The ability of electromagnetic waves to pass through walls or objects depends on various factors, including the frequency of the wave and the nature of the material it encounters. While it is true that gamma waves have the highest frequency and can penetrate some materials, and radio waves have lower frequencies and can pass through walls, visible light behaves differently due to its specific properties.
When visible light interacts with matter, it undergoes a process called absorption. The atoms and molecules in most common materials, such as walls, have certain energy levels or electron configurations. Visible light consists of photons with energies corresponding to specific colors or wavelengths. When these photons interact with the atoms or molecules in the material, the energy of the photons can be absorbed by the electrons, causing them to move to higher energy levels or become excited.
Now, the key point is that the energy levels in atoms and molecules are quantized, meaning they can only exist at certain discrete levels. The energy levels in solids, like those in walls, are closely spaced compared to the energy of visible light photons. This means that visible light photons often have energies that are too high to be absorbed by the atoms or molecules in the material. Instead, they interact with the material's electrons only at the surface, causing them to vibrate or scatter, which we perceive as reflection or absorption.
In simpler terms, visible light cannot pass through walls easily because the atoms and molecules in the wall materials do not have energy levels that match the energy of visible light photons. As a result, visible light is either reflected or absorbed by the wall, preventing it from transmitting through.
In contrast, radio waves have much lower energies and longer wavelengths compared to visible light. These waves are more likely to interact with electrons in the material by causing them to oscillate at the same frequency as the radio waves. This resonance effect allows radio waves to pass through certain materials, including walls, more easily.
It's worth noting that there are exceptions, such as certain types of glass that can transmit visible light due to their specific atomic or molecular structure. Additionally, materials like water and air are transparent to visible light, allowing it to pass through with minimal interaction.