# Who was the first scientist who calculated with physical quantities? [closed]

Newton changed the way we look at physics by giving a simple rules such like:

F=ma

In these equation we don't count with specific numbers, we are only stating what are the dependences.

Who was the truly first scientist who counted only with dependences of one factor on another?

• Four comments: (1) Newton did not give is $F=ma$. Newton was rather verbose and geometric in his writing. (2) Based on what you appear to be asking, instead of "physical quantities", I suggest you use "symbolically". (3) Are you asking about symbolic algebra, or the use of symbolic algebra in the sciences? (4) As is, the question is rather unclear. – David Hammen Mar 5 '16 at 19:49

Newton's formulation of his II Law of Motion into the Principia is not "symbolic"; see:

The first "algebraic" formulation of Newton's law of motion is due to:

XXII. [...] after having decomposed all the forces acting on the body into the three perpendicular components $$P, Q, R$$ [...] the movement of the body will be described by the three following formulae:

$$I. \ \ 2M ddx=P dt^2 \ \ \ II. \ \ 2M ddy=Q dt^2 \ \ \ III. \ \ 2M ddz=R dt^2.$$

An early example of dependency between physical magnitudes is Aristotle (wrong) law of motion:

If, then, $$A$$ is the mover, $$B$$ the moved, $$C$$ the distance moved, and $$D$$ the time, then in the same time the same force $$A$$ will move $$\dfrac 1 2 B$$ twice the distance $$C$$, and in $$\dfrac 1 2 D$$ it will move $$\dfrac 1 2 B$$ the whole distance $$C$$; for thus the rules of proportion will be observed [Physics, Book VII, 249b27-250a9].

• It doesn't matter to me how did he came to this equation. My question is, who was the first man, who used letters in the equations. I know Newton didn't put on the table an axiom F=ma and I'm not claiming he was the first to use letters (or anything else). Sorry, I really don't understand your answer. – Probably Mar 4 '16 at 18:24
• What about Archimedes' law? – Probably Mar 5 '16 at 20:20
• @Probably - this law ? – Mauro ALLEGRANZA Mar 5 '16 at 20:23
• I'd prefer the general formulation: "Any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object." – Probably Mar 5 '16 at 20:27
• "Unfortuantely", the above was the formulation used by Archimedes... – Mauro ALLEGRANZA Mar 5 '16 at 20:32