A Brief History Of Time: Journal Entry 5

Chapter 5 (Pg 65-81) In this chapter, Stephan Hawking talks about Aristotle and his beliefs on how the world is made of Fire, Water, Earth, Air and that matter is continuous, but some Greeks like Democritus disagreed. This argument continued for centuries until Einstein wrote a paper on the Brownian motion, the effect of atoms of liquids colliding with dust particles. I read about the discoveries of the election, proton, neutron and the entire structure of the atom. I learned about quarks (the particles that make up a proton, neutron, & electron), a positron, an anti-electron, and that every particle has an antiparticle. I also read about how in quantum mechanics the forces or interactions of matter particles are carried by particles of an integer spin 0, 1, or 2, the three of four categories of force carrying particles (gravity, weak nuclear force, & electromagnetic force), the Weinberg-Salem Theory (a theory that's about weak nucler force), and the fourth force carrying particle strong nuclear force, I learned that confinement prevents you from seeing an isolated quark or gluon. I read about whether a proton or neutron can decay (but they can't since they live or function for more than 1 with thirty zeros after it years. I also read about how people believed that the law of physics obeyed the symmetries C, that the laws are the same for particles & antiparticles, T, that if you reverse the direction of motion in particles & antiparticles the system should go back to what it was at earlier times, & P, that the laws are the same for any situation and its mirror image. At the end he starts talking about Black Holes, which is the center of focus for the next chapter.