Intro: Mr. Toastmaster, distinguished guest, and fellow Wavemakers of planet Earth: When ancient peoples looked at nature, they ascribed personalities to the forces infulencing their lives. These ideas grew into complex mythologies that tried to explain why things are as they are. With our modern science such explainations seem silly and largely useless.
However, many of the explainations that modern science provides seem distant from our everyday lives. In such cases, a familiar analog can greatly aide understanding. Let us take for example, the life of a Star.
II. Learning to Shine
A. Getting started
1. Material from dead stars, accumulated over long time spans, much as dust might accumulate in a corner, orbits in the galactic plane
2. Gravitational attraction pulls it into clumps, often triggered by nearby energy releases or encounters with massive objects
B. Ignition
1. Pressue from infalling matter
2. IR radiation released from motion
3. At a certain point of pressure and temperature, H begins to fuse. 4H+ --> 1He+, 2 positrons, 2 neutrinos, and energy
4. This energy is Light, heat, UV, and other frequencies
5. Outward pressure slows collapse, equilibrium is reached
III. Working for a Living
A. Falling in line
1. As the Hydrogen burns, the haze of gasses around it thin, and the star's characterisics become clear
2. Brightness: a function of size, as the more surface area, the more light can be emitted.
3. Color: a function of temperature; hotter= higher frequency, ROY G BIV
IV. Mid-life Crisis and Retirement
A. Post-Hydrogen Fusion
1. Helium
2. Post-Helium, only if larger than about 8 solar masses
a. Carbon, Oxygen
b. Neon & Magnesium or Silicon & Sulfur
c. Iron
B. Collapse
1. Small star collapse
a. Not enough pressure to fuse Carbon or Oxygen
b. He fusion pushes remaining H outward, cooling
c. Red Giant
d. Envelope becomes Planetary Nebula
e. Core becomes a White Dwarf
2. Large star
a. Iron Core Collapse
b. 5000 mi diameter to 12 mi diameter in about 1 second
c. Outer shell, uncollapsed, is pushed out by this energy, impacts form heavy elements
d. Outshines whole galaxies
e. Leaves a remnant
i. Neutron Star
ii. Black hole