This 10-minute video lesson provides a basic introduction to light and electromagnetic radiation. [Cosmology and Astronomy playlist: Lesson 68 of 85]

This 11-minute video lesson works through a calculation for K-Ar dating (it is good to have some prior experience with e and logarithms to understand). [Cosmology and Astronomy playlist: Lesson 80 of 85]

This 13-minute video lesson ponders how we get calories from the land and the limits of human population density. [Cosmology and Astronomy playlist: Lesson 83 of 85]

This 7-minute video lesson looks at the lifecycle of massive stars (stars with masses greater than 9 times the sun). [Cosmology and Astronomy playlist: Lesson 27 of 85]

This 13-minute video lesson looks at how changes in Earth's rotation can effect Earth's seasons and climate. It discusses Milankovitch Cycles, Precession, and Obliquity. [Cosmology and Astronomy playlist: Lesson 71 of 85]

This 6-minute video lesson looks at the idea of Pangaea and some of the evidence behind it. [Cosmology and Astronomy playlist: Lesson 56 of 85]

This 7-minute video lesson explains what parallax is and how it is used to determine distances between stars. [Cosmology and Astronomy playlist: Lesson 21 of 85]

This 8-minute video lesson defines parsec a unit of distance used in astronomy. [Cosmology and Astronomy playlist: Lesson 25 of 85]

This 8-minute video lesson looks at plate tectonics and the difference between crust and lithosphere. [Cosmology and Astronomy playlist: Lesson 43 of 85]

This 13-minute video lesson looks at plate tectonics and the evidence of plate movement. [Cosmology and Astronomy playlist: Lesson 45 of 85]

This 12-minute video lesson continues to explore plate tectonics. It covers the geological features of divergent plate boundaries. [Cosmology and Astronomy playlist: Lesson 46 of 85]

This 6-minute video lesson continues to explore plate tectonics. It covers the geological features of convergent plate boundaries. [Cosmology and Astronomy playlist: Lesson 47 of 85]

This 6-minute video lesson coninues to look at plate tectonics. It discusses plates moving due to convection in mantle. [Cosmology and Astronomy playlist: Lesson 48 of 85]

This 11-minute video lesson looks at Potassium-Argon (K-Ar) dating and it can be used to date very old volcanic rock and the things that might be buried in between. [Cosmology and Astronomy playlist: Lesson 79 of 85]

This 12-minute video lesson clarifies the effect of axial precession on the calendar and the date of perihelion and aphelion. [Cosmology and Astronomy playlist: Lesson 73 of 85]

This 2-minute video lesson provides a correction to the previous video about quasars. [Cosmology and Astronomy playlist: Lesson 36 of 85]

This 9-minute video lesson discusses quasars. [Cosmology and Astronomy playlist: Lesson 35 of 85]

This 17-minute video lesson discusses the radius of the observable universe. [Cosmology and Astronomy playlist: Lesson 8 of 85]

In this 11-minute video lesson Sal makes random predictions for the year 2060. [Cosmology and Astronomy playlist: Lesson 85 of 85]

This 10-minute video discusses redshift and the Doppler Effect. [Cosmology and Astronomy playlist: Lesson 10 of 85]