Newton's First Law -- Mistranslated for 3 centuries

[jedishrfu]

TL;DR Summary

A subtle mistranslation of Isaac Newton’s first law of motion that flew under the radar for three centuries is giving new insight into what the pioneering natural philosopher was thinking when he laid the foundations of classical mechanics.

https://www.scientificamerican.com/...-first-law-discovered-after-nearly-300-years/

 

[fresh_42]

This difference might seem rather academic.

I cannot agree more. Newton's law as we know it is, given $F=m\cdot \ddot x,$
$$
F=0 \Longleftrightarrow \dot v=\ddot x =0
$$
and DiSalle wants us to believe Newton meant to say
$$
F\neq 0 \Longleftrightarrow \dot v=\ddot x \neq 0
$$
That is not worth noting. I am sure that Newton was aware of the equivalence. I wish DiSalle had quoted properly and referenced the exact location in Newton's original work - in Latin - so I could look it up.

 

[Haborix]

Well, we seem to have gotten on alright in the intervening 300 years... I have sensed no non-local changes in physics due to this discovery. But it is interesting from a history of physics point of view.

 

[vanhees71]

Philosophers...

 

[Haborix]

Philosophers...

You remind me of the group of people who are always yelling at the unemployed to get a job

 

[Andrew Mason]

The first law was Galileo's anyway. Galileo did experiments with balls rolling down and then up inclined ramps separated by flat surfaces and noticed that the ball would roll down one and up to about the same height on the distant one regardless of how far apart they were. He concluded that:
"An object, if once set in motion, moves with uniform velocity if no force acts on it."

Galileo knew about gravity and, in fact, did experiments to show that the rate of fall was independent of mass. But a ball rolling on a smooth level surface is not affected by a net force of gravity. Gravity only applied a net force if the surface was inclined.

As far as the "mis-translation" of Newton's statement of the first law is concerned, decide for yourself:

which translates in Google as:

Law 1​

Every body should persist in its state of rest or of moving uniformly in a straight direction, except in so far as it is forced to change its state by impressed forces.​

​

Projectiles continue in their motions, except in so far as they are retarded by the resistance of the air, and are driven downwards by the force of gravity. A little piece, the parts of which are continually retracting from rectilinear motions, does not cease to rotate except in so far as it is retarded by the air. But the larger bodies of the planets and comets retain their progressive and circular motions longer in spaces of less resistance.​

AM

 

[nasu]

It looks like the philosophers quoted in the OP suffer from the same missunderstanding as many intro physics students: they confuse "force" with "net force". For them a body moving uniformly in a straight line is an imaginary situation. After all, the force is always with you.

 

[PeroK]

It looks like the philosophers quoted in the OP suffer from the same missunderstanding as many intro physics students: they confuse "force" with "net force". For them a body moving uniformly in a straight line is an imaginary situation. After all, the force is always with you.

It's not just that. Inertial reference frames, flat spacetime, point masses, continuous mass densities and a whole bunch of other fundamental building blocks of physics are imaginary, idealised scenarios.

IMO, the whole point of Newton's first law was to contradict the perceived wisdom that bodies on Earth naturally slow down without any external agency; and that bodies in the heavens obey a different law (or are powered by the hand of god). It's logically irrelevant how you state this.

 

[Andrew Mason]

IMO, the whole point of Newton's first law was to contradict the perceived wisdom that bodies on Earth naturally slow down without any external agency; and that bodies in the heavens obey a different law (or are powered by the hand of god).

Feynman had an amusing take on the motion of planets:

"...what makes planets go around the sun? At at the time of Kepler, some people answered this problem by saying that there were angels behind here [pointing to the side of the planet nearest the Sun] beating their wings and pushing the planets [outward from the Sun] around an orbit. As we'll see, that answer is not very far from the truth. The only difference is that the angels sit in a different direction [pointing to the side of the planet away from the sun], and their wings go this way [inward, toward the Sun]."​

​

Feynman - The Character of Physical Law - Cornell Lectures 1965​

AM

 

[hutchphd]

IMO, the whole point of Newton's first law was to contradict the perceived wisdom that bodies on Earth naturally slow down without any external agency

The shadow of Aristotle was difficult to counter. I think that was indeed the intent. No ongoing motive force required.

 

[syfry]

which translates in Google as:

Law 1​

Every body should persist in its state of rest or of moving uniformly in a straight direction​

Wonder if he had realized at the time how really identical those are? Like did Galileo's relativity treat the concepts of 'at rest' and 'uniform motion and direction' as the same thing? Otherwise Newton might've instead have written: "Every motion should persist in its state of uniformity and direction". (whether its frame of reference is at rest or moving)

But the larger bodies of the planets and comets retain their progressive and circular motions longer in spaces of less resistance.​

That too is curious. Wonder if people in his time knew that outer space is a vacuum or nearly so?

Galileo did experiments with balls rolling down and then up inclined ramps separated by flat surfaces and noticed that the ball would roll down one and up to about the same height on the distant one regardless of how far apart they were. He concluded that:
"An object, if once set in motion, moves with uniform velocity if no force acts on it."

Had thought Newton discovered that! So did Newton merely add acceleration as the means to change the uniform velocity, or did he add in only the equation? (or both)

 

[L Drago]

Well, we seem to have gotten on alright in the intervening 300 years... I have sensed no non-local changes in physics due to this discovery. But it is interesting from a history of physics point of view.

Actually Newton's laws had a flaw. They were not able to predict the orbit of Mercury correctly which Einstein's laws predicted afterwards.

 

[L Drago]

Feynman had an amusing take on the motion of planets:

"...what makes planets go around the sun? At at the time of Kepler, some people answered this problem by saying that there were angels behind here [pointing to the side of the planet nearest the Sun] beating their wings and pushing the planets [outward from the Sun] around an orbit. As we'll see, that answer is not very far from the truth. The only difference is that the angels sit in a different direction [pointing to the side of the planet away from the sun], and their wings go this way [inward, toward the Sun]."​

​

Feynman - The Character of Physical Law - Cornell Lectures 1965​

AM

Now everyone knows it is not work of angels. I am not trying to say that this is your perspective. I am telling this was the perspective of the people at that time. It is work of Kepler's first law of planetary motion. All planets move around sun in elliptical orbits.


Hopefully in Kepler's time policies were not as strict as in Galileo as he was home arrested or something like that. The scientific community accepted Kepler's idea.

 

[jedishrfu]

Actually Newton's laws had a flaw. They were not able to predict the orbit of Mercury correctly which Einstein's laws predicted afterwards.

Every theory has flaws, and in some cases, we won't know until we find them. But this is how science works: We are always in search of a better theory to fix the flaws of the prevailing theory, and that's where the fun arises.

 

[L Drago]

Every theory has flaws, and in some cases, we won't know until we find them. But this is how science works: We are always in search of a better theory to fix the flaws of the prevailing theory, and that's where the fun arises.

Absolutely right and this is what makes Physics interesting. As Newton's theory had flaws, Einstein gave theory of general relativity which coorecty predicted the orbit of Mercury and all planets.

 

[jtbell]

View attachment 331634

which translates in Google as:

Law 1​

Every body should persist in its state of rest or of moving uniformly in a straight direction, except in so far as it is forced to change its state by impressed forces.​

​

Projectiles continue in their motions, except in so far as they are retarded by the resistance of the air, and are driven downwards by the force of gravity. A little piece, the parts of which are continually retracting from rectilinear motions, does not cease to rotate except in so far as it is retarded by the air. But the larger bodies of the planets and comets retain their progressive and circular motions longer in spaces of less resistance.​

AM

For comparison, here is the translation by Cohen and Whitman, published in 1999 by the University of California Press:

Law 1: Every body perseveres in its state of being at rest or of moving uniformly straight forward, except insofar as it is compelled to change its state by forces impressed.

Projectiles persevere in their motions, except insofar as they are retarded by the resistance of the air and are impelled downward by the force of gravity. A spinning hoop, which has parts that by their cohesion continually draw one another back from rectilinear motions, does not cease to rotate, except insofar as it is retarded by the air. And larger bodies — planets and comets — preserve for a longer time both their progressive and their circular motions, which take place in spaces having less resistance.

https://www.amazon.com/Principia-Au...al-Principles/dp/0520290887?tag=pfamazon01-20

Amazon gives the year as 2016, but I have a copy that I bought in a Borders bookstore (remember those?), with a copyright date of 1999.

 

[pines-demon]

TL;DR Summary: A subtle mistranslation of Isaac Newton’s first law of motion that flew under the radar for three centuries is giving new insight into what the pioneering natural philosopher was thinking when he laid the foundations of classical mechanics.

https://www.scientificamerican.com/...-first-law-discovered-after-nearly-300-years/

Does not matter much, Euler translated Newton's obscure passages into explicit mathematics. We should give him more credit but Euler himself was too humble and did not want any.

 

[jedishrfu]

The point wasn't really about the mistake but about Newton's insight at the time.

Much scholarship on ancient manuscripts studies how translations have lost or gained text not in the original manuscript due to changing times. This provides a nuanced view of when the original was written and why.

 

[fresh_42]

Much scholarship on ancient manuscripts studies how translations have lost or gained text not in the original manuscript due to changing times. This provides a nuanced view of when the original was written and why.

I am a bit of a fan of original papers. I remember that I once saw the first publication on Galois theory (IRL, but I cannot remember where the book is) and it was unrecognizable to me having the modern theory in mind. I have downloaded and links to
Über einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt (Einstein)
Ueber das Gesetz der Energieverteilung in Normalspectrum (Planck)
Invariante Variationsprobleme (Noether)
Philosophiae Naturalis Principia Mathematica (Newton)
Disquisitiones Arithmeticae (Gauss)
and even
Allgemeine Grundlagen einer Theorie der Gestalt von Flüssigkeiten im Zustande des Gleichgewichts (Gauss)
Classification und Integration von Gewöhnlichen Differentialgleichungen zwischen xy, die eine Gruppe von Transformationen gestatten (Lie)
and a couple more: Dedekind, Steinitz, Euclid in translation and modern, Gödel, Hilbert, Riemann, Shannon.
I downloaded most of them without the links so it's a bit troublesome to find their links again.

Hardly one of them can just be read and recognized as the revolutions they represent! What I have learned from them is primarily that they weren't the first. Noether explicitly mentions Lie's work, Einstein's Nobel Prize-winning paper has to be seen in the light of
Ueber einen Einfluss des ultravioletten Lichtes auf die electrische Entladung (Hertz, 1887)
although Einstein does not mention him (as far as my glimpse goes).

And, btw., it wasn't Newton who said

Dicebat Bernardus Carnotensis nos esse quasi nanos gigantum umeris insidentes, ut possimus plura eis et remotiora videre, non utique proprii visus acumine, aut eminentia corporis, sed quia in altum subvehimur et extollimur magnitudine gigantea

"Bernhard of Chartres said [ed.: around 1120] that we are, as it were, dwarves sitting on the shoulders of giants in order to be able to see more and more distant things than them - of course not thanks to our own sharp eyesight or physical size, but because the size of the giants lifts us up."

I could find all of those, which makes me a bit mad at DiSalle for not quoting the original paper.

 

[Mister T]

In my opinion this re-translation is not relevant to our current understanding of Newton's First Law. The law is essentially telling us that there is no way to distinguish between a state of rest and a state of uniform motion. This idea was previously articulated by Galileo extensively, then later adopted by Einstein as his First Postulate, and is now elevated in the hierarchy of physical law to the Principle of Relativity as it includes electromagnetic phenomena.