Importance of Light

Serena Cuoghi
Title of Professor of Biology

The importance of light for all living beings and for man in particular is revealed in the simple fact that the entire human organism is prepared to perform correctly during the hours of the day. From the ability of our eyes to capture it to the natural inclination of the brain to direct rest towards the hours of the night, it is glimpsed that light is a regulator of human activity implicit in our own genes. From the strictly physical point of view, light is characterized by its dual nature, since it behaves at the same time as a electromagnetic wave (therefore, energy) and as a structure integrated by small corpuscles called photons (therefore, subject). This condition makes it possible to explain a large part of its unique properties, among which its ability to of being the fastest "object" in a vacuum, allowing a displacement of 300 thousand kilometers per second.

Among living beings, it represents the energy source par excellence, perceived in the capacity of the plants, algae and some microorganisms to convert light energy from the sun into energy chemistry. This process is known as photosynthesis and involves the conversion of inorganic molecules (carbon dioxide, water) into organic molecules, such as glucose. Chlorophyll acts as an intermediary molecule to capture energy from light. On the other hand, even the most primitive animals have receptors capable of recognizing and taking advantage of light. In the more evolved forms of life, increasingly complex eyes are observed; in the particular case of nocturnal animals, the ability to capture light increases significantly to achieve visualization even in conditions of great darkness.

Likewise, human civilization is recognized based on light. The mastery of fire at the beginning of time and the subsequent ability to produce light from of electricity have allowed the expansion of technology and productivity in all cultures.

Capacity of light from its properties

Light is a form of electromagnetic energy that can be captured through the sense of sight, however, this is only a fraction. of what this physical phenomenon represents, since in its complex study much has been discovered about it, the behaviors experiments and the applicability that it possesses both naturally, and the one that, between science and technology, has been used until now.

The particular properties of light have made possible its maximum use in different fields from optical physics, in this sense it can be said that the characteristics that light presents can not only vary, depending on the conditions of its generating source, but can also induce changes in the elements that make up the space where it is located. present.

In order to have a clearer idea about the impacts that light can generate both in its behavior as a wave, as well as in the determinable nature of the particles that compose it, it is ideal to take a look at the following properties: 1) the length of the waves influence in color and this in turn allows the generation of a whole spectrum of colors, of which the human eye can only show a small segment; 2) until now, nothing has exceeded the speed at which light is able to travel through a vacuum, with a constant figure that allows it to be used as a reference unit for various physical and mathematical calculations, mainly for the great distances between the bodies in the Universe and their own dimensions; 3) the intensity that refers to the amount of light energy that reaches a given surface at a given time; 4) polarization, through which the orientation of light waves is indicated, a fact that has been very useful in activities such as photography or fiber optic communication.

From its properties, when light meets a surface, it can be reflected, which means it bounces off the surface, or refracted, deflecting as it passes through the surface, both qualities have great applicability in optics and computer engineering. materials; on the other hand, the phenomenon of diffraction refers to the ability of light to bend around an obstacle or through an opening, a very useful behavior for the scientific research and engineering, who also take full advantage of dispersion, as a phenomenon of separation of light at different wavelengths, allowing the study of spectroscopy that is used to analyze the chemical composition of substances, while absorbance as a calculation that allows determining the amount of light absorbed by a material, and its transformation into another form of energy, such as heat or electricity, a circumstance that can be used for the development of energy technology sustainable.

precursor energy of life

However, all these light conditions were indisputably exploited with billions of years of advantage by each of the other species that have lived. lived on the planet, and it is that the presence of light becomes one of the determining factors that have made possible the generation, evolution and maintenance of life, even of those beings that are currently inhabiting areas with extreme conditions with a partial or even total lack of light from the sun, but that by evolutionarily developed chemical means, are even capable of generating their own light when they need it, through a phenomenon known as bioluminescence.

Photosynthesis itself is not possible without the presence of light and this phenomenon is produced by plants and other photosynthetic organisms, such as phytoplankton. and some bacteria, is capable of incorporating the energy of sunlight into the trophic chain, producing new sources and dynamics of energy for feeding animals. all.

Lights and colors in emotions

Light also has a significant impact on vision and the psychological and physiological well-being of human beings, which is why the studies on how this and its various phenomena have an impact both at an organic level and in the human psyche, with facts ranging from the stimulation and regulation of the circadian cycles that allow the regeneration of organs, systems and tissues, such as the impact that colors and light frequencies have on the eyes and the brain.

In light of the damage

Although it is true that light represents an infinity of benefits, and exposure to the sun's rays allows functions such as the production of vitamin D in the body, which is essential for the health of the bones and the immune system, also the excess of it and its type of origin can end up generating negative effects such as the development of cancer in the skin and the deterioration of the various structures that allow us to see the world around us, in addition to having a significant impact on the quality of sleep, and mental and physical health in general.

References

Aguinaga Dimas, J. L., Reyes Alvarez, E. Y., & Salazar Delgado, B. no. (2020). Fourier series and the phenomenon of light diffraction (Doctoral dissertation).

Belendez, A. (2008). The unification of light, electricity and magnetism: Maxwell's “electromagnetic synthesis”. Brazilian Journal of Physics Education, 30, 2601-1.

Calvillo Cortes, A. b. (2010). Light and emotions: study on the influence of urban lighting on emotions; based on the emotional design. Universitat Politècnica de Catalunya.

De Las Rivas, J. (2000). Light and the photosynthetic apparatus. Fundamentals of Plant Physiology. AZCON BIETO J, 131-153.

Fernández-Peñas, P., & García-López, M. Á. (2003). Solar radiation in the dermatology laboratory: importance of the light source, filters and spectrometry. A model with keratinocyte culture. Actas Dermo-Sifiliográficas, 94(8), 528-534.

Galindo, A. M., Murcia, D. P., & Morales, J. K. (2008). Deductive method for the beginning of the theme: phenomena and nature of light from the phenomenon of diffraction. Gondola, Science Teaching and Learning, 3(1), 114-121.