The difference between the wavelengths of light that we can see and those that we can't see lies in the range of electromagnetic radiation known as the visible spectrum. The visible spectrum refers to the specific range of wavelengths of electromagnetic radiation that the human eye is sensitive to and perceives as various colors.
The visible spectrum spans approximately from 400 nanometers (nm) to 700 nm in terms of wavelength. Within this range, different wavelengths are associated with different colors. For instance, light with a wavelength around 400 nm is perceived as violet, while light with a wavelength around 700 nm is perceived as red. In between these extremes, we perceive light with wavelengths corresponding to blue, green, yellow, and orange.
Outside of the visible spectrum, there are wavelengths of electromagnetic radiation that we cannot see with the naked eye. These wavelengths include both longer and shorter wavelengths compared to the visible spectrum. Longer wavelengths, such as infrared (IR) and radio waves, are associated with lower energy levels. Infrared radiation has wavelengths longer than 700 nm and is often used in applications such as thermal imaging or remote controls.
On the other hand, shorter wavelengths, such as ultraviolet (UV), X-rays, and gamma rays, are associated with higher energy levels. Ultraviolet radiation has wavelengths shorter than 400 nm and is responsible for effects like sunburn and the fluorescence of certain materials. X-rays and gamma rays have even shorter wavelengths and are commonly used in medical imaging and radiation therapy.
While we cannot see these wavelengths directly, specialized devices and instruments are designed to detect and measure them, such as infrared cameras, UV detectors, X-ray machines, and gamma-ray detectors.
In summary, the difference between the wavelengths of light that we can see and those we cannot see lies in the range of the visible spectrum. The visible spectrum encompasses wavelengths from approximately 400 nm to 700 nm, while wavelengths outside this range, both longer and shorter, fall into the infrared, ultraviolet, X-ray, and gamma-ray regions, which we cannot perceive with our naked eye.