What is a “wave”? I don’t think I can give you an entirely satisfactory answer – the concept is intrinsically somewhat vague – but here’s a start: A wave is a disturbance of a continuous medium that propagates with a fixed shape at constant velocity. Immediately I must add qualifiers: in the presence of absorption, the wave will diminish in size as it moves; if the medium is dispersive, different frequencies travel at different speeds; in two or three dimensions, as the wave spreads out, its amplitude will decrease; and of course standing waves don’t propagate at all. But these are refinements; let’s start with the simple case: fixed shape, constant speed, one dimension (Fig. 9.1).
Review the options below to login to check your access.
Log in with your Cambridge Aspire website account to check access.
If you believe you should have access to this content, please contact your institutional librarian or consult our FAQ page for further information about accessing our content.