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  • Writer's picturebruce yu

#5 A Brief History of Time - Elementary particles and the forces of nature

Updated: Jul 31

Chapter 5:

  1. Aristotle VS. Democritus

  2. Aristotle believes all the matter in the universe was made up of 4 elements- earth, air, fire, and water

  3. Democritus holds that matter was made of various different kinds of atoms (atom means indivisible in Greek)

  4. Brownian motion

  5. In 1905, Einstein pointed out that Brownian motion can be explained by the irregular random motion of small particles of dust suspended in the liquid.

  6. Quarks

  7. Protons and electrons are made of quarks

  8. There can be an entire world made of antiparticles ( mostly antiquarks)

  9. Force carrying particles

  10. Gravitational force

  11. Electromagnetic force

  12. Weak nuclear force

  13. Strong nuclear force

  14. Combined symmetry CPT







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