Within the electromagnetic spectrum there is a part, called the visible spectrum, perceived by the human eye.
Visible spectrum is the name given to the area of the electromagnetic spectrum that the human eye can perceive. In general, human vision captures light (as defined as a class of electromagnetic radiation that does not go unnoticed by our visual sense) in a wavelength range that oscillates between 380 and 750 nanometers (nm). There are individuals, however, with the ability to visually react to a wavelength that can start at 310 nm and extend to just over 1000 nm.
According to experts on this topic, among the wide variety of colors that exist, yellow turns out to be the color that, for the human eye, stands out the most.
Concepts linked to the visible spectrum
There are several concepts linked to the visible spectrum . The meaning, meaning or application of this notion cannot be fully understood by ignoring, for example, the definition of electromagnetic radiation .
It is an expression that encompasses a variety of versatile electromagnetic fields made up of both magnetic and electric fields that oscillate and move throughout space, delivering energy from one point to another. Explained in another way, electromagnetic radiation is made up of electromagnetic waves that have the peculiarity of propagating, in a vacuum, at the speed of light and contains modalities that find photons as carrier particles, which are responsible for the transport of energy. .
Within electromagnetic radiation , among others, infrared radiation appears (which has a longer wavelength than visible light although smaller than that associated with electromagnetic waves called microwaves. Ultraviolet radiation , framed in the components of The sun's rays are also electromagnetic radiation : in this case, it is very difficult for human beings to observe these rays.
It is enriching, at the same time, to learn (or keep in mind) that, when referring to a wavelength , the focus is being placed on the distance that a periodic disturbance covers when, in a cycle, it advances through a certain medium. When evaluated in an electromagnetic wave, it is equivalent to the separation observed between two maximum marks of the electric field.
With an optical telescope it is possible to capture and focus on the visible portion of the electromagnetic spectrum, resulting in a magnified image.
Properties and phenomena associated with light
The properties and phenomena associated with light allow us to know how it behaves, manifests itself, and the part that the human eye is able to detect in the face of electromagnetic radiation can vary.
Every time a light wave changes or passes from a certain medium to another, a phenomenon known as refraction arises, which implies a change in speed and direction. It is usual for it to originate, to mention another possibility, a reflection of light (a phenomenon that if it occurs on a polished and smooth surface is called specular or is called diffuse if it occurs on a rough area).
If a transparent space (such as air) is crossed by rays of white light that are refracted, then refractive dispersion occurs. When light in the sky passes through water drops and disperses, breaking down into multiple chromatic stripes, the always picturesque rainbow becomes visible.
In the face of opaque elements and transparent objects, an absorption process occurs that involves electromagnetic radiation . If it occurs within the parameters of visible light, it is defined as optical absorption . There may be, to describe another case, a transmission of light , which may be selective, diffuse or direct: it is the ability to pass through a material, space or medium without altering the frequency of the radiations involved.
By delving into the information in this regard, the notions of interference (produced by a reinforcement and superposition of light waves), diffraction (a phenomenon similar to that of interference that accounts for a deflection of waves around an opening or the corners of a a brake or obstacle) and electromagnetic polarization (covering the classifications of polarized or non-polarized light).
When it rains and the sun is present, the light is divided and a beautiful rainbow emerges.
Colors present in the visible spectrum
The colors present in the visible spectrum are numerous. In the rainbow are those that are generated by visible light involving a single wavelength . Although pink and turquoise exist, for example, red, orange , yellow, green, blue , indigo and violet shine there.
The refraction of light by ice particles that are in suspension also results in a spectrum of colors that surrounds both the sun and the moon . This optical effect is specified as a halo . Another interesting case is that of the halo that frames the upper area of the immense shadow that a certain observer makes with his figure. The visual spectacle that each twilight offers, a panorama driven by the illumination, by the sun, of the highest layers in the atmosphere, is not to be left in the background either.
On the other hand, it is worth noting in relation to colors that there are people whose vision has a defect called color blindness . As a consequence of this issue, which is also described as "color blindness " , those affected tend to confuse the chromatic tones they perceive. The modality called anomalous trichromatism is diagnosed when someone has, like most people, three kinds of pigments although there are alterations in one (or more). Thus, it requires intense stimuli to capture non-functional color.
And if there was space to display data associated with color and light, it is important to balance the balance by mentioning the counterpart: darkness . It is interesting to investigate how the human eye manages to adapt when there is no light or very little light. In this regard, it should be noted that in the retina there are two varieties of photoreceptor cells (with sensitivity to light), called cones and rods (this last variety comes into play in circumstances of decreased light and is key to adaptation to darkness ). .