Introduction to Astronomy


I. In the beginning...

i. Observing the sun: shadow stick astronomy:
a) Daily observations -- sunrise, sunset, noon (shortest shadow).

b) Longer term observations -- equinoxes, solstices, defining the year.

c) Stars in the Heavens -- perpetual apparition, seasonal changes.

ii. Alignment of neolithic structures:

Stonehenge; Egyptian pyramids; PreColumbian alignments.

iii. Mapping the sky - setting up an observatory:

Babylonian tables; celestial poles, celestial equator, right ascension, declination.

iv. The changing sky: Eclipses, planets, geocentrism and Ptolemy;

Greek models - successes and failures.

Observations vs. faith -- falsifiability.


II. Revolution "eppur si muove"

 i. Copernicus and the heliocentric model:
Unraveling the retrograde loop; eliminating order ambiguity;
establishing the scale of the solar system.

ii. Kepler breaks free of Ptolemy:

Ellipses and K's three laws.

iii. Galileo - objective support for heliocentrism:

Telescopic observation of the sky; phases of Venus; Jupiter's moons - Jovi-centrism.

iv. Newton and the first universal law:

The Science of Mechanics - Aristotle to Galileo; position, velocity, acceleration, force; three laws; circular motion.

v. Law of gravity

On Earth and in solar system; Moon, apple, and universality.

vi. Universal laws of physics.

III. Stars

 i. Measuring the stars:
Distance, magnitude, spectrum, binary orbits.
Absolute magnitude, luminosity, mass.

ii. Putting it together:

Mass - luminosity relationship;
H-R diagrams for local stars and for clusters.

iii. Stellar models:

Gravity against pressure; heat rises; H bomb and "gravity bomb" energy conversion; the ideal gas; thermal equilibrium.

iv. Stellar Evolution:

Birth of a solar mass star and the associated solar system; main sequence lifetime calculation; death of a solar mass star.

v. Death of a star:

White dwarfs and the Chandrasekhar limit; supernovae and neutron stars.

vi. The black hole:

Gravity and the principle of equivalence; bending the path of light; the black hole as an evolutionary endpoint.

How to find a stellar black hole.

.IV. Cosmology

 i. Our galaxy:
It shape and size; its spiral structure; the mystery of its mass.

ii. Galaxies afar:

The problem with finding distance; more missing mass; supermassive black holes in galactic centers.

iii. Cosmology:

Galactic red shifts and the Hubble law; the distance ladder; the Big Bang and microwave background radiation; geometry and evolution of the universe.



Physics 160