What is non visible light?

Answer 1

Plenty. Electromagnetic radiation can occur at all wavelengths imaginable but our eyes can only sense a very narrow band of these (called the visible spectrum, called "light"). Radio waves for example are at frequencies we cannot see, though they can be detected by other methods (radio receivers). X rays are another example, actually damaging if a person is exposed to them for a significant time.

Answer 2

The instant I saw this question, and realized the agony and distress of Emdrgreg
and the others waiting on pins and needles to see how it comes out, I knew that
it was my duty to attempt to resolve the tension. I switched on the feature that
my ISP provides at a nominal additional monthly charge, called

, and I
cast about the W3 for some words that might help settle the dilemma. As search
parameter, I entered the phrase "electromagnetic spectrum", and at internet speed,
there, at the top of the results, was the sentence I needed, labeled "Definition" !
It said:
The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation.
As if that in itself were not enough, it then went on to add:
The electromagnetic spectrum extends from below the low frequencies used for modern radio communication to gamma radiation at the short-wavelength (high-frequency) end, thereby covering wavelengths from thousands of kilometers down to a fraction of the size of an atom. The limit for long wavelengths is the size of the universe itself, while it is thought that the short wavelength limit is in the vicinity of the Planck length, although in principle the spectrum is infinite and continuous.
Comes now the curious, and asks what type of electromagnetic radiation is not
found on the electromagnetic spectrum. Where angels may fear to tread, we,
however, rush in, to proclaim that the spectrum BY DEFINITION includes "all
possible frequencies of electromagnetic radiation", and so it is therefore BY
DEFINITION that no type of electromagnetic radiation can exist apart from the
spectrum.

Having totally convinced myself, I now rest my case.

Answer 3

Radio waves, Microwaves, Infrared light, Ultraviolet light, X-rays, Gamma Rays are all examples of non visible light.