A photon can be defined as a particle or unit that represents a quantum of electromagnetic radiation for example light. It usually contains energy that is proportional to the radiation frequency. A photon is always in motion with a constant speed of light which is approximately 2.998* 108 m/s whenever there is no form of resistance.
Photons are usually formed in a number of ways, for instance, we can get a photon via the progression of an electron (in an atom) discharging energy which is reached when the particular electron moves to a somewhat lesser orbit around a nucleus. Another way in which a photon could be created is through an acceleration of a given charge (Anato, Moskalenko and Snoke 1). This paper gives an in depth discussion in regard to photons including their origin, their lifecycle, their characteristics as well as their uses.
Origin of photons
The origin of photons can be traced back in the early twentieth century. Lewis Gilbert is associated with photons as he was responsible for bringing out the various concepts of photons in 1926 although the general concept of light had been there for a long time. There had been a belief that light is usually made up of some form of energy even in the ancient times which can be seen in the book of Optics which was published long time ago.
This was true but people did not have the understanding of the photons concept and the fact that they were the ones responsible for the production of energy. During the seventeenth and the eighteenth centuries, people had gained a lot of interest on the aspect of light and a variety of theories were developed in order to understand the key factors underlying it for instance the wavelength and refraction characteristics associated with other particles like the protons.
It was in the beginning of the twentieth century that the discovery of photons came about raising a lot of concern among people. Various studies have been carried out since then in regard to photons leading to many discoveries with the most recent one being that of the laser which have been proved to be very effective in various fields and procedures like X-rays (Bortz 28).
Lifecycle of the photon
Just like a living organism, a photon undergoes t some processes during its entire lifetime (formation, living and death) and the processes can be termed as the lifecycle. A photon has a relatively long life span and could be even infinite unless the light energy in it is consumed, for example, when a photon strikes an object that is likely to absorb it.
The determination of the lifecycle of a photon is an aspect that has proved to be very difficult unlike that of other particles like atoms, ions and electrons. This is due to the fact that in most cases, photons tend to be destroyed once they are detected due to the risks linked with them.
According to the Centre National De La Recherche Scientifique (par 2), the determination of the life cycle has been made possible through a technique where photons are trapped in a superconducting cavity for study. This way, it was a bit easier to study in real time the birth, the life as well as the death of a single photon whose result could be taken as a representative whole.
Anato, Moskalenko and Snoke (3) assert that the emission of a photon could be as a result of excitons which usually have a finite probability for an excited electron to reunite with the whole hence the emission of a photon.
The life cycle for an exciton could be described as follows; there is usually an exciton which is formed as a result of absorption of a photon, the exciton then passes through a solid whereby scattering process is experienced and finally the exciton recombines to emit a photon which usually take place far from the creation point, at some area in the solid.
The lifetime of the exciton is not constant but rather dependent on some factors, for instance, the proportions of the recombination processes and the experimental conditions among other factors. According to the above factors it is argued that the lifetime can range from picoseconds to milliseconds or even longer. All in all much have not been discovered in regard to the life cycle of photons although there is still hope that with time a definite conclusion will be reached.
Characteristics of photon
Photons have a wide range of characteristics and the following are just some of them according to the photon theory of light. According to Zimmerman (2), photons have no mass and resting energy an aspect that sounds not to be realistic but it is proven to be true. Photons however have momentum and energy at the antinodes which is responsible for taking on mass from energy expansion.
This is unlike other particles (like neutrons) that always have a small amount of accumulation under all circumstances. They also move at the speed of light which is 2.998* 108 m/s. Another unique characteristic of photons is that they can either be destroyed or formed when either radiation is absorbed or else emitted.
Photons are also known to have various particle related interactions with electrons and other particles. They do not contain any electric charge whereas all other related particles have an electric charge. For example, neutrons are neutral, protons are positive and electrons are negative. They are generally the smallest measure of light and are able to exist in all possible states concurrently.
Another characteristic unique to photons is that once they are polarized, it becomes very difficult to measure them precisely and it would call for the use of a filter, which is exactly equivalent to that produced by their current spin. They are also emitted through a variety of natural processes and do not decay instinctively in empty space. Apart from the above characteristics, photons posses a distinctive wavelength and a specific state of polarization which is absent in other particles (Clark par. 4)
Uses of photon
Photons have become very essential tools in regard to technology today. They have for instance found their application in various technological devices that either create or produce light as a mechanism of their usability for instance camera flash or even flashlight. This is because the photons are created and manipulated to provide the energy needed for these devices to function.
It is the mechanism and working of photons that has enabled individuals through the use of technology to capture and create light energy in a number of productive ways necessary for various developmental processes (Akkermans and Montambaux 12). Photons have found various applications in the different fields of life like X-rays in medicine, construction sector, weaponry and even electronics.
This has been made possible due to the use of the photons to produce lasers which have various uses in different fields. Despite the benefits associated with photons, there are also some risk factors that come along with handling photons and so people should be more careful on this to avoid injuries. This is so because some photons could be dangerous due to the amount of energy they possess which is dependent on their patterns as well as their wavelength (Orkwell 4).
The concept of photons is not very new although most discoveries have only been made recently. All in all, it has helped a great deal through its various applications especially in medicine and electronics. Photons have been able to stand out distinctively among other particles like the protons, electrons and neutrons due to the unique characteristics they posses.
We can also state that photons in the form of energy are usually infinitely small just as it is the case, infinitely large. Matter as finite energy is also considered as an intermediary as well as part of infinite energy. The future of photons is bright as there are still other discoveries on the way with an aim of bringing even more improvements in various sectors of the economy.
Akkermans, Eric and Montambaux, Gilles. Mesoscopic physics of electrons and photons. Cambridge: Cambridge University Press, 2007
Anato Sviatoslav, Moskalenko Evich and Snoke D.W. Bose-Einstein Condensation of Excitons and Biexcitons: and Coherent Nonlinear Optics with Excitons. United Kingdom: Cambridge University Press, 2000.
Bortz, Alfred .The Photon. New York: The Rosen Publishing Group, 2004
Centre National De La Recherche Scientifique. “Life And Death Of A Photon ‘Filmed’ For The First Time.” Science Daily, 2 Apr. 2007. April 14, 2011.
Clark, Josh. “How Quantum Cryptology Works”. Howstuffworks. 2011. April 14, 2011.
Orkwell, Mark. “About Photons”. Ehow. 2011. April 14, 2011.
Zimmerman, Jones Andrew. “What is a Photon?” About.com. 2011. April 14, 2011.