Part 3, Working with Waves Summary and Analysis

Whereas Part 2 described how machines move and alter molecules, Part 3 covers machines that use the energy of waves "to amplify and extend our eyes and ears." (p176) The two types of waves discussed are sound waves and electromagnetic waves. Waves differ from molecules in that molecules make up matter whereas waves pass through it. Electromagnetic waves are often referred to as rays. Whereas sound waves pass a vibration through molecules, electromagnetic waves vibrate electric and magnetic fields which can exist outside of matter. The distance between each peak of energy is the wavelength. How quickly the waves move past each peak is called their frequency. All waves and rays span a range of wavelengths and frequencies which effect how we perceive them. The frequency of sound waves creates a physical vibration which humans experience both...