Curated OER
The Right Ratio of Rest: Proportional Reasoning
Students see how NASA scientists are studying the circadian timing system to improve astronaut's physical and mental tasks while working in space. They demonstrate how fractions, decimals, and percents are related.
Encyclopedia of Earth
Encyclopedia of Earth: Health Effects of Light Pollution
Article discusses the impact of light pollution on the health of human beings as well as on plants and wildlife. (Updated July 18, 2012)