Infrared (IR) and ultraviolet (UV) wavelengths are both forms of electromagnetic radiation, but they exist at opposite ends of the electromagnetic spectrum. Here are the key differences between them:
Wavelength Range: Infrared radiation has longer wavelengths than visible light, ranging from approximately 700 nanometers (nm) to 1 millimeter (mm). Ultraviolet radiation, on the other hand, has shorter wavelengths than visible light, ranging from about 10 nm to 400 nm.
Human Perception: The human eye is sensitive to a small range of wavelengths known as the visible spectrum, which lies between approximately 400 nm (violet) and 700 nm (red). Infrared light falls beyond the red end of the spectrum, while ultraviolet light falls beyond the violet end. Therefore, we cannot see either of them with our naked eyes.
Interaction with Matter: Infrared and ultraviolet radiation interact with matter in different ways. Infrared radiation is associated with heat and is emitted by objects due to their temperature. It can penetrate some materials and is commonly used in thermal imaging technology. Ultraviolet radiation, on the other hand, has higher energy and can cause chemical reactions and damage biological tissues, such as sunburns and skin cancer.
Applications: Infrared and ultraviolet radiation have various practical applications. Infrared is used in night vision devices, remote controls, thermal imaging cameras, and even for studying celestial objects that emit infrared light, such as stars and galaxies. Ultraviolet radiation has applications in medicine (e.g., UV light therapy), sterilization processes, fluorescence analysis, and certain types of printing.
While we cannot see infrared light directly, we can detect it indirectly through specialized cameras and sensors that convert infrared radiation into visible images or data.