Suppose I have a scale with a glass of water on one side and a counterweight on the other side. If I stick my finger in the glass of water I observe that the water side of the scale becomes heavier and the glass lowers.
My question is: what specifically is happening here? I'm not asking about the abstractions of buoyancy and normal forces, but what is physically going on at the molecular level that causes the glass side to dip down I'm not asking about the abstractions of buoyancy and normal forces, but what is physically going on at the molecular level that causes the glass side to dip down?
From my understanding: The water in the glass is a "sea" of water molecules attracting and repelling each other. But they're not repelling each other too far because they attract more than they repel. As I'm pushing my finger into the glass, the molecules get pushed in the direction they get hit by the finger and creates a domino-like chain reaction of molecule collisions. The chain of collisions eventually reach the boundary where the glass meets the water which results in water molecules hitting the glass more frequently and at a faster speed. I can see that this increased amount and faster collision rate would push the glass down since it's transferring all that motion energy. Once the finger is at rest in the glass, I notice the glass is still pushed down by the finger.
This is where I'm not entirely sure what the correct explanation is.
Is it the case that: Since the finger is in the glass, the water level rises. Since the water level has risen, more water is touching the glass which means there will be more collisions of water molecules with the surface of the glass which will result in more motion energy transferred from the water to the glass which results in additional movement of the glass downwards.
Or: Since the water is displaced higher up onto the glass, there is more force from gravity pulling the water molecules downwards which then sends a chain reaction of collisions downwards towards the bottom of the glass. The overall effect is that the molecules at the bottom of the glass now are hit more frequently and at faster speeds due to the downward chain of collisions caused by gravity and this results in more and faster hits on the glass.
Or is there a more specific explanation about what happens? Again, I am specifically not asking about the law based explanations (newtons third law, etc.), just the process based explanation. Again, I am specifically not asking about the law based explanations (newtons third law, etc.), just the process based explanation.