The part of the electromagnetic spectrum that has slightly lower energy than visible light, but is not visible to the human eye. Just as there are low-pitched sounds that cannot be heard, there is low [..]

The part of the electromagnetic spectrum that has slightly lower energy than visible light, but is not visible to the human eye. Just as there are low-pitched sounds that cannot be heard, there is low [..]

Infrared radiation (or infrared light) is invisible to the human eye, but can be sensed as 'heat', or thermal radiation. Even cold objects emit infrared radiation. It has a wavelength between 7000 Angstroms (less than a micron) and several hundred microns. (See also Electromagnetic radiation.) Only a small fraction of the infrared light c [..]

Electromagnetic waves longer than those of visible light and shorter than radio waves.

invisible light with wavelengths roughly between 750  nm and 1  mm

Invisible light beyond the 750 nanometers(red end of the visible lights).

The part of the electromagnetic spectrum that has slightly lower energy than visible light, but is not visible to the human eye. Just as there are low-pitched sounds that cannot be heard, there is low-energy light that cannot be seen. Infrared light can be detected as the heat from warm-blooded animals.