Science Introduction to the Life Cycle of Stars

Overview Stellar evolution is the theory of the life cycle of stars. Scientists observe many different stars at various stages, starting with the earliest condensations from clouds of nebular gas and dust. Once the temperature is high enough in a star’s core, hydrogen atoms begin nuclear fusion to helium. Eventually, hydrogen is depleted in the […]

Science Review of the Supernova

Overview A supernova (plural supernovae) occurs when a star over twice the mass of the sun explodes. It is theorized to occur near the end of the huge star’s life, before the star collapses into a black hole. According to astrophysicists, chemical elements that were heavier than hydrogen and helium were formed in nuclear reactions […]

Math Review of More Fun with Tau

Overview The quantity represented by the Greek letter tau (6.283185…) is the proportion of the circumference of a circle to its radius. The use of tau simplifies the relationships between angles and circles. These relationships underlie other branches of mathematics and applications to science. Special Angles and Tau The relationship of tau and the circle is […]

Math Review of Pi and Tau

Overview The number represented by the Greek letter pi (3.14159…) is one of the most famous irrational numbers in mathematics. It is the ratio of the circumference of a circle to its diameter. The number represented by the Greek letter tau (6.283185…) is the ratio of the circumference of a circle to its radius. It […]

Biology Review of Life in a Coral Reef

Overview Coral reef environments are among the most biologically diverse and productive marine habitats of the ocean ecosystem. The plants and animals live in balance and mutual dependence with one another. However, these fragile environments are at risk by predators and destruction. The Coral Reef Environment Coral reefs exist in warm, tropical, shallow salt water, […]

Biology Review of Plankton

Overview Plankton include many organisms that live on near the surface of water, and float with the currents. There are types of freshwater plankton that live in lakes, while saltwater plankton live in oceans and saltwater lakes. They are at the bottom of the food chain, and are a rich source of nutrients for many […]

Biology Review of Wetlands

Overview Wetlands are ecosystems where the land is covered by water or near water. The water may be standing or flowing slowly, or the soil may be moist enough for at least part of the year that wetland plants and animals use it as their habitat. The salt content of the water is important to […]