Contact forces are forces that come into play only when two objects come in contact with each other. In this wikipedia article, it is written that
Molecular and quantum physics show that the electromagnetic force is the fundamental interaction responsible for contact forces. The interaction between macroscopic objects can be roughly described as resulting from the electromagnetic interactions between protons and electrons of the atomic constituents of these objects.
If I agree with this then I’m unable to understand everyday phenomena, let’s say I push on a couch, if I use my hand to apply a force on one end of couch, the electrons of my hand will repel the the electrons on that end of the couch and will move a little inwards, this moving causes a repulsion between electrons within the couch and the electrons which have moved, this process continues till the motion of the other end of the electrons is caused. But when the last electron (of the other end) gets repelled then how would this cause the translation of my couch? If those electrons (at the other end) gets repelled a moves a little farther then they will replel the electrons in air molecules and the process gonna continue.
I want to know how does the microscopic explanation of the contact forces explain the observable translation or rotation of macroscopic objects?