I’ve seen lot of theory about how it works.
But how do they get to that conclusion?
As far a i know, you can see that it’s air vibrating bc when there’s a loud noise you can feel the floor vibrating or if i drop something in a table and i place my hand on it i can feel the table vibrating as well. But how do they know it in more detail. How do they know about the pith and that it’s a wave?
how did Aristotle know it was pressure wave in the air? Did he say any reason for that
At that time it was a hypothesis. But the motion of snares was one of his inspirations.
In any case, it’s impossible to “proof” anything in physics, you can only disprove things. If enough people fail to disprove a hypothesis, for a long enough time, a hypothesis is generally accepted as true.
An early experiment that supports the hypothesis, was in the 17th century, when experiments in vacuum became possible. Robert Boyle put a mechanical bell inside a vacuum chamber and, as the bell rang, no sound was transmitted. Highly suggesting that the presence of a medium to transfer the motion is important. (1)
Changing the type or amount of gas changes the pitch, again suggesting the medium is important.