Part 2/9:
During Einstein's lifetime, the understanding of matter was limited to classical physics and gravity. But modern physics has uncovered an intricate world of subatomic particles—electrons, quarks, neutrinos, and numerous others—far more diverse and complex than anything Einstein could have imagined.
This proliferation of particles presents a daunting challenge: how do we reason about the vast diversity of matter around us with a single, unifying framework? The answer, many believe, lies in theories that push the boundaries of traditional physics—some of which are considered "crazy."