An Ancient Universe: How Astronomers Know the Vast Scale of Cosmic Time . Appendix Two . Activities for Teaching about the Age of the Universe and Its Contents . Below are a few activities that you can do with your students to show them how science works and how we have come to know about the age and evolution of the universe. ... Cosmic Calendar * Cosmic Calendar : www.astrosociety.org/education/astro/act2/cosmic.html . ... www.astrosociety.org/education/activities/astroacts.html . ...