We explain what optics is, its history, impact on other sciences and how physical, geometric and modern optics differ.
What is optics?
The optics It is a branch of physics that is dedicated to the study of visible light: its properties and behavior. It also analyzes its eventual applications in human life, such as the construction of instruments to detect or use it.
Light has been defined by optics as a band of electromagnetic emissions whose behavior is similar to that of other invisible (to us) forms of the electromagnetic spectrum, such as ultraviolet or infrared radiation.
This means that its behavior can be described according to wave mechanics (except in very specific contexts in which light acts as a particle) and the approaches of classical electrodynamics of light.
Optics is a very important field of research that provides tools to other sciences, especially astronomy, engineering, photography and medicine (ophthalmology and optometry). We owe it to the existence of mirrors, lenses, telescopes, microscopes, lasers and fiber optic systems.
History of optics
The field of optics has been part of human concerns since ancient times. The first known attempts at lenses date back to ancient Egypt or ancient Mesopotamia, such as the Nirmud lens (700 BC) made in Assyria.
The ancient Greeks were also concerned with understanding the nature of light which they understood based on two perspectives: their reception or vision and their emission, since the ancient Greeks thought that objects emitted copies of themselves through light (called eidola). Philosophers such as Deocritus, Epicurus, Plato and Aristotle studied optics extensively.
Taking over from these scholars were the Islamic alchemists and scientists during the European medieval period, such as Al-Kindi (c. 801-873) and especially Abu Ali-al-Hasan or Alhazen (965-1040), considered the father of optics for his optics book (11th century), where he explores the phenomena of refraction and reflection.
The European Renaissance brought that knowledge to the West, especially thanks to Roberto Grosseteste and Roger Bacon. The first practical glasses were made in Italy around 1286. Since then, the application of optical lenses for different scientific purposes has not ceased.
Thanks to optics, geniuses such as Copernicus, Galileo Galilei and Johannes Kepler were able to carry out their astronomical studies. Later, the first microscopes allowed the discovery of microbial life and the beginning of modern biology and medicine. The entire Scientific Revolution is due, to a large extent, to the contribution of optics.
Physical optics
Physical optics are those that considers light as a wave propagating in space. It is the branch of optics that remains most faithful to the principles and reasoning of physics, making use of prior knowledge such as Maxwell's Equations, to cite an important example.
In that way, is concerned with physical phenomena such as interference, polarization or diffraction. In addition, it proposes predictive models to know how light will behave in certain situations or in certain media, if not numerical simulation systems.
geometric optics
Geometric optics born from the geometric application of phenomenological laws around refraction and reflection by Willebrord Snel van Royen (1580-1626), the Dutch scientist known as Snell.
To do this, this branch of optics starts from the existence of a light ray, whose behavior is described by the rules of geometry to find formulas corresponding to lenses, mirrors and diopters. In that way it is possible to study phenomena such as rainbows, the propagation of light and prisms. All this using the language of mathematics.
Modern optics
The contemporary branch of optics arises with quantum physics and the new fields of knowledge that the latter made possible, as well as its eventual applications through engineering. Thus, modern optics encompasses a huge variety of new fields of research regarding light and its applications, including:
- The mechanisms of laser (light amplification by simulated emission of radiation).
- The photoelectric cells LED lights and metamaterials.
- The optoelectronics hand in hand with computing, and digital image processing.
- The lighting engineering with applications in photography, film and other fields.
- Quantum optics and physical study of the photon as a light particle and light wave at the same time.
- The atmospheric optics and the understanding of atmospheric light processes.
Continue with: Color theory
References
- “Optics” on Wikipedia.
- “What is optics” in ILCE Digital Library.
- “Optics” in Enciclopedia.us.
- “Geometric optics” at Khan Academy.
- “Optics” in The Encylopaedia Britannica.
