Energy from Stars: Teacher's Guide
Outline of concepts to be presented
While viewing the Earth from space, we propose that our planet is a unique, complex, dynamic system; where water naturally exists as a solid, liquid, and a gas; which supports an incredible diversity of life. Closer to home, we discuss the fact that energy is required by these life-forms (carbon cycle), and energy also drives the weather that supplies the water essential for life. That energy comes from an external source -- the sun. But the sun has been providing that energy for billions of years. How can it radiate so much energy for so long?
With a reminder that the sun is a star, we explore the theory of stellar formation. We ponder whether gravity could provide this energy, but realize that the collapse of the nebula would be 100 million years, maximum. Then, we explore fusion, the rate that matter is converted into energy, and the "life span" of stars. The link is made to Einstein's famous equation (energy = mass x speed of light squared), and a nuclear bomb.
We then finish the "life-cycle" of a solar mass star and the formation of carbon. Large stars can produce iron, but where do the heaviest elements come from? This leads us into the final stages of the largest stars; supernovae producing neutron stars, pulsars, and black holes. Then, a comparison is made at the other end of the size range, with Jupiter-sized planets and a red dwarf. The program ends by applying this concept to a nova cycle in a binary star system.
- energy from the sun drives our weather and the carbon cycle.
- the sun converts mass to energy in a process called fusion.
- stellar formation and evolution.
Connecting to the Classroom
This program works well integrated into a unit on any of the above concepts. It can be adapted to serve as an introduction to your unit, or as a summary or application of the unit. This program was designed to be integrated into a high school integrated science program, and supports the Wisconsin Model Academic Standards for Science.
- knowledge of atomic structure
- knowledge of the carbon cycle (sun's energy into plants, plants to animals, etc.)
Vocabulary: some of the words the students will likely encounter
- carbon cycle
- star (white dwarf, red dwarf, giant, super-giant, neutron star, pulsar, black hole)