Here's why:
* Electromagnetic waves are disturbances in the electric and magnetic fields. These fields are intertwined and propagate together at a speed determined by the permittivity and permeability of the medium.
* In a vacuum, there is no matter to interact with the electromagnetic waves. This means the permittivity and permeability are constant, resulting in a fixed speed of propagation for all electromagnetic waves.
Different types of electromagnetic radiation (such as radio waves, visible light, X-rays) have different frequencies and wavelengths. However, their speed in a vacuum remains the same. The only difference is the energy carried by each wave, which is directly proportional to its frequency.
Important Note: While the speed of light is constant in a vacuum, it can change when passing through different materials (like air, water, glass). This change in speed is what causes phenomena like refraction.
