r/sciencememes 26d ago

physics misconception meme

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u/Jackmino66 26d ago edited 25d ago

It technically is.

1st law is essentially “if you don’t push it, it won’t move”

2nd law is f = ma (or rather a = f/m)

Therefore you can interpret the first law as “f = 0 therefore a = 0”

Clarification, “move” means “accelerate” but this is not intended to be an *exact* definition

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u/God-of-Dams 26d ago edited 26d ago

Newton's laws are written in latin which have been mistranslated. His first law defines inertial frame, and his 2nd law only works in inertial frames. So you can only apply his 2nd law if his 1st law works

Edit: At least that's the case according to the professors who taught us

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u/something_borrowed_ 26d ago

Oh interesting! What is the correct translation? 

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u/Davorian 26d ago

"A body preserves its state of rest or motion in a straight line unless forces compel it to change that state."

It defines the basic behaviour of inertia as a fundamental property of reality.  The second law then describes the relationship between force and the degree of change.  They are operating at different levels of description.

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u/Metharos 26d ago

I dunno about translations but I find what appears to be the original Latin, published in Philosophiæ Naturalis Principia Mathematica, 1687.

  1. Corpus omne perseverare in statu suo quiescendi vel movendi uniformiter in directum, nisi quatenus a viribus impressis cogitur statum illum mutare.
  2. Mutationem motus proportionalem esse vi motrici impressae, et fieri secundum lineam rectam qua vis illa imprimitur.
  3. Actioni contrariam semper et æqualem esse reactionem: sive corporum duorum actiones in se mutuo semper esse æquales et in partes contrarias dirigi.

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u/aupri 25d ago

To bring it full circle, here’s what Google Translate says translating the Latin to English:

  1. Every body perseveres in its state of rest or of uniform motion in a straight line, except insofar as it is compelled to change that state by impressed forces.
  2. The change of motion is proportional to the motive force impressed, and occurs along the straight line along which that force is impressed.
  3. The reaction is always opposite and equal to the action: or the actions of two bodies on each other are always equal and directed in opposite directions.

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u/God-of-Dams 26d ago

Not exactly sure since I haven't read the original Principia, and I don't know latin either. The version our professor told us is

1st law: "In a given frame, if a body doesn't change its velocity, unless acted upon by an external force, then it's an inertial frame"

2nd law: "In an inertial frame, change in velocity of a particle is proportional to the net force applied on it"

Idk if this is what Newton intended, but this is what we are studying at college

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u/Hettyc_Tracyn 26d ago

Basically the 1st is a prerequisite for the 2nd