And how do we know?. Foundations of Astronomy. Part 1: THE SKY.1. Here and Now.2. A User’s Guide to the Sky.3. Origins of Modern Astronomy.5. Atoms and Spectra.8. The Sun.9.
@riseup.netAnd how do we know?. Foundations of Astronomy. Part 1: THE SKY.1. Here and Now.2. A User’s Guide to the Sky.3. Origins of Modern Astronomy.5. Atoms and Spectra.8. The Sun.9.