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HSC Physics

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  1. Module 1: Kinematics
    1.1 Motion in a Straight Line
  2. 1.2 Motion on a Plane
  3. Module 2: Dynamics
    2.1 Forces
  4. 2.2 Forces, Acceleration and Energy
  5. 2.3 Momentum, Energy and Simple Systems
  6. Module 3: Waves and Thermodynamics
    3.1 Wave Properties
  7. 3.2 Wave Behaviour
  8. 3.3 Sound Waves
  9. 3.4 Ray Model of Light
  10. 3.5 Thermodynamics
  11. Module 4: Electricity and Magnetism
    4.1 Electrostatics
  12. 4.2 Electric Circuits
  13. 4.3 Magnetism
  14. Module 5: Advanced Mechanics
    5.1 Projectile Motion
  15. 5.2 Circular Motion
  16. 5.3 Motion in Gravitational Fields
    2 Topics
  17. Module 6: Electromagnetism
    6.1 Charged Particles, Conductors and Electric and Magnetic Fields
  18. 6.2 The Motor Effect
    1 Topic
  19. 6.3 Electromagnetic Induction
  20. 6.4 Applications of the Motor Effect
    1 Topic
  21. Module 7: The Nature of Light
    7.1 Electromagnetic Spectrum
    3 Topics
  22. 7.2 Light: Wave Model
  23. 7.3 Light: Quantum Model
    2 Topics
  24. 7.4 Light and Special Relativity
  25. Module 8: From the Universe to the Atom
    8.1 Origins of the Elements
    5 Topics
  26. 8.2 Structure of the Atom
    3 Topics
  27. 8.3 Quantum Mechanical Nature of the Atom
    2 Topics
  28. 8.4 Properties of the Nucleus
    2 Topics
  29. 8.5 Deep Inside the Atom
    4 Topics
Lesson 25, Topic 4
In Progress

Expansion Evidence

Lesson Progress
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  • Light spectrum shift
    • i.e. Doppler effect
    • Occurs in all directions
    • Everything moving away
  • Helium-Hydrogen ratio
    • 25% He, 75% H (actual)
    • Matches Big Bang predictions
  • Cosmic background radiation
    • Gamow – predicted ‘background radiation’ from Big Bang
    • Penzias, Wilson – accidentally found/proved radiation
  • Not enough hot stars
  • Presence of radio galaxies, blue stars
  • Connection btwn. particle physics, cosmologies

Edwin Hubble

  • Californian Astronomer
  • During the 1920s, Hubble pioneered a technique to find the distance to other galaxies and showed that they were beyond our own
  • Discovered 20+ galaxies
  • Examining the light from stars in those galaxies, Hubble found familiar spectra of known elements (e.g. hydrogen, helium) but found all spectra were redshifted
  • Applied doppler shift to galaxies
    • Everything moving away
    • Further away = Moving away faster (found greater red shift)
    • Mathematically direct relationship
  • The reason behind this redshift is not that all objects are moving through the universe away from us, but rather that the universe itself is expanding, stretching the wavelength of travelling light.