Yes, electromagnetic waves can generally travel through walls, although the extent to which they can penetrate depends on the type of wall and the characteristics of the electromagnetic waves.
Electromagnetic waves encompass a wide range of frequencies, including radio waves, microwaves, infrared radiation, visible light, ultraviolet radiation, X-rays, and gamma rays. These waves are characterized by their ability to propagate through space without requiring a medium.
When it comes to walls, their ability to allow electromagnetic waves to pass through depends on various factors such as the composition, thickness, and density of the material. For example, radio waves and microwaves have relatively long wavelengths and can often pass through common building materials like wood, drywall, glass, and certain types of plastic with minimal attenuation. This is why Wi-Fi signals and cellular signals can pass through walls and provide coverage indoors.
However, as the frequency of electromagnetic waves increases, their ability to penetrate solid objects diminishes. For instance, higher-frequency waves like ultraviolet, X-rays, and gamma rays have shorter wavelengths and can be easily absorbed or scattered by most materials. This is why X-rays and gamma rays are used in medical imaging but require special shielding to protect against their harmful effects.
So, while electromagnetic waves can generally travel through walls, the degree to which they can penetrate depends on the specific frequencies involved and the properties of the materials constituting the walls.