Objects in Contact

## Question:

My son takes Physics in high school. He said when we touch any object that there is an electromagnetic field between you and the object. He says that we don't actually touch the object. Is this correct? Why? Please respond

thanks,

## Answer:

Your son is correct. Objects are made up of atoms that have a positive electric charge concentrated at the center and an equal amount of negative charge distributed around the outside. The overall size of the atom is so small that the separation between these charges is practically zero when seen from any large distance, like a thousandth of an inch for example. Therefore objects at those distances experience no force from one another. When two objects get really close however, each sees the other as predominantly negatively charged since the negatively charged shells are about as close to each other as each shell is to the positive charge in its atom core.

Since opposite charges repel each other, a force develops that resists any closer approach of the two atoms. This force is transmitted from atom to atom in each object causing slight movement of the atoms closer to the point of "contact" between the objects, allowing more and more atoms to get close until the total resisting force between atoms equals the force tending to bring the objects together.

This simple picture neglects a whole bunch of quantum mechanical complications but is essentially correct.