Cycle of Photon Issues - Essay Example

? Cycle of Photon April 08, Table of Contents Table of Contents 2 Introduction 3 Transition in the nucleus 3 Energy levels 4 Factors affecting life cycle of photons 5 Disappearance of a Photon 6 Conclusion 6 References 7 Pradhan, Trilochan. The Photon. NY: Nova, 2001, Print. 7 Introduction A photon is a particle, quantum of light and a form electromagnetic radiation that carries electromagnetic force. Effects of this force can be seen microscopically and macroscopically since photon has no absolute mass and hence allows interactions at long distances. A photon exudes particle-wave duality, hence has both characteristics of both a particle and a wave. It is of negligible mass and does not have electric charge. It has double states of polarization and can be described by three arguments. These arguments are wave vector components, wavelength and direction in which it is propagated. A photon moves with the speed of light in empty space and its energy is affected by momentum and vector. A photon is among some of the rarest particles that are identical to their antiparticles, in this case, antiphoton. Photon is a generalised term used to explain the electromagnetic spectrum in the range of infrared (IR) radiation to visible light. Transition in the nucleus A photon is one particle that is able to transition in the nucleus of an atom. Though motion is limited in the nucleus, a photon is able to change from one position to another. It is at the nucleus that the energy of an atom is found. However, it is essential to note here that the form of the photon is not changed even though its speed is very high owing to the high level of energy in the nucleus. It moves along with angular momentum that is not dependent on its frequency. The component measured along its direction of motion, herein referred to as helicity, and must be an integer of the planks constant, denoted as h. Circular polarization states of the photon are derived from the two helicities described above, either positive or negative of planks constant. Motion of a photon gives rise to energy being produced and hence law of conservation of momentum must come into play. Conservation of momentum with reference to a photon is also referred to as transitional invariance and requires that more than two photons are created having null momentum. A large sized photon has effects on the nucleus of an atom. Though said to be massless, its effects cannot be overlooked. A photon could alter Coulombs law and there would be extra degrees of freedom for electromagnetic fields. Energy levels An atom has a varied number of energy levels also referred to as energy states. In each of these energy levels, electrons oscillate with vibrations and thus produce energy. The number of electrons in each energy level increases as the distance from the nucleus increases. The greater the distance, the higher the energy emitted. A photon is emitted when an electron happens to move from a higher energy level to a lower energy level. The wavelength of the photon is the same as the distance between the two energy levels. This photon emitted has energy and this directly proportional to frequency and Planks constant but inversely proportional to its wavelength. The energy emitted by a photon is not dependent much on its mass since its mass is almost negligible though it is known that all matter has mass and occupies space. However, it is imperative to note that photons exhibit the same behaviour regardless of the energy level they are emitted by the transiting electrons. They travel at the same velocity even if moving from high energy level to lower energy level and the velocity can vary in over ten orders of magnitude from the lowest energies of radio waves to the powerful waves of gamma radiation. Photons are usually depicted as packets that carry energy with them though the energy in the packets is discrete. If the photons are travelling as a beam, intensity of such a beam depends on the number of photons per second. Light is also described as waves, though distance between those waves and wavelength are inversely proportional to energy. Low energy radio waves have wavelengths in the range of meters while high energy x-rays could even have wavelength of a millionth or less than that. Light could be described as a photon or electromagnetic wave viewed as vibrating magnetic and electric fields moving linearly at the speed of light. It is important to put to note that sound waves have no association with photons since sound waves do not form part of electromagnetic spectrum. This is due to the fact that sound, which refers to vibration of air particles, does not travel in vacuum. A notable characteristic in both sound and light waves is that both exhibit wave characteristics though mechanism is different. Factors affecting life cycle of photons The life cycle of a photon is dependent on several factors and none these should be assumed. It is of importance to understand that a photon’s life is not terminated the physical way. This is done via wave’s disruption which in turn leads to destruction. Among the factors that affect the life cycle of a photon is wavelength, velocity, energy dissipated by electrons at the various energy levels of an atom just to mention but a few. Wavelength can be viewed in another way as distance travelled by a particle. A photon that has exhibited a long wavelength is liable to have a short life span since much of its energy would be dissipated during the period of travel. If an electron moves from a lower energy level and moves to a much higher energy level, a photon with high energy is produced. An electron moving from a high energy level to a lower energy level is the one which has high units of energy. A photon’s lifestyle has several factors determining it. The speed of the electron moving from one energy level to another has much effect on a photon’s life cycle. If the speed is really high, it would produce a photon that would again have a lot of effect though the life cycle of such could be short lived. Charge on the electron moving across energy levels of an atom is always negative and hence charge has no effect. Distance which this electron moves is of great significance to a photon’s life. Disappearance of a Photon In physics, matter made can be destroyed. With this notion in mind, it is necessary to understand that a photon too can be destroyed. Its life has an end and though not as the physical mind could think. There is no designated weapon to terminate a photon’s life. In essence, a photon is not destroyed but disappears. Photons are created via electrons motion across energy levels. The process of interaction of electrons and photons is what brings it to life and destruction is via the same mode. Electrons have mass and energy and do not disappear and they change energy. Photons on the other hand do not have mass or energy but they appear and disappear. An electron travelling through the energy levels of an atom loses energy and thereby a photon is created. The photon created is now free to travel in space. It is worth noting that even after an electron has lost energy; it is not eliminated from space but remains there. A photon moving in space encounters electrons and hereby disappears. This is thus the disappearance of a photon. Conclusion A photon is at the heart of understanding quantum mechanics. During the interaction of a photon and an electron in space, a photon gets to transfer all the energy it had gained from an electron thereby getting destroyed. After losing its energy to give rise to a photon, an electron moves to a lower energy level. There is no intermediate state between a photon and an electron. In quantum mechanics equations, one side has both electron and a photon while the other side has an electron alone. References Becker, Wolfgang. Advanced Time-correlated single photon counting techniques. Basel: Birkhauser, 2005, Print. Janesick James. Photon Transfer. Washington: SPIE, 2007, Print. Lee Hsien-che. Introduction to color imaging science. Cambridge: Cambridge, 2005, Print. Pradhan, Trilochan. The Photon. NY: Nova, 2001, Print. Read More