In this article electromagnetic waves are assumed to be one-dimensional mechanical waves，and delves into the intricate relationships among the constituent elements, wave speed, and energy of both mechanical waves and electromagnetic waves. By establishing connections with the string vibration equation, a compelling revelation emerges. Upon equating the energy and constituent element mass of one wave cycle of a homogeneous string with those of a single wave cycle of electromagnetic waves, it is evident that the wave speed derived from the string vibration equation consistently matches the constant speed of light. From this, a hypothesis takes root: electromagnetic waves manifest as waves resulting from the vibration of a uniform, elongated string-like material. Building on this inference, if the theory holds true, under boundary-free conditions, higher-frequency electromagnetic waves would exhibit larger amplitudes. For electromagnetic waves with a 355 nm wavelength under boundary-free conditions, the amplitude would exceed m, and the average speed of mass points moving between the equilibrium position and the antinode would exceed times the speed of light. When measuring the time difference for vibration traveling from the equilibrium position to the antinode position using equipment with a time-resolution limit of s, no time difference is displayed by the equipment. The measurement result should be instantaneous—thus under such measurement precision and boundary-free conditions, electromagnetic wave energy can instantaneously reach any position within the transverse amplitude range from the vibration equilibrium position. Although air contains numerous molecules that collide with vibrating strings, intermolecular gaps exist, making it possible to detect instantaneous energy arrival phenomena within a certain lateral deviation range from the vibration equilibrium position. In experiments conducted in air using 355 nm pulsed laser light, instantaneous electromagnetic energy arrival was discovered within a 10 cm lateral deviation from the central light spot path, validating the theory.