Longitudinal and Transverse Wave Motion
Visit this page describing the properties of wave motion. Wave motion is a mechanism by which energy is conveyed from one place to another. What form of wave motion needs no material for transmission?

Shh! Don’t Make Waves
Shh! Don't Make Waves describes the physic principles behind sound waves. The speed that sound travels depends on the medium it is passing through. Review the information in this article. What factors affect the speed of sound?

Explore Science
Use this activity at Explore Science to understand more about wave interference patterns. Click the pattern to move it around or use the blue arrows to watch different interference patterns develop. Describe what happens when the standing waves overlap in different orientations.

Zona Land
Visit the Wave Interference page at Zona Land to learn more about this physics principle. Click the Two Source Interference Pattern link to experiment with patterns produced when two circular periodic waves interfere. Click the Explanation of Constructive Interference and Explanation of Destructive Interference links to read more about these principles. What is the difference between constructive and destructive interference?

Kosmoi
Review the Radio Astronomy page at Kosmoi to find out about the history of radio astronomy. Radio astronomy has improved our knowledge of the evolution of stars, the structure of galaxies, and the origin of the universe. What are some of the sources of radio waves?

National Radio Astronomy Observatory (NRAO)
The National Radio Astronomy Observatory is part of the National Science Foundation and operates radio telescopes in West Virginia, New Mexico, and Arizona. These facilities help scientists study all types of astronomical objects in our solar system as well as to the edge of the universe. Learn more about radio astronomy by reading NRAO's frequently asked questions page. What is a radio telescope?