The simulation at the beginning of the resource provided an opportunity to see how electromagnetic fields work. In this section, you will look at electromagnetic forces and the history of electromagnetism.

Introduction to Electromagnetic Force

Electromagnetism is one of the two forces that dominate your everyday life (the other one being gravity). The electromagnetic force acts between all particles that have electric charge.

Force is attracted to oppositely charged particles.

Force is repulsed by particles of the same charge.

The electromagnetic force is responsible for most of the physical phenomena you see every day. It is responsible for electric forces like static electricity that causes shocks or lightning and current electricity that drives the circuitry in electronics. It is responsible for the magnetism that holds notes up on the refrigerator, allows you to navigate with a compass, and creates detailed images with an MRI. It is responsible for all electromagnetic radiation from radio signals and microwaves to visible light and even X-rays. It is responsible for atomic bonding, electron orbits, and all chemical reactions. It is even responsible for all the contact forces of physical objects. Any force of contact between two objects stems from the repulsion of electrons on the outside of the atoms in those objects.

Electromagnetic force has an infinite range but gets weaker and weaker as the distance gets bigger. Some of its effects can best be explained by field theory, and others are best explained by the carrier particle theory. The carrier of this force is the photon, most commonly observed as light.

The History of Understanding Electromagnetic Force

Watch the following series of videos about the history of understanding electromagnetic forces. During the videos, you will hear about three key scientists: Joseph Henry, Michael Faraday, and James Maxwell. Before watching the videos, list the names of these key scientists in your notes. Under the name of the scientists, take notes about their contributions to understanding electromagnetism.

Henry, Faraday, and Maxwell

There were many other contributors who have added to the understanding of electromagnetism. Click on the following link and scroll over the timeline. As you scroll over the timeline, click on the scientists to see their contribution. In your notes, choose three scientists other than Henry, Faraday, and Maxwell that you are interested in.

In the previous sections, you studied two of the four fundamental forces of nature. In the next section, you will look at the final two forces: strong nuclear force and weak nuclear force.