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History of Subatomic Physics

History of Subatomic Physics

A brief history of subatomic physics from J. J. Thomson to Paul Dirac and Carl David Anderson

Arash Badie Modiri

May 12, 2015
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  1. J.J. Thomson (1897) "Cathode Rays", The Electrician 39, 104 Retrieved

    via Google Books: https://books.google.com/books? id=vBZbAAAAYAAJ&pg=PA104&hl=en
  2. Discovery of Corpuscles: J. J. Thomson and Cathode Rays A

    thousand times smaller than hydrogen atoms. It’s mass does not depend on source atom.
  3. J. J. Thomson and Cathode Rays One can deflect cathode

    rays by a magnetic field. What about an electric field?
  4. Where do these “Corpuscles” things come from? From the cathode

    or the tube? Are they from inside atoms? What does it even mean?
  5. Theory of Atomic Disintegration: Early Days of Nuclear physics Rutherford

    and Soddy: Thoron emitted from Thorium. Pierre and Marie Curie: Isolation of Radium and Polonium. William Crookes: Uranium transforms to Uranium-X
  6. I accumulated alpha in a jar, but all I got

    was Helium and electric charge…
  7. ” Geiger–Marsden Experiment It was quite the most incredible event

    that has ever happened to me in my life. It was almost as incredible as if you fired a 15-inch shell at a piece of tissue paper and it came back and hit you.
  8. Transmuting Matter Nitrogen + Alpha → Oxygen + Hydrogen nuclei

    Hydrogen nuclei were a part of nitrogen nuclei (and probably other nuclei)
  9. Q: How to link experiment to theory? A: Study one

    and marry the other. Sir Ralph Howard Fowler
  10. I also don’t like how Schrödinger’s quantum mechanics are not

    quite compatible with Einstein's special relativity.
  11. There you go. I fixed your equations in the most

    mathematically beautiful way possible. It’s so beautiful I want to engrave it on my grave. But I had to assume that there exists a particle, never seen before, with same general physical properties as electron only with a positive charge…
  12. “Found your particle”, said Carl David Anderson a few years

    later in a paper titled “The Positive Electron” published in Physical Review for which he won a Nobel prize in physics. Photo retrieved from: https://commons.wikimedia. org/wiki/File:PositronDiscovery.jpg