Other animals, like snakes, are able to see infrared light. It covers all energies of light, extending from low-energy radio waves, to microwaves, to infrared, to optical light, to. But the electromagnetic spectrum encompasses more than just optical light.

Optical radiation, which includes adjacent infrared and ultraviolet portions of the spectrum, covers a frequency range of approximately 151500 THz. Spiders and many insects can see a type of light called ultraviolet that most humans cannot see. Each colour within the visible light spectrum corresponds to a narrow band of wavelength and frequency The different colours of waves correspond to different. The resultant rainbow is really a continuous spectrum that shows us the different energies of light (from red to blue) present in visible light. Visible light occupies a portion of the electromagnetic spectrum between frequencies of approximately 400 terahertz (THz) to 750 THz, where 1 THz is 10 12 oscillations per second. However, some animals see colors we cannot. Their view of the world is made of pastel colors. The reality, which Planck discovered, is that energy is not continuous but quantized-meaning that it can only be transferred in individual “packets” (or particles) of the size h ν h u h ν h, u. Your pet dog and cat sees fewer and weaker colors. This was a shocking discovery, because it challenged the idea that energy was continuous, and could be transferred in any amount. Visible radiation is assumed to contain electromagnetic waves in the spectrum in a very narrow range, from 380 to 780 nm. 6 2 6 × 1 0 − 3 4 J ⋅ s 6, point, 626, times, 10, start superscript, minus, 34, end superscript, start text, space, J, end text, dot, start text, s, end text, and ν u ν u is the frequency of the light absorbed or emitted. Planck observed that matter actually absorbed or emitted energy only in whole-number multiples of the value h ν h u h ν h, u, where h h h h is Planck’s constant, 6.626 × 1 0 − 34 J ⋅ s 6.626 imes10^ 6. Planck found that the electromagnetic radiation emitted by blackbodies could not be explained by classical physics, which postulated that matter could absorb or emit any quantity of electromagnetic radiation.

Visible light spectrum