Hi there,
If you are taking the lab component of Astronomy as well (which is true for most of you), you need to complete (independently) the laboratory "experiments" from the packet available in the book store.
There are, I believe, 8 of these. You must complete 7, however I'm going to allow a substitution of 3 of my own labs (which I can provide by next Tuesday).
You can write the labs up in any order. I would honestly prefer that you submit them all at once, part-way through the course. I would take a look at them and tell you if a re-working of any of them would be beneficial (to help raise a grade).
The grade of this lab course will come from the graded reports, with one re-write of the entire packet being permitted before Summer Session I ends.
Make sense? Hope so!
-Sean
Wednesday, June 5, 2013
Tuesday, June 4, 2013
For Quiz 1
Star chart basics
Asterism vs. constellation
Brightest objects
Ecliptic-apparent path of sun
Zodiac constellations
3000 stars visible to naked eye
Finding Polaris
Big Dipper and Little Dipper
Cassiopeia
Arcturus ("follow the arc to Arcturus")
Summer Triangle (Vega, Altair, Deneb)
Northern Cross / Cygnus
How do we know that the Earth is "spherical"?
West and east backward on star chart?
Units - m, kg, s -- basics of the history of each
Speed of light: 300,000,000 m/s (roughly) or 186,000 miles/sec or around 7 times around Earth's equator in 1 second
Light-year
Light-minute
Light-second
(All astronomical units of length)
Asterism vs. constellation
Brightest objects
Ecliptic-apparent path of sun
Zodiac constellations
3000 stars visible to naked eye
Finding Polaris
Big Dipper and Little Dipper
Cassiopeia
Arcturus ("follow the arc to Arcturus")
Summer Triangle (Vega, Altair, Deneb)
Northern Cross / Cygnus
How do we know that the Earth is "spherical"?
West and east backward on star chart?
Units - m, kg, s -- basics of the history of each
Speed of light: 300,000,000 m/s (roughly) or 186,000 miles/sec or around 7 times around Earth's equator in 1 second
Light-year
Light-minute
Light-second
(All astronomical units of length)
SI Units!
Mass is measured based on a kilogram (kg) standard.
Length (or displacement or position) is based on a meter (m) standard.
Time is based on a second (s) standard.
How do we get these standards?
Length - meter (m)
- originally 1 ten-millionth the distance from north pole (of Earth) to equator
- then a distance between two fine lines engraved on a platinum-iridium bar
- (1960): 1,650,763.73 wavelengths of a particular orange-red light emitted by atoms of Kr-86 in a gas discharge tube
- (1983, current standard): the length of path traveled by light during a time interval of 1/299,792,458 seconds
That is, the speed of light is 299,792,458 m/s. This is the fastest speed that exists. Why this is is quite a subtle thing. Short answer: the only things that can travel that fast aren't "things" at all, but rather massless electromagnetic radiation. Low-mass things (particles) can travel in excess of 99% the speed of light.
Long answer: See relativity.
Time - second (s)
- Originally, the time for a pendulum (1-m long) to swing from one side of path to other
- Later, a fraction of mean solar day
- (1967): the time taken by 9,192,631,770 vibrations of a specific wavelength of light emitted by a cesium-133 atom
Mass - kilogram (kg)
- originally based on the mass of a cubic decimeter of water
- standard of mass is now the platinum-iridium cylinder kept at the International Bureau of Weights and Measures near Paris
- secondary standards are based on this
- 1 u (atomic mass unit, or AMU) = 1.6605402 x 10^-27 kg
- so, the Carbon-12 atom is 12 u in mass
Volume - liter (l)
- volume occupied by a mass of 1 kg of pure water at certain conditions
- 1.000028 decimeters cubed
- ml is approximately 1 cc
Temperature - kelvin (K)
- 1/273.16 of the thermodynamic temperature of the triple point of water (1 K = 1 degree C)
- degrees C + 273.15
- 0 K = absolute zero
For further reading:
>
In addition, we spoke about the spherocity of the Earth and how we know its size. I've written about this previously. Please see the blog entries below:
Celestial Sphere Sites
Celestial sphere sites
Jack Horkheimer, for your interest. Not related to the Celestial Sphere stuff.
Useful stuff.
Useful Apps for smartphones or tablets:
sunrisesunset.com
Google Earth
Moon globe
Exoplanet
NASA
APOD
SkyWalk
Planets
SkyWeek
Distant Suns
Moon
Night Sky
Sky Map
FaceBook feeds:
From Quarks to Quasars
Sky and Telescope magazine
Science is Awesome
Misc resources:
Astronomy magazine
Sky and Telescope magazine
Smithsonian Air and Space Museum
Smithsonian Udvar-Hazy Air and Space Museum annex
Good sites (a very, very brief start):
Topics
Night Chapter Topic(s)
1 1 Night sky, Time, Patterns I (asterisms, constellations), Celestial Sphere
2 2 Patterns II, History of Astronomy, Astrology (whaaaaa?)
3 2 Relevant Physics
4 3 Light and Telescopes
5 4-5 Planetary Systems, Planets I
6 6-7 Planets II
7 8-9 The Sun and other Stars
8 10-11 The Life of Stars
9 13 Cosmology, etc.
1 1 Night sky, Time, Patterns I (asterisms, constellations), Celestial Sphere
2 2 Patterns II, History of Astronomy, Astrology (whaaaaa?)
3 2 Relevant Physics
4 3 Light and Telescopes
5 4-5 Planetary Systems, Planets I
6 6-7 Planets II
7 8-9 The Sun and other Stars
8 10-11 The Life of Stars
9 13 Cosmology, etc.
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