Flux

• as apparent brightness
• as energy flow

Inverse Square Law for Flux

• geometry
• role of energy conservation

Spectroscopy & Kirchhoff's Rules

• Kirchoff diagrams here and here
• solar spectrum imaged and plotted

Matter Overview

• Chemical elements
• Atom components

Theory of Spectra: the Quantum Atom

• Balmer spectra: in laboratory, in space--seagull nebula
• de Broglie: matter waves
• Bohr model of the atom
• Hydrogen spectrum, binding energy