Radio Wave Errors: Students Mistaking Radio Transverse Electromagnetic Light Waves as Longitudinal Sound Waves

Abstract

Commonly anecdotally noted among physics instructors is
that students often misidentify radio-waves as sound waves, not as part
of the electromagnetic light-energy spectrum. To highlight the
prevalence of this error, a pilot survey, whose results are presented here,
was made of a total of 225 high school physics students from four high
schools in New Jersey in the USA, taken immediately after students had
covered both sound and electromagnetic radiation. Note that although
the study is made in one locality, there is likelihood that the same data
would be obtained in any introductory physics classroom and future
studies are suggested. This survey suggests that a majority of students
appear to still incorrectly conclude that 'radio waves' are sound, even
after instruction otherwise. This is perhaps reinforced by students'
sensory illusion interpretation which might be articulated as: "I hear a
radio, I experience 'radio broadcasts' as sound, so if 'radio signals' are
'radio waves', they are hence sound waves". The survey results were
also sought to see if students who responded that "radio waves are
sound" in this study, more consistently answered other related questions
that used that assumption - that is, once they made that decision, did
they stick with it, even when not consecutively asked the questions in
the survey? Or is it possible that aspects of questioning or syllabi can
mislead students? To help teachers assist students in properly
identifying radio waves some ideas are suggested, particularly directly
challenging students to realize that this is a frequent misunderstanding.