moon, which floated in the sky, versus objects on the ground which fall to Earth. So they would think that there were no universal laws. Newton could see through to the truth, establish it in enough rigor to convince himself and others, explain other consequences like the gravitational pull of the Moon creating tides, and get the math so well understood that accurate calculations and predictions could be made. That was true genius. And that is why no one did it earlier.

Last edited: Jan 7, 2018
20. Jan 6, 2018

### Mister T

Newton's Three Laws in and of themselves pale in comparison to the conclusions drawn from them.

The laws formed the basis of a framework of knowledge that continues to this day to be used to draw important conclusions. About 25 years ago I attended a series of lectures given by an atomic physicist making preparations to build an "atom trap". He told us and showed us how to do most of the math using only newtonian physics, there wasn't an $h$ or a $c$ anywhere in a lot of these calculations.