Light is a form of radiant electromagnetic energy that, due to this condition, can be perceived without any problem by the human eye.. Obviously, since a few centuries ago, different scientists or simply people interested in the study of matter have been dealing with the study of this phenomenon of light, however, since its creation a few years ago, it is optics the discipline that is responsible for the study of the main ways of producing light, its control and applications.
Visibility by our eyes is due to the fact that, like all electromagnetic waves, light is characterized by a phenomenon called wavelength, by which its pulses are separated by a distance that is incredibly small, since it is measured in nanometers. The shorter the wavelength, the greater the energy of that wave. Light visible to the human eye has a wavelength of between 400 and 750 nanometers, approximately, blue light being the shortest. In this range of values, it is possible the stimulation of the cells of the retina that translates that impact of the light in the form of neuronal impulses and, for our brain, in images of what surrounds us.
Likewise, of all the works that have been done throughout history to obtain details, it is known that the light has a finite velocity whose exact value in vacuum for example is 299,792,458 m / s. Now, this figure as long as its deployment is through a vacuum, while, when it must travel through matter, its speed will be lower. This property makes it the fastest phenomenon in the known universe, which is why all existing speeds are calculated as relative to the speed of light, a fact defined by Einstein in his theory of relativity.
One of the The most characteristic phenomena in which light is the protagonist is that of refraction, which is the one that occurs when the light changes its medium, producing a sudden change in the direction of this. This has its explanation because light propagates at different speeds according to the medium through which it has to travel, then, the change in direction will be more important the greater the change in speed, being that light will always prefer to travel long distances by those means that suppose a faster speed. Some of the most common examples that are often used so that we all take into account and visually understand this phenomenon of refraction is the apparent break that can be observed when introducing a pencil in water or the rainbow.
On the other hand, we find that light travels almost always in a straight line; We can see this, for example, when in an environment that has not yet been cleaned, the dust particles are observed straight. Meanwhile, when light meets any object on its way, what are known as shadows will emerge.. But, when at the beginning of the paragraph I told them almost in a straight line, it has to do with the fact that this is not always the case, since when the light passes through a pointed body or a narrow opening, the light beam will bend losing the straight direction that we said before. The latter is known as diffraction phenomenon.
These peculiarities are attributed to the fact of the dual behavior of light. On the one hand, it is undoubtedly a wave, with reflection and refraction phenomena. However, the curvature that the light wave adopts in certain contexts has motivated numerous investigations by which it was deduced that light is made up of particles different from those of matter, which have been called photons. Therefore, although it may seem paradoxical, light is at the same time a corpuscular phenomenon (formed by tangible and defined elements) and an energetic phenomenon. These photons represent the particles captured by the retina of the eyes of animals or chlorophyll molecules of plants that carry out photosynthesis processes. In this way, the simple light that illuminates our daily work is actually a very complex reality that modern physics has not yet managed to fully define.
