Certain areas of physics attempt to answer the domanda about how the universe was constructed and it is powerful enough to investigate the Universe and measure many parameters to determine the exact fate of the Universe...Physics (incl maths) are the studies that really help human grasp the awesomeness of the Universe...
Everything. It's so interesting, there's so much to learn and so much we still have to discover. It's kind of like scientific magic, lol. I especially Amore quantum physics - protons, electrons, neutrons, particles, quarks, anti-matter, anti-particle, electrons... What's not to Amore about physics? It's just so fascinating!