Imagine that you are having a catch with someone using a medicine ball. You and your friend are six feet apart, you throw the medicine ball, causing you to stagger backward, and your friend catches the ball, causing him to also stagger backward under the weight. This is an example of force acting at a distance.
Electrons play the same game of toss and catch, only instead of using a medicine ball they use a small packet of light called a photon. Weirdly, their game changes based on the distance between them. Imagine playing catch with your friend as above, only if you two get closer you start tossing a bowling ball instead of a medicine ball but you are both able to throw the bowling ball back and forth at the same speed that you threw the medicine ball. You would both stagger back quite a bit more tossing the bowling ball and be repelled more strongly. Conversely, if you take a few dozen steps back from your friend you switch out the medicine ball for a baseball. If you go further back you start throwing a tennis ball or a golf ball, at which point the repulsion between you would be quite weak.
The speed of light, the speed of the photon, is constant. When electrons play this game of catch the force of repulsion between them changes the same way the force of repulsion between people would change in a game of catch as described in the previous paragraph. If two people were electrons and they got really close to each other and started playing catch with a refrigerator, throwing it between each other at the speed of a baseball on a larger playing field, they would be rapidly repelled indeed.
Electrons are one of the fundamental building blocks of the universe and belong to a class of particles called “Leptons”. Leptos is the Greek word for “Light,” and indeed electrons are very light on an atomic scale. Picture an atom to scale: put a blueberry on the fifty yard line of a football field and scatter some dust in each of the end zones. The dust represents the electrons and the blueberry represents the nucleus, the rest is all empty space.
To go a step further, electrons define how chemistry works, how electricity affects us, and is the most ubiquitous of the Lepton family. Next time you play a game of catch you can try to feel the forces that you feel affecting you around you. Now you can remember that the forces of nature on our scale are reflected on the much smaller subatomic scale as well.