In electromagnetic radiation, the oscillating values represent the oscillations of the electric and magnetic fields. Electromagnetic waves consist of mutually perpendicular electric and magnetic fields that oscillate in a synchronized manner and propagate through space.
When we talk about the oscillations of the electric field, it means that the strength and direction of the electric field are changing periodically over time. Similarly, the magnetic field also oscillates in synchronization with the electric field.
These oscillations are not associated with the motion of physical charges, but rather with the changing strength and direction of the fields themselves. In other words, the electric field oscillates between positive and negative values, and the magnetic field oscillates between positive and negative values, as the wave propagates through space.
The oscillations are typically described mathematically using a sinusoidal waveform, such as a sine or cosine function. The frequency of the oscillations corresponds to the frequency of the electromagnetic wave, and the amplitude represents the strength or intensity of the fields.
It's important to note that these oscillations are not spatial displacements of physical objects. Instead, they describe the varying strengths and directions of the electromagnetic fields at different points in space as the wave propagates. The wave itself carries energy and information, and its oscillations represent the alternating pattern of electric and magnetic fields.