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Big Bang, Black Holes, No Math ASTR/PHYS 109 Dr. David Toback Lecture 4

Big Bang, Black Holes, No Math ASTR/PHYS 109 Dr. David Toback Lecture 4. Next Topic: Going Small. Finished looking at various things in the universe going from the sizes we know to the VERY big Next we do the very small

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Big Bang, Black Holes, No Math ASTR/PHYS 109 Dr. David Toback Lecture 4

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  1. Big Bang, Black Holes, No MathASTR/PHYS 109Dr. David TobackLecture 4

  2. Next Topic: Going Small • Finished looking at various things in the universe going from the sizes we know to the VERY big • Next we do the very small • Why? If we want to understand the universe we need to know what’s in it and what its made of • Why and how did it get to be the way it is?

  3. Starting out with small things A baseball is a size we know from everyday experience 10 centimeters, or 0.1 meters, or 10-1 meters. About 3 inches

  4. Getting smaller Something smaller you can see with your eyes 0.01 meters, (10-2 m) or 1 cm, or about a 1/3 of an inch

  5. Much smaller A simple dust mite is barely visible with the naked eye Into the realm of biology 10-3 meters or 1 millimeter

  6. A human hair Looking a the side view of a single hair 10-4 meters

  7. Closer still… A single red blood cell 10-5 meters

  8. Further still An HIV virus which is one of the bigger known viruses 10-6 meters

  9. Small Virus A polio virus which is known to be one of the smaller viruses 10-7 meters

  10. The Double Helix A close up of the helical structure of DNA Starting to get into Chemistry 10-8 meters

  11. An Atom • What we’re seeing is the electron “cloud” as it goes around the atom • Kinda like the blades of a fan • The realm of Physics 10-9 meters or 1 nanometer 10 million in a cm

  12. Inside an Atom • Snapshot in time of 2 electrons “orbiting” the nucleus • Atoms are “composite” things, not fundamental 10-10 meters

  13. The Central Part of the Atom • The electrons are outside our field of view 10-11 meters

  14. Homing in on The Nucleus • Still zooming into the center of the atom • The atom is mostly empty space 10-12 meters

  15. The Structure of the Nucleus Can just start to see the “stuff” inside the nucleus The nucleus is not fundamental 10-13 meters

  16. Protons and Neutrons • A carbon atom has 6 protons (blue) and 6 neutrons (grey) • VERY tightly packed 10-14 meters

  17. Inside the Proton • Three quarks inside the proton • Protons are composite • Quarks are fundamental 10-15 meters

  18. Other Fundamental Particles? • Electrons and quarks (as far as we know) are fundamental • Lots of other fundamental particles • Recently discovered the Higgs Boson • We think…

  19. Anti-Matter Each fundamental particle has an anti-matter version which is also fundamental

  20. Stable and Unstable Particles Protons are stable  live forever Neutrons outside a nucleus are unstable  can decay Neutron  Proton + Electron + Neutrino Electron Decay Proton Neutron Neutrino Note that this only happens when Neutrons are by themselves (not in an atom)

  21. Inside an Atom If an atom were the size of a large city, then the neutrons and protons would be the size of a person, and the electrons and quarks would be smaller than a small freckle http://bigbang.physics.tamu.edu/Figures/StolenAnimations/Animation_Atom.mpg

  22. Summary: The “Small” Sciences Matter Molecule Atom Nucleus Protons & Neutrons Quarks u 10-14 m cm 10-9 m 10-10 m 10-15 m <10-19 m Chemistry top, bottom, charm, strange, up, down Atomic Physics Nuclear Physics Electrons <10-19 m Particle Physics

  23. Questions… • How large are electrons and quarks? • We don’t know… that’s what I (and others) do for a living… • What are they “made of”? Are they made of anything? Strings? • Are there other fundamental particles we haven’t discovered?

  24. Prep For Next Time – L4 • Reading: • Required: BBBHNM Unit 2 (Chapters 5-9), will be due Monday • Recommended Reading: • See P3 of http://people.physics.tamu.edu/toback/109/Syllabus.pdf • Pre-Lecture Reading Questions • Unit 1: Stage 1 Revision (if needed), due Monday. Pass/Revise grades posted on CPR later this week • Will post the assignment after class • Unit 2: Stage 1 due Monday • End-of-Chapter Quizzes • If we finished Chapter 3 then End-of-Chapter Quiz 3 (else just Chapter 2)

  25. End of Lecture

  26. Clicker Quiz A muon is observed to decay into an electron and two different neutrinos. Is a muon considered a fundamental particle? • No, because it has the electrons and neutrinos inside it so it can't be fundamental. • Yes, because it isn't composed of electrons and neutrinos, it just decays into them • No, because fundamental particles can't decay

  27. Clicker Quiz Q: What does it mean for an electron to be "stable?" • It is balanced with exactly one proton • Its orbit ring exists in one plane (no wobble) • It has reached minimum size (10-19 m) • Undisturbed, it can go on living forever and ever • They don't appear to be made of anything smaller

  28. Prep For Next Time – L3 • Reading: • BBBHNM: Chap 3 and 4 • Reading Questions: • Two questions from Chapter 3 or the recommended reading • Two questions from Chapter 4 or the recommended reading • eLearning Quizzes • If we finished Chapter 3 then end-of-chapter quiz 3 (else just 2)

  29. Prep For Next Time – L4 • Reading: • BBBHNM: Chap 4 • Reading Questions: • Two questions from Chapters 4 if you didn’t complete already • eLearning End-of-Chapter Quizzes • If we finished Chapter 3 then end-of-chapter quiz 3 (else just 2)

  30. Prep for Today (Is now due) – L4 • Reading: • Required: BBBHNM: Chapter 4 • eLearning End-of-Chapter Quizzes: • End-of-Chapter Quizzes for Chapter 2 • Reading questions: • Two questions for Chapter 3 and two questions for Chapter 4

  31. Prep For Today (is now due) – L4 • Reading: • Required: BBBHNM: Chapter 1-4 • Recommended Reading: • BHOT: Chap. 1-3 • SHU: Chap. 1-2 • TOE: Chap. 1 • Pre-Lecture Reading Questions • Three questions from Unit 1 • End-of-Chapter Quizzes • Chapter 2

  32. Full Set of Readings So Far • Required: BBBHNM: Chap 1-4 • Recommended: • BHOT: Chap. 1-3 • SHU: Chap. 1-2 • TOE: Chap. 1

  33. Other Fundamental Particles? • Electrons and quarks (as far as we know) are fundamental • Lots of other fundamental particles • There is also anti-matter • Each fundamental particle has an anti-matter version which is fundamental

  34. Prep For Next Time – L4 • Reading: • BBBHNM: Chap 5 • Pre-Lecture Reading Questions: • Two questions from Chapter 5 • End-of-Chapter Quizzes • If we finished Chapter 3, then do 3 (if not, just 2)

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