Astronomy 1140 -- Autumn 2018 (Prof. Stanek)
Midterm 2 Study Guide (Friday, October 19)
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There will be 50 questions on the Midterm Exam, which will count for
19% of the final grade.

As an option, we allow one "help sheet" (one standard 8.5x11 piece of
paper, both sides can be used) of self-prepared (you can use a
computer) notes to be used during this exam.  Please bring your OSU ID
with you.


Classes to review:

Galileo
Newton's Laws
Newtonian Gravity
Applying Newton's Laws; Tides
Energy
Light
Temperature
Matter
Light and Matter
Telescopes

Key Concepts:

Galileo 
------------------------

(1) Galileo made telescopic observations supporting the heliocentric
    model, especially phases of Venus.


Newton's Laws:
--------------

Three Laws of Motion:

(1) An object remains at rest, or moves in a straight line at constant
    speed, unless acted on by an outside force.
(2) The acceleration of an object is directly proportional to force,
    and inversely proportional to mass.
(3) For every action, there is an equal and opposite reaction.

Law of Gravity:

(4) The gravitational force between masses M and m, separated by
    distance r, is

    F=G(Mm/r^2)

Applying Newton's Laws:
-----------------------

(1) Newton modified and expanded Kepler's Laws of Planetary Motion.
(2) Kepler described how planets move; Newton explained why they move.
(3) Tides are caused by the difference between the Moon's
    gravitational force on different sides of the Earth.

Light:
------

(1) Visible light is just one form of electromagnetic radiation.
(2) Light can be though of as a wave or as a particle (photon).
(3) Light forms a spectrum from short to long wavelengths.

Temperature:
------------

(1) A hot, opaque object produces a continuous blackbody spectrum.
(2) Stefan-Boltzmann Law and Wien's Law

Matter:
-------

(1) Atoms - basic structure
(2) Atoms - energy levels
(3) Isotopes and Radioactivity
(4) Four forces of nature

Spectra:
--------

(1) A hot, transparent gas produces an emission spectrum.
(2) A cool, transparent gas produces an absorption spectrum.
(3) Every type of atom, ion, and molecule has a unique spectrum.
(4) The most abundant elements in the universe are hydrogen and helium.
(5) The radial velocity of an object is found from its Doppler shift.

Telescopes:
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(1) Telescopes use either a lens or a mirror to gather light.
(2) The main purposes of a telescope are to gather light and resolve detail.
(3) Radio and microwave telescopes use a reflecting dish to focus waves.
(4) Telescopes in orbit avoid the distorting effects of the atmosphere.
(5) Ultraviolet, X-ray, gamma ray, and most infrared light is visible
    only from orbit.