Category: 5. Radiation & Spectra

Collaborative Group Activities

For Further Exploration Articles Augensen, H. & Woodbury, J. “The Electromagnetic Spectrum.” Astronomy (June 1982): 6. Darling, D. “Spectral Visions: The Long Wavelengths.” Astronomy (August 1984): 16; “The Short Wavelengths.” Astronomy (September 1984): 14. Gingerich, O. “Unlocking the Chemical Secrets of the Cosmos.” Sky & Telescope (July 1981): 13. Stencil, R. et al. “Astronomical Spectroscopy.” Astronomy (June 1978): 6. Introductions to Quantum Mechanics Ford, Kenneth. The…

Learning Objectives By the end of this section, you will be able to: The last two sections introduced you to many new concepts, and we hope that through those, you have seen one major idea emerge. Astronomers can learn about the elements in stars and galaxies by decoding the information in their spectral lines. There…

Learning Objectives By the end of this section, you will be able to: We can use Bohr’s model of the atom to understand how spectral lines are formed. The concept of energy levels for the electron orbits in an atom leads naturally to an explanation of why atoms absorb or emit only specific energies or…

Learning Objectives By the end of this section, you will be able to: The idea that matter is composed of tiny particles called atoms is at least 25 centuries old. It took until the twentieth century, however, for scientists to invent instruments that permitted them to probe inside an atom and find that it is…

Learning Objectives By the end of this section, you will be able to: Electromagnetic radiation carries a lot of information about the nature of stars and other astronomical objects. To extract this information, however, astronomers must be able to study the amounts of energy we receive at different wavelengths of light in fine detail. Let’s…

Learning Objectives By the end of this section, you will be able to: Objects in the universe send out an enormous range of electromagnetic radiation. Scientists call this range the electromagnetic spectrum, which they have divided into a number of categories. The spectrum is shown in Figure 5.6, with some information about the waves in each…

Learning Objectives By the end of this section, you will be able to: Coded into the light and other kinds of radiation that reach us from objects in the universe is a wide range of information about what those objects are like and how they work. If we can decipher this code and read the…

The nearest star is so far away that the fastest spacecraft humans have built would take almost 100,000 years to get there. Yet we very much want to know what material this neighbor star is composed of and how it differs from our own Sun. How can we learn about the chemical makeup of stars…