Daniel ast103_01a: Our Place in the Universe: Supplement
- 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.
- This wrong unless some silly qualification.
comoving radius of the observable universe = 14.25 Gpc = 46.48 Gly (cosmic present value).
- The solar radius is 109 Earth radii
(see Wikipedia: Sun).
- If the Sun were grapefruit, the
Earth
would be the ball point of
a ballpoint pen.
- 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.
-
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.
- 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.
- All below is for a daniel_ast103_10.html.
- Videos:
- 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
- Aurora Australis from near McMurdo Station and Scott Base
Nifty to look at, but not terribly informative. OK for classroom.
- Casino Royal
- 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.
- albedo:
- aurora
- convection:
Atmospheric circulation,
Hadley cell,
Jovian band structure
Ferrell cell,
polar vortices,
Venusian circulation
- carbon cycle:
carbon (C),
carbon dioxide (CO_2).
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- Earth:
diffuse sky radiation: Why the
sky is blue,
Earth's atmosphere,
solar wind,
stratosphere.
- magnetosphere:
Earth's magnetic field,
Earth's magnetosphere.
- greenhouse effect:
greenhouse gas
-
- climate:
anticyclones,
Coriolis effect,
weather.
- prevailing winds:
tropical east trade winds,
Westerlies,
polar easterlies,
cyclones,
anticyclones,
tropical cyclones,
hurricane.
- water cycle
- climate change:
global warming (AKA anthropogenic climate change)
-
- Sun: Life phases,
Sun's life phases
- ice age:
- Milankovich cycles
Earth's axial tilt,
current ice age (Quaternary ice age),
current ice age,
interglacial,
glacial period,
Quaternary glaciation,
- outgassing:
atmospheric escape,
impactors
- Moon:
Mercury,
Mercury's atmosphere,
Moon's atmosphere.
- Mars:
Martian atmosphere,
Martian climate,
Martian dust,
Martian seasons.
- Martian polar caps
- 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,
- ozone
O_3
ozone (O_3)
ozone layer
- Penulum:
- solar wind
- stratosphere
- volcano:
aerosol,
impactors,
particulates.