Re: Action and reaction

On 2025-07-02 15:50:32 +0000, Luigi Fortunati said:

I watch the animation https://www.geogebra.org/classic/cheqdq5u where,
at the moment of impact, the force of 22 particles pushing to the
right (action) and that of 10 particles pushing to the left (reaction)
hits the wall.

If the particles to the right and particles pushing to the left
don't interact with each other the action and reaction mentioned
above are not action and reaction of the same interaction, Even
if they do there is also mentioned interactions of each particle
with the wall and that interaction has its own action and reaction.

Mathematics tells me that the push of 22 particles is greater than the
counter push of 10 particles.

At least if the masses and velocities are the same.

Reasoning tells me that in a real experiment, after the action and the
reaction, the wall collapses to the right and not to the left,
demonstrating that the action is greater than the reaction.

Action in one interaction need not be equal to the reaction in another
interaction.

What happens to the wall depends on the properties of the wall
in addition to the number and properties of the particles. Which
particles hit first may also have some effect.

Should I blindly believe Newton's third law that tells me that the
action is always equal to the reaction or should I believe my eyes,
reasoning, mathematics and the experiment that tell me the opposite?

Newton's third law does not say that action is always the same as
reaction. It only says so about the action and the reaction in the
same interaction. Another way to say the same is that both action
and reaction is the quantity of the interaction.

--
Mikko