The light is first and foremost a form of vital energy for living species on Earth. It beats our daily lives, brings us the energy to live healthy, and more importantly with light we can see … Actually we do not see with our eyes as day and night before our eyes retain the same physiological characteristics.
This is because the light emitted from the sun than the objects or bodies which themselves refer this light that we all seem visible. The sun is different radiation as white light, ultraviolet (which allow us to produce vitamin D) and infrared (responsible for heat). White light is called incoherent because it leaves in all directions and the elements that compose have different characteristics (speed, wavelength …).
This point interested us more than others. Because without light the hologram can be seen, the effect of the play of light is essential. It is therefore important to know the basic functionalities.
The light comes from two components :
– An electromagnetic wave(3)
Electromagnetic waves are not visible to the human eye because its wavelength is less than 380 nm (the limit at which the human eye can discern a wave is between 380nm and 780nm), in the category we find the radio waves, ultraviolet, infrared and X-rays and gamma rays.
– From photon(4)
Photon that cause an interaction with an atom (A photon is a mental projection to understand the interaction between electromagnetic wave and matter. The principle was deciphered by Einstein with the famous equation :
E = mc²
The white light is actually a mixture of several colors (wavelengths) of between 50 nanometers and 650 nanometers. This light is visible on a rainbow, the rainbow occurs when two phenomena are assimilated together, it rains and the sun is visible, the sun crosses the straw that behave like a prism (with light is diffracted) which gives the appearance of colored rainbow. One might venture to say that the rainbow is white light hologram.
To decompose the spectral colors of the light we have to use a prism. The beginnings of this discovery began with Isaac Newton, “Opticks” and Goethe, in “Color Theory”.
3 Source image : http://www.olympusmicro.com/primer/java/wavebasics/index.html
4 Source image : http://www.astrosurf.com/buil/us/stage/session1/make0.htm