The radiant electromagnetic energy that can be perceived with sight is called light.
From the Latin lux , light is the physical agent that allows objects to be visible . The term is also used to refer to the clarity that bodies radiate, the electric current and the utensil that serves to illuminate.
For example: "In this room we need 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 room". corner» .
A radiant electromagnetic energy
Light is a radiant electromagnetic energy that can be perceived by the sense of sight. This is the radiation range 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 1676, and it was done by a Danish astronomer named Ole Roemer . Since that time, the measurement has become increasingly more precise thanks to the number of experiments that have been carried out throughout history.
Currently, the exact accepted value is 299,792,458 meters per second , as long as 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 we find the refractive index , the relationship between both speeds .
A light is something that allows you to illuminate.
Refraction and reflection of light
In more precise terms, refraction is defined as the significant 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 refractive indices to relate the variation of angle and speed.
As mentioned above, the propagation of light takes place 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 a problem. 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 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.
Clarity and illustration
Another use of the notion of light is linked to the clarity or clarification of intelligence : "My son is a light, he learned to read at the age of three" , "I have already read dozens of books on the subject, but I am still not enlightened." » .
A light can also be a person or thing capable of guiding and illustrating : "Jesus Christ is the light on my path" , "The captain has been the light of the team with his drive and effort on the field of play" .
Other uses of the term light
Luz is, on the other hand, a feminine name . In Argentina and Uruguay , the bad light is the will-o'-the- wisp generated by decomposing bones and which, according to local superstitions, are the product of lost souls of those who died without burial.
The phrase "see the light," finally, is linked to birth or death: "When the train was coming towards me, I saw the light."