Princeton University
A Teacher's Guide to the Universe
Astronomers only observe four percent of the universe as the rest hides in darkness. The size, shape, and movement of the universe are the focus for an long-term high school unit. Its 43 lessons include hands-on experiments, direct...
NASA
Measuring Dark Energy
You're only 10 minutes late? Do you know how much the universe has expanded in those 10 minutes? Scholars graph supernovae based on their redshift and see if the results verify Hubble's Law. If it does confirm it, the universe is...