Mizukawa looked at the fountain pen on the wooden table and said: The density of the wooden table is smaller than that of the fountain pen, so does the density difference have an effect on the solid?

Liuzifeng took the lead and began to speak: We all know that density differences have no effect on solids, isn't that the case with pens and wooden tables? Yes, liquids are buoyant. This is because of the poor density. Actually, it's not quite. A piece of iron thrown into the water will surely sink. Because of the poor density. However, if you put it on a ship, it will not sink. In fact, at this time, the average density of the boat and the iron was slightly higher than that of the water. The actual reason is that water has surface tension and it is affected by the contact area. The larger the contact area, the greater the surface tension. Of course, there is a limit to surface tension. Liquids are buoyant because they are fluid, whereas solids are not. Therefore, it is not affected by the density difference. However, on the contact surface, a very small number of high-density molecules are squeezed into the low-density object.

Dueñas shook his head like a rattle: No. Solids are not fluid, and it seems that the density difference has no effect on them. Is that really the case? We know that the molecules of an object in any state are in irregular Brownian motion, but with different degrees of intensity. Although the Brownian motion of a solid is not as violent as that of a liquid, the molecules of the solid are in motion. It can be known that the molecular motion of a high-density object is not as violent as that of the molecules of a low-density object. When the molecules of the low-density object collide with the molecules of the high-density object, the molecules of the high-density object will enter the interior of the low-density object. Of course, this change requires a microscope to observe. Of course, this is talking about the contact surface.

If a large number of molecules of a high-density object enter the molecules of a low-density object, it will have a negative effect on the low-density object. And we didn't observe that it was impossible to say yin. So, the change is only at the contact surface.

Margarita said impatiently: yes, Brownian motion is indeed going on. But I don't think the high-density object molecules are getting into the low-density object. Just as there is dark matter in the universe that keeps celestial bodies from the expansion of the universe, there is a mysterious force inside low-density objects that secretly repel high-density object molecules. And this mysterious force does not weaken when it encounters liquids.

I feel that the density difference, which used to have a significant effect on solids, is offset by this force.

Mizukawa immediately retorted: If this force exists, why haven't physicists discovered it? We all know that there are four forces in the universe, strong nuclear force, weak nuclear force, electromagnetic force, gravitational force, and there is no mysterious force as you say. I agree with Duenas that molecules of high-density objects must enter low-density objects.

A pen can be placed on the table, saying that the density of the shade has little effect on the solid. However, I think the pen has a tendency to push downward. However, it was offset by the table. This means that the density of the shade can have a huge effect on the solid under certain conditions.

Of course, this is not to say that the density difference has no effect on solids at all. We know that density can affect quality. A table of the same quality cannot afford to be made of iron.

Although everyone's views are similar, there are still shining points. For us, studying a physical problem is not simple. It doesn't matter if our opinion is wrong, after all, someone needs to test whether it is feasible. Seeing each other is a kind of fate, and leaving is an inevitability. Is there a never-ending process in this world? Only those who never give up, let us continue to move forward on the road of exploration. Well, the end.