Research mines to discover minerals and the best ways to get them out.
As a Theoretical Physicist, you’re a professional thinker. Instead of doing experiments like most Scientists, however, you tackle theoretical questions about nature, the universe, particles, matter, and rainbows. You try to answer conundrums like “Why is matter heavy?” and “Why is the universe still growing?”
You may spend lots of time with other Scientists. You’re familiar with other kinds of science, especially experimental physics, but most importantly, you’re really, really good at math. Your brand of science is fairly unique because instead of doing experiments in a lab coat, you use mathematical models to answer your questions.
If you work at a university (which is where many Theoretical Physicists work), you spend at least some of your time teaching. However, regardless of where you work, you spend your days reading the work of other Theoretical Physicists, thinking about the solutions they recommend, and coming up with mathematical models to explain why the universe works the way it does.