NONPROPAGATING STRING EXCITATIONS

It is shown that certain force distributions applied to a finite porti on of an infinitely long string do not produce any excitation outside the region of the applied force. The existence of such nonpropagating excitations is demonstrated by a simple example, and two general theor ems concerning their nature are proven. Some analogies between nonprop agating string excitations and fields produced by nonradiating sources are noted. (C) 1998 American Association of Physics Teachers.