NOTE: This site was damaged, but is now working again. If you find glitches, please let me know. I'm sorry for the inconvenience.
T. Arny
arny@nova.astro.umass.edu
Solving Distance-Velocity-Time Problems
Powers of Ten Tutorial
Comparing Sizes
Gravity and Escape Velocity Tutorial
Seasons/Daylength
Atoms
Orbits
The Outer Planets and density as a probe
Measuring Properties of Stars
Galaxies