Daniel ast103_01a: Our Place in the Universe: Supplement


  1. This question must be posed counterfactually. Assume an infinite static universe that magically came into existence out of nothing 14 billion years ago. Then there is the right answer.
  2. This wrong unless some silly qualification. comoving radius of the observable universe = 14.25 Gpc = 46.48 Gly (cosmic present value).
  3. The solar radius is 109 Earth radii (see Wikipedia: Sun).
  4. If the Sun were grapefruit, the Earth would be the ball point of a ballpoint pen.
  5. Amount over rate problem A/R=t to exhaustion. So (10**11 stars)/(1 star/s) = 10**11 s and (10**11 s)*(1 year/3*10**7 s) = 3*10**3 years.
  6. In this question universe means observable universe since the unobservable universe is of unknown size and may be infinite. Are they counting dwarf galaxies? What is their lower cut-off. But dwarf galaxies have relatively few stars, and so 10**22 stars in the observable universe.
  7. Astronomy has always played a role in timekeeping (time of day, time of lunar month, and more elaborate things too) and navigation (geographic directions and more elaborate things too).
    Newtonian physics was "a" basis for the Industrial Revolution (c.1750--c.1850), but not "the" basis.
  8. All below is for a daniel_ast103_10.html.

  9. Videos:
    1. Earth | Time Lapse View from Space, Fly Over | NASA, ISS or on YouTube (Wikipedia: YouTube) Earth | Time Lapse View from Space, Fly Over | NASA, ISS with poorer quality. Pretty spectacular. A time-lapsed set of images from the International Space Station (ISS). The astronauts see the rolling by of the Earth much more slowly, and, of course, they don't see aurora and thunderstorms all the time. This is how Superman or Zeus might see world. Ordinarily too long for the classroom with a long load time, but it might make a good opening or closing video
    2. Aurora Australis from near McMurdo Station and Scott Base Nifty to look at, but not terribly informative. OK for classroom.
    3. Casino Royal
    4. In agua caliente I think those are just bits of paper. They should have about the same density as water so that they would float neutrally, neither rising or sinking in still water. The Spanish make the best convection videos. Short enough for classroom.
  10. albedo:
  11. aurora
  12. convection: Atmospheric circulation, Hadley cell, Jovian band structure Ferrell cell, polar vortices, Venusian circulation
  13. carbon cycle: carbon (C), carbon dioxide (CO_2).

  14. Earth: diffuse sky radiation: Why the sky is blue, Earth's atmosphere, solar wind, stratosphere.
  15. magnetosphere: Earth's magnetic field, Earth's magnetosphere.
  16. greenhouse effect: greenhouse gas
  17. climate: anticyclones, Coriolis effect, weather.
  18. prevailing winds: tropical east trade winds, Westerlies, polar easterlies, cyclones, anticyclones, tropical cyclones, hurricane.
  19. water cycle
  20. climate change: global warming (AKA anthropogenic climate change)
  21. Sun: Life phases, Sun's life phases
  22. ice age:
  23. Milankovich cycles Earth's axial tilt, current ice age (Quaternary ice age), current ice age, interglacial, glacial period, Quaternary glaciation,
  24. outgassing: atmospheric escape, impactors
  25. Moon: Mercury, Mercury's atmosphere, Moon's atmosphere.
  26. Mars: Martian atmosphere, Martian climate, Martian dust, Martian seasons.
  27. Martian polar caps
  28. Venus: Future of the Earth, runaway greenhouse effect Venusian atmosphere, Rampino, M. R. & Caldiera, K. 1994, ARAA, 32, 83-114, The Goldilocks Problem: Climatic Evolution and Long-Term Habitability of Terrestrial Planets, Wikipedia: Future of Earth: Climate Impact,
  29. ozone O_3 ozone (O_3) ozone layer
  30. Penulum:
  31. solar wind
  32. stratosphere
  33. volcano: aerosol, impactors, particulates.