∞ generated and posted on 2016.12.19 ∞

Fundamental, irreducible, and particulate quantity of light.

Light is often described as having a wave-particle duality, with the particle part the photon but also the inherent "vibrations" of photons giving rise the wave as protons travel forward. Despite this "particle" nature, photons when they are not moving in fact lack mass. The wave nature of photons results in their possessing wavelengths which, in turn, are a function of the energy carried by a photon. The different colors that we observe using our eyes are a consequence of different sensitivities of the photoreceptors in ours to different wavelengths of light.

Figure legend: OK, this is not a 'photon' so much as an image of oncoming car lights some dark and seemingly snowy night.

Photons are important to biology most notable because of their capture during photosynthesis and also because the sense of vision is one of photon detection. They also are the means by which the heat energy associated with the Sun is carried to Earth, via photons found in what is known as the infrared portion of the electromagnetic spectrum. The UV spectrum, which can lead to DNA damage and mutation as well as synthesis of vitamin D is also a portion of the electromagenitic spectrum which, energetically consists – in increasing energy order – of radio waves, microwaves, the infrared spectrum, visible light, ultraviolet radiation (UV), X-rays, and gamma rays.