Course Information: 8.02

Electromagnetism I is an introduction to electromagnetic fields and forces. Electromagnetic forces quite literally dominate our everyday experience. The material object presenting this text does not fall through the floor to the center of the earth because it is floating on (and held together by) electrostatic force fields. However, we are unaware of this in a visceral way, in large part because electromagnetic forces are so enormously strong, 10⁴⁰ times stronger than gravity.

Because of the strength of electromagnetic forces, any small imbalance in net electric charge gives rise to enormous forces that act to try to erase that imbalance.Thus in our everyday experience, matter is by and large electrically neutral, and our direct experience with electromagnetic phenomena is disguised by many subtleties associated with that neutrality. This is very unlike our direct experience with gravitational forces, which is straightforward and unambiguous.

The objectives of this course are to tease out the laws of electromagnetism from our everyday experience by specific examples of how electromagnetic phenomena manifest themselves. We want to be able: (1) to describe, in words, the ways in which various concepts in electromagnetism come into play in particular situations; (2) to represent these electromagnetic phenomena and fields mathematically in those situations; (3) and to predict outcomes in other similar situations. The overall goal is to use the scientific method to come to understand the enormous variety of electromagnetic phenomena in terms of a few relatively simple laws.

It is essential to our understanding the world around us. The most fundamental processes in nature, from the forces that determine the structure of atoms and molecules to the phenomena of light to nerve impulses in living systems, depend on electric and magnetic fields.

It is fundamental to current and future technologies. Motors, power generation and transmission, electronics, sensors, and communication – both wired and wireless – involve the manipulation of electric or magnetic fields. There are few advances in technology that can be made without the use of electronic circuits or electric and magnetic fields.

It is the simplest example of unification in science. A large and diverse body of observational facts can be explained in terms of a few simple concepts. The phenomena of electricity and magnetism, which appear to be completely different, are shown to be two manifestations of the same physics. The theory requires few if any approximations. Results can be predicted with great accuracy.

It represents the most quantitative mode of inquiry of all the sciences. Of the various ways to approach science, physics in general, and E&M in particular, starts with the smallest set of fundamental assumptions. Quantitative rigor in solving important problems is rewarded by unprecedented agreement with measured results. Chemistry and biology demonstrate different, complementary approaches to dealing with natural phenomena.

Thanks to Tom Greytak & Marc Kastner