Spring 2026 Course Search

How does influence travel from one thing to another? In Newton’s mechanics of particles and forces, influences travel instantaneously across arbitrarily far distances. Newton himself felt this to be incorrect, but he did not suggest a solution to this problem of “action at a distance.” To solve this problem, we need a richer ontology: The world is made not only of particles, but also of fields. As examples of the field concept, we study the theory and applications of the electric field and the magnetic field.

All but a handful of the objects you see in the night sky are stars in our Galaxy, the Milky Way. Although we know about these stars only from studying their light, we know today that they are not just points of light, but large, gravitationally‐bound balls of plasma governed by the laws of physics. Stars, together with dust, gas, and dark matter, are found in larger structures – galaxies. In turn, galaxies, are located in even larger structures called galaxy groups and galaxy clusters.