Lecture 2. How the Sun shines
Light and the Electromagnetic spectrum
Types of Energy: electromagnetic, gravitational, nuclear (strong)
Chemical energy (burning) is electromagnetic: Can only power the Sun for a few thousand years
Gravitational energy (slow contraction) can only power the sun for 30 million years
Nuclear fusion converts matter to energy: Einstein E=mc^2. This can power the Sun for 10 billion years
Hydrostatic equilibrium: stars are a stable balance between the outward pressure of the hot gas (trying to expand) and the inward pressure from gravity (trying to contract)

Things to look at
Light and the Electromagnetic spectrum
An introduction to light
Review matter and energy and atomic structure
Suns power source .
hydrostatic equilibrium
Pages 95-101 in Kuhn
Pages 337-347 in Kuhn
For those who like to do it themselves, here is everything you need to work out how long the sun would live if it were powered by normal burning