Table of Contents

Intro to Astronomy
Definition of Astronomy Electromagnetic Spectrum
Periodic Table
Astronomy Word List
Misconceptions
Questions

Archaeoastronomy
Equitorial Coordinates
Understanding the Seasons

1. Definition of Astronomy: The science which investigates all the matter-energy in the universe: its distribution, composition, physical states, movements, and evolution.
   1. Distribution: The position, arrangement or frequency of matter (or energy) over an area or throughout space.
      1. Note the distribution of matter in the universe, within a galaxy, or our solar system, etc.
   2. Movements: Any condition related to the positional change of matter in space or on a coordinate grid.
      1. Rotation: Period of time a body takes to complete one spin about its axis.
      2. Revolution: Period of time a less massive body takes to complete one orbit around a more massive object
   3. Physical States: The conditions which permit matter to be found as a solid, liquid, gas or plasma.
      1. Solid: Matter with a definite shape, volume, and some fundamental strength.
      2. Liquid: Characterized by free movement of the constiuent molecules among themselves, but without the tendency to separate from one another.
      3. Gas: A fluid that has neither independent shape nor volume, but tends to expand indefinitely.
      4. Plasma: A gas which is ionized which means that it is not electrically neutral. This gas is composed of ions and electrons. The ions (atoms or molecules) which compose the substance have an excess or deficiency of electrons (negative charge) in comparison to the number of protons (positive charge) that they contain.
   4. Composition: The qualitative and quantitative chemical makeup of matter.
      1. Qualitative Example: The sun is composed of hydrogen and helium. Components are merely identified.
      2. Quantitative Example: The sun by volume is composed of 95% hydrogen and 5% helium, but by mass it is composed of 78% hydrogen, 20% helium, and 2% heavier metals. Components are identified by amounts in a numerical fashion.
   5. Evolution: The process of change of the universe in a certain direction. The Steady State (no longer accepted), Big Bang, and Oscillating Universe detail evolutionary sequences for the universe.
      1. Steady State: The universe was always here, always will be here, is infinitely expanding, and appears the same from all locations. Hydrogen is created in the voids between galaxies.
      2. Big Bang: The universe started with a blast and will expand forever.
      3. Oscillating Universe: The universe started with the big bang, but possesses enough mass (gravity) to halt the expansion so that it will one day collapse upon itself.