How do we see invisible light?
Engineers can design special types of detectors that are sensitive to different types of radiation.
Observing the Universe at a variety of wavelengths requires special telescopes and instruments. To see infrared light, instruments need to be cooled, otherwise they emit too much infrared radiation themselves. Ground-based telescopes can observe in the visible, near- and mid-infrared and radio. Far-infrared wavelengths can only be studied by high-flying aircraft, balloon-borne instruments and space telescopes. High energy radiation like ultraviolet and X-rays can only be observed from space.
Dogs can hear high-pitched sounds that your ears don’t notice – “unhearable” sounds. In the same way, there’s light that our eyes can’t see: “invisible” light. To see it, you need special cameras.