What is light?

Light is an electromagnetic radiation and we generally refer to what is visible to us. The light is transmitted in the form of waves whose reflection illuminates the surfaces allowing us, in this way, to see the objects and colors around us.


The colors that the human eye can distinguish are located within what is called the visible spectrum of light.

In this sense, the light is manifested by wavelengths, at the end of the longest waves we have the type of radiation like that of the radio waves, and at the end of the shorter waves are gamma rays. Both ends of the spectrum are invisible to human vision.

The ways in which light propagates are defined in what is known as the electromagnetic spectrum. Visible light is between infrared and ultraviolet light.

As a source of light we refer to everything that originates energy, either in visible or invisible terms, such as:
  • the sun produces light in the form of light energy , within the electromagnetic spectrum that lies between visible light and ultraviolet light,
  • the power supplies that generate electricity with efficiency technologies and energy saving as LED lights, and
  • the so-called spiritual sources that grant the faithful spiritual light or divine light.

Light properties
The properties of light are constantly studied especially in physics and in color theory that answers questions like black and white are colors?

The study of the properties of light was only possible thanks to Newton's prism , which subsequently creates the basis for the study of optics. Isaac Newton (1643-1727) exposes his research on the interaction of light with other subjects in his Optical work of 1704.

Some of the most important properties define that light:
  • spreads in a straight line,
  • defined as an incident ray that reaches a surface,
  • defined as reflected beam when bouncing on a reflective surface,
  • It changes direction when it refracts from one surface to another,
  • Let the human eye see the shapes and colors.

See also Color

On the other hand, there are two types of light reflection according to the type of surface on which it is reflected:
  • The specular reflection : happens on smooth surfaces such as mirrors where the rays go in the same direction.
  • The diffuse reflection : occurs on rough surfaces where the rays bounce off in all directions allowing us to see the contours of an object.

Speed ​​of light

The speed of light in a vacuum is unsurpassed in the Universe, the fastest measured speed being almost 300 thousand kilometers per second. It is considered in the scientific community as one of the constants of nature.

The speed of light is considered a constant in nature by definition and a speed of 299,792,458 meters per second is calculated in the vacuum symbolized by the letter c .

The letter c for the speed of light originates in the Latin celeritas which means speed or speed .

The importance of the speed of light lies in the fact that it serves as a limit speed for the universe and in that it describes the property of electromagnetic waves according to the theory of relativity of Albert Einstein published in 1916.

The expression E = mc² of Einstein's theory of relativity expresses the equivalence between mass and energy having c (speed of light) as a constant of proportionality that links matter (m) and energy (E), so So no information can reach an object faster than the speed of light.

A body that is capable of traveling at the speed of light would go around the Earth 7.5 times in a second following the circumference of the equator.

In the field of quantum mechanics , the latest experiments carried out at the Delft University of Technology in the Netherlands in 2015 proved, with 80% of correct correlations, that the influence or transmission of information can be instantaneous and not necessarily linked to The speed of light .

The Portuguese scientist João Magueijo (1967) is the author of the Theory of Variable Speed ​​of Light or (VSL), which stipulates that the speed of light may not be constant as, for example, in the early universe, when the speed of light was much faster.

Post a Comment

0 Comments