The electromagnetic spectrum

In short: The electromagnetic spectrum encompasses all types of electromagnetic radiation, from long-wavelength radio waves to short-wavelength gamma rays. Visible light is just a tiny slice of this vast range.

In more detail: The shorter a radiation’s wavelength, the higher its frequency and the more energy it carries, since energy and frequency are directly proportional.

In detail

• Radio waves: The longest-wavelength radiation is used for broadcasting, WiFi, and mobile networks, and is energetically harmless.
• Microwaves: Shorter than radio waves, they’re used for radar, satellite communication, and heating food (mikrowelle-funktionsweise).
• Infrared: Heat radiation emitted by every warm body, which thermal imaging cameras can make visible.
• Visible light: The tiny range the human eye can perceive, spanning from red through green to violet (licht-und-farben).
• Ultraviolet: Higher in energy than visible light, it can cause sunburn and is sometimes used for disinfection.
• X-rays: Pass through soft tissue but are absorbed by bone, making them useful for medical imaging.
• Gamma rays: The highest-energy, shortest-wavelength radiation arises from radioactive decay and cosmic events and is dangerous to living tissue without shielding.