The methods used to propagate (transmit) waves through space are based
on the same physical principles today as they were 70 years ago. In this
chapter, we discuss propagation theory on an introductory level, without
going into the technical details that concern the engineer. Understanding
wave propagation requires you to use your imagination to visualize the
associated concepts and how they are used in practical application. To
help you in this process, this chapter includes many illustrations and
step-by-step descriptions that guide you from simple concepts to more
complex ideas. This chapter covers the fundamentals of wave propagation
and the physical factors that affect propagation. Many of the principles
discussed are observable in common, everyday occurrences with which
you are already familiar.
1-1. Learning objectives are included at the beginning of each chapter and
serve as a preview of the information you are expected to learn.
Comprehensive check questions are included at the end of the chapters and
are based on the learning objectives. Upon completing this chapter, you
should be able to do the following:
State what sound waves are and define a propagating medium.
List and define terms as applied to sound waves, such as cycle,
List the three requirements for sound.
Define pitch, intensity, loudness, and quality and their application to
State the acoustical effects that echoes, reverberation, resonance, and
noise have on sound waves.
Define light waves and list their characteristics.
List the various colors of light and define the terms reflection,
refraction, diffusion, and absorption as applied to light waves.
State the difference between sound waves and light waves.
State the electromagnetic wave theory and list the components of the