Everyone is familiar with heat because of our sense of touch.
Heat is a form of light invisible to our eyes, but detectable with our skin.
Glowing vs. Reflecting The light that we see with our eyes originates from a glowing source, a light bulb or the sun, for example. But that light also can reflect off of surfaces and reach our eyes. This allows us to see things that don't emit their own light. Infrared light also is emitted and reflected. Unlike visible light though, infrared light is emitted by any object that has a temperature above absolute zero.