From Latin lux, the light is he physical agent which allows objects to be visible. The term is also used to refer to the clarity that radiate the bodies, to electric current and the utensil that serves to illuminate.

For instance: “This room needs more light, I don’t see anything”, “Today the electricity bill arrived: we will have to pay double what we paid last month”, “Please bring a light and illuminate that corner”.

Light is a radiant electromagnetic energy that can be perceived by the sense of sight. This is the range of radiation of the electromagnetic spectrum. Light has finite speed and travels in a straight line.

This property of light has been proven both experimentally and theoretically. The first time the speed of light was successfully measured was in the year 1676, and it was done by a Danish astronomer named Ole roemer. From that moment, the measurement it has become more and more accurate thanks to the number of experiments that have been carried out throughout history.

Currently, the exact value that is accepted is 299 792 458 meters per second, as long as the light is in a vacuum. This is because if it must pass through matter, its speed decreases according to the dielectric properties. In this aspect is the refractive index, the relationship between the two speeds.

In more precise terms, it defines refraction as the important variation that the direction of light undergoes when it passes from one medium to another. There is a direct relationship between increasing speed and changing direction; This happens because light can travel greater distances if the medium allows it to travel faster. The so-called snell’s law uses the refractive indices to relate the variation of angle and velocity.

As mentioned above, the spread of light occurs in a straight line, and this is one of its easiest properties to notice. For example, in an environment where there is a lot of dust or where the atmosphere is saturated we can notice it without problem. The geometric optics, which belongs to the field of physics, relies on this to predict where the light is along its path, taking time into account.

Another of the best known properties of light is the reflection. In a perfect case, when it hits a body, its matter retains its energy for a few moments and then emits it again, this time in an infinite number of directions. The most common example in which we can appreciate this effect is the mirror.

Another use of the notion of light is linked to the clarity or the clarification of the intelligence: “My son is a light, he learned to read when he was three years old”, “I have already read dozens of books on the subject, but I still have not enlightened”.

A light can also be a person or thing able to guide and illustrate: “Jesus Christ is the light on my path”, “The captain has been the light of the team with his impetus and effort on the field of play”.

Light is, on the other hand, a female name. In Argentina Y Uruguay, the bad light is he fire fatuous that decomposing bones generate and that, according to local superstitions, are the product of souls in pain of those dead without burial.

The phrase “see the light”Finally, it is linked to birth or death: “When the train was coming towards me, I saw the light”.