Saturday, December 7, 2019

Traditional Litigation and the Non-Traditional Alternative Dispute Resolution free essay sample

There are many ways to handle a dispute. Many people chose to use the traditional litigation system, which are lawsuit being brought forth in the courts and some people choose alternative routes which may not always be involved in the court. The formal definition of traditional litigation is â€Å"the process of bringing, maintaining, and defending a lawsuit. This is also called judicial dispute resolution because courts are used to decide the case† (Cheeseman, 2010). Alternative Dispute Resolution is defined as â€Å"methods of resolving disputes other than litigation† (Cheeseman, 2010). Alternative Dispute Resolution By far the most common form of ADR is arbitration, however other types of ADR exist such as negotiation, mediation, conciliation, mini-trial, fact-finding, and the use of a judicial referee. â€Å"Negotiation is a procedure whereby the parties to a dispute engage in negotiations to try to reach a voluntary settlement of their dispute† (Cheeseman, 2010). Negotiations can go on for an extended amount of time to ensure that both parties are satisfied. We will write a custom essay sample on Traditional Litigation and the Non-Traditional Alternative Dispute Resolution or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Mediation is another type of ADR in which all parties involved in the issue select and agreed to use neutral third party that assumes the role of an intermediary that between both parties. The sole purpose of this intermediary is to facilitate a settlement between the parties. If an accord is reached by the disputing parties, then a settlement agreement is written and executed by the parties. Conciliation is a method of ADR frequently used when the parties involve do not wish to face each other in a confrontational venue. In this method an interested party known as a conciliator assists the party’s dispute to reach a settlement. The conciliator facilitates this process by the communicating offers and counter-offers of settlement between the two parties. Traditional Litigation System The traditional litigation system is where two parties (defendant and plaintiff) go forward in a court of law to solve a certain issue that they have with each other. In a traditional legal system the contents of the case publicity is not considered because adverse publicity is what is associated with litigation. The expenses in the traditional litigation system can become expensive and costly; this is the reason that some people chose Alternative Dispute Resolutions. Differences between Systems The two legal systems have some major differences. In the ADR system the resolution is usually less formal and less intimidating than in the traditional legal system. The resolutions are quicker and less expensive, the dispute is usually heard by an arbitrator or mediator and at the end of the â€Å"trail† the respondents will receive an opinion which can be filed with the court to become binding and turned into a judgment. The traditional legal system or trials are usually a more formal and slower process. The trials are more expensive because of the length of the trials. Trials are often heard before a judge and the judgments are binding through the court systems. Conclusion A person has to choose to decide which of the legal systems work best for them. It is important for a claimant to compare and contrast the impact that either of the systems would have on their particular situation.

Friday, November 29, 2019

Homosexuality Nature vs Nurture.The Study of How Essays

Homosexuality: Nature vs Nurture.The Study of How Biology and Society Influences Homosexual Identity DevelopmentThe concept of homosexuality is not a revolutionary one that it violates all cultural beliefs, gender and family roles, and societal values. The earliest documentation of homosexuality appeared in 600 B.C. in Asian cultures, and a few prominent historical figures such as Alexander The Great, Leonardo da Vinci, and Michelangelo were actually believed to be gay. In some cultures, homosexuals even hold a high status in society. For example, Native American tribes thought of homosexuals to be "spiritually gifted" and would look to them for spiritual advice and healing, indicating that it was a high honour to be gay in their community.However, homosexuality goes against many cultural beliefs, gender, and family roles that today's society values. As a direct result of going against social norms, homosexuals experience a lot of backlash that has led many to raise the question: Why do people continue to identify with being gay although they know the repercussions they may face in society? Is our sexuality a choice? Or are we born into our genders? Is our sexuality based on environmental factors or based on our own free will? The debate over the genesis of homosexuality has been ongoing for years and many argue that sexual orientation cannot be genetically hardwired. In this paper, I will be analyzing both aspects of the nature versus nurture debate in terms of the development of one's sexuality and will present research findings on the topic. I will be presenting evidence of biological influences, namely genetic and neurohormonal influences, on the development of homosexuality and will discuss the sociological view of socially influenced homosexuality. As the spectrum of research and studies conducted in this area is too wide, I will only be selecting a few points which I think are more interesting and relevant. I will also inject my own criticism of the theo ries and ideas discussed, evaluate the validity of the evidence, and apply sociological perspectives to the social elements. Theoretical OrientationI will be applying the symbolic interactionism theory to this topic and my research will be qualitative and on a micro-level and an international scale. Symbolic interactionism is relevant to my topic of discussion as it studies at the motivations behind one's sexual identity development.Symbolic interactionism is the sociological concept founded by Max Weber and it looks at how people attribute to, and construct meanings of their situations and behaviour. According to Weber, knowledge of cultural processes is only possible by understanding the meanings that the specific and shared reality holds for those involved. This includes the significance of subjective meaning and symbols in situations that are produced and represented. Blumer (1986) states that there are three tenets associated with symbolic interactionism. Firstly, people act to wards things based on the meanings it holds for them. For example, some people may view a tree as a sacred object while others see it as a particular botanical species or a source of lumber. Secondly, meanings of things are generated over time through human interaction. The significance of things are not individually determined or inherently linked to objects. Thirdly, meanings are modified during interaction through interpretive processes where an individual may change their initial interpretation of the situation. GENETIC INFLUENCE ON THE DEVELOPMENT OF HOMOSEXUALITYA study conducted by LeVay (1991) examined the interstitial nuclei of the anterior hypothalamus (INAH) in 19 gay men who had died from AIDS, 16 heterosexual men (six died from AIDS) and six heterosexual women (one died from AIDS). It was discovered that of all four sections of the INAH, only the third section was significantly larger in those with an attraction to women as compared to those with an attraction to men. H owever, the study neglected to include homosexual women and could not conclude if the size of the INAH-3 in a person is a cause or a consequence of sexual orientation. But it does provide evidence that there could be a biological reason why gay men and straight women are attracted to the same sex.Behavioural geneticists have also found that an identical twin of a homosexual has an approximate fifty percent chance of also being homosexual, while fraternal twins have approximately twenty

Monday, November 25, 2019

An Online MBA Improves a Job Candidate’s Chances Essays

An Online MBA Improves a Job Candidate’s Chances Essays An Online MBA Improves a Job Candidate’s Chances Essay An Online MBA Improves a Job Candidate’s Chances Essay Searching for a job is difficult enough without having a number of strikes against us. But when the competition is tough – as it often is – it helps to have as much on your side as possible, including experience, a strong track record of success, and a relevant education. In order to make themselves as marketable as possible, many people take the time to pursue an education beyond their four year college degree. An MBA especially can be extraordinarily appealing for an employer, as it shows dedication on the part of the prospective employee, and a commitment to staying on the cutting edge of business. Of course, for many people in this position, the pursuit of a traditional MBA may be logistically impossible. In terms of juggling a career, a family, and the myriad responsibilities associated with being an adult, earning another degree may fall significantly low on the priority list. But now, with the opportunities available through the Internet, adults can earn an online MBA without ever leaving their home. An online MBA is earned through the completion of coursework and reading on the computer; it is work that while certainly significant, can be completed at the leisure of the students rather than them rearranging their life to fit school. Better still, the result of an online MBA can be a significant edge on the competition in search of a job position.

Friday, November 22, 2019

Green Engineering Essay Example | Topics and Well Written Essays - 1250 words

Green Engineering - Essay Example The Durst Organization developed and constructed the Four Times Square in New York between 19996 and 1999 (â€Å"Wired New York Meetup Group† 1). There are 48 stories in the building, which makes it the newest, and the greenest skyscraper in Manhattan (â€Å"U.S. Department of Energy† 1). The building was the first green skyscraper in U.S, which continues to track its energy performance with Energy Star (â€Å"The Durst Organization† 1). Overview of Four Times Square Notably, the building presents the application of two principles of Green Engineering. These include principle 1, which reckons that designers need to strive to ensure that all material and energy inputs and outputs are as inherently safe as possible (Anastas and Zimmerman 96). It also presents principle 3, which claims that separation and purification operations should adopt a design that would minimize energy consumption and materials use (Anastas and Zimmerman 96). The Four Times Square building e ntails 1.6 million square feet of environmentally friendly architectural design. Indeed, this was the first green skyscraper and the second tallest building in the U.S. ... Department of Energy† 1). Upon completion, the Four Times Square reflected an environmentally responsible building where the designers examined the construction technology and all building systems for their impact on human health, environment sustainability, and energy reduction (Kaplan1). The evaluation made the building to be the first skyscraper to adopt state-of-the-art standards for energy conservation, indoor air quality, recycling systems, and the use of sustainable manufacturing processes (â€Å"Wired New York Meetup Group† 1). The Four Times Square has environmentally efficient gas-fired absorption chillers and a state of the art curtain wall with excellent shading and insulating performance (â€Å"Wired New York Meetup Group† 1). More so, the residents of the building are responsible of the building where the designers distributed a library of green information and environmental guidelines to the residents and the architects (Kaplan1). In addition, the t enants and their architects had substantial information on how to maximize the building as well as maintain the dream of the designers. Furthermore, the designers guaranteed lower operational costs upon the completion of the building. As such, we can establish that the Conde Nast Building adopts the principles of green engineering where it manifests quality and safe design as well as a promotion of the environmental, energy, and health factors. How the Four Times Square Works The Four Times Square adopts a low-energy design and renewable energy. The lighting at the building is very energy-efficient as it includes high performance fixtures with central controls. Notably, the designers used DOE-2 energy simulation modeling software to establish the most

Wednesday, November 20, 2019

QD1 Essay Example | Topics and Well Written Essays - 2750 words

QD1 - Essay Example The principal stakeholders within any business include the shareholders, employees, customers, suppliers, executives, board of directors, and the community in essence. It is a fact that business governance is a multi-faceted subject which takes into consideration the roles of all these pertinent positions (Suppert 2007). A business governance model consists of a number of broad categories which might include auditing, board and management structure and process, corporate responsibility and compliance, ownership structure and exercise of control rights, and financial transparency and information disclosure. The business governance plan is therefore exclusive and is very elaborate in its own right. The business governance regimes are deemed as important because these outline the need for understanding how a business is governed and what steps are necessary to undertake so that the business can bring about a great of deal for all the relevant stakeholders and for its own existence in th e future. The business governance tangents are therefore treated with a great amount of respect because it embodies the basis of achieving strategic objectives and goals. The different components of a business governance plan aim to study the basics related with the business realms. What this means is the fact that businesses will grow and expand further if the different components within their folds are taken care of in an amicable fashion. More than anything else, there is a dire need to understand how business governance would tie up the different stakeholders with the internal publics of the organization. It would also aim to touch upon the significant grey areas which are present within the business, and which might bring some sort of problems in the coming times. One must be sure that the business governance regimes are geared to bring in long term profits more than anything else, and there should be serious efforts and undertakings to make sure that success is guaranteed at t he end of the day. There must not be any compromise on this pointer at all, as has been demonstrated through research and evidence of related study. The business governance plan is a comprehensive one because it lists down the advantages of realizing new business opportunities as well as highlights the shortfalls and how these come about in the first place. What is most important is to know how work domains are manifested within the real sense of the word, and what the organizations are doing to bring success within their realms. The business governance realms require that the communication is done in such a way that there are no loopholes and shortcomings within the length of the corporations and the government. What this suggests is the fact that the business governance matters must have a very set hierarchical setting in place so that any issues that might arise within the future are taken care of in an adequate way. The two-tier boards are usually not very appreciable since thes e give some of the directors the right to vote, while others being at the same level still, are disallowed from the voting quarters. Then again, unitary boards are better since these have a single line of command which means that the decisions are taken by people whilst knowing beforehand who is the head and

Monday, November 18, 2019

Reflective Analysis Essay Example | Topics and Well Written Essays - 500 words

Reflective Analysis - Essay Example d, highlight and report similarities of results and methods of research that is done in a particular subject matter over the specified number of years. Following are the analyses of works which I have done in the recent years. Finally, this report is intended for my parents and will be used as a means of communicating my educational progress to them. The first assignment was written to highlight the development of electronic and digital means by which humans can now take notes. The work also noted the adverse influences of the abovementioned technological interventions as people are not being to write manually when they have to while they also fail to remember spellings and commit lots of grammatical mistakes and errors in punctuation. On the positive side, the fashion of digital noting helped the students in the learning process because they can accumulate obscene amount of information both effectively and efficiently (Wang, 2). The work also had quite a few grammatical errors of its own but I am trying to overcome my weaknesses in regard to grammar by writing on a more frequent basis. The second assignment was nothing new but a refined form of the first one in which I duly attempted to control and manage quality of the content whereas I also put significant level of effort in terms of studying the subject in more detailed manner. I added that digital note taking is better as it allows the audience to record information with less effort. And there is nothing wrong in adopting new sand improved methods of taking notes as conventional ones are going to become obsolete in a few years from now (Wang, 2). Finally, the work suggested all people to master both traditional and modern techniques of note taking (Wang, 3) so that they will become capable of doing that despite of having technological difficulties that may render their modern devices inoperable. This review and analytical paper was developed in order to put my thinking ability to test and I put my best

Saturday, November 16, 2019

Geometrical Optics And Its Applications

Geometrical Optics And Its Applications Optics is the cornerstone of photonics systems and applications. Geometrical optics, or ray optics, is to study the geometry of paths of lights and their imagery through optical systems. Light will be treated as a form of energy which travels in straight lines called rays. When light comes to be regarded as waves, it will be seen that shadows cast by objects are not as sharp as rectili (Ariel Lipson,Stephen G. Lipson,Henry Lipson) (Ariel Lipson,Stephen G. Lipson,Henry Lipson, 2010)near propagation suggests due to diffraction and interference effects of wave. Thus, there is a simple assumption for geometrical optics, which is rays of light propagate along straight lines until they get reflected, refracted, or absorbed at a surface. 2 Fermats Principle 2.1 Background Fermats Principle, also known as the principle of the shortest optical path, was introduced by Pierre de Fermat in the early seventeenth century. This principle is used to state and explain the motion of light ray through different media, which helps to demonstrate laws of reflection and refraction later on. 2.2 Theory The path of a light ray connecting two points is the one for which the time of transit, but not the length, is a minimum. The time, T , for a light ray through space to travel from a point A to another point B can be calculated as: It is known that is velocity, which can also be regarded as for light, where c is the speed of light and n is the refractive index of the medium. Thus, we have Then the path taken by light should be the path that minimizes this integral, which would be: Therefore, it is the fact that light will travel along paths of stationary optical path length, where the optical path length is a local maximum or minimum with respect to any small variation in the path. And many paths will take exactly the same time to travel from point A to point B. (Ariel Lipson,Stephen G. Lipson,Henry Lipson, 2010) 3. Reflection 3.1 Derivation for Law of Reflection In general, law of reflection states that when a light ray incident upon a reflective surface, it will be reflected with an reflective angle that exactly equal to the incident angle with respect to the normal of the surface. Law of reflection can be dervied from Fermats Principle. Assume that the medium of the light travel is homogeneous, we haveC:UsersGaryDesktopà ¦Ã…“ ªÃƒ ¥Ã¢â‚¬ËœÃ‚ ½Ãƒ ¥Ã‚ Ã‚ .png Total path length S from A to B is Based on Fermats Principle we know that light would travel the path with minimum time. As in homogeneous medium, light travels with a constant speed and therefore the minimum time path is equilvant to the minimum distance path, which can be obtained by taking the first derivative of S with respect to x. which is sinà £Ã¢â‚¬Å¾Ã‚ ¥AOC = sin à £Ã¢â‚¬Å¾Ã‚ ¥BOC Thus shows that à £Ã¢â‚¬Å¾Ã‚ ¥AOC = à £Ã¢â‚¬Å¾Ã‚ ¥BOC, the angle of incidence equals the angle of reflection NB: It has to be reminded that the incident ray, the refracted ray and the normal are co-planar. (Philip D. Straffin, C. T. Benson, 1993) 3.2 Specular and Diffuse Reflection In details, there are two types of reflection Specular reflection and diffuse reflection. Specular or regular reflection is said to occur when parallel rays reflect from a high smooth and flat surface. For instance, a flashlight beam is said to have specular reflection as the reflective surface is mirror which is highly smooth and it, hence, makes the reflected beams travel towards the same direction in parallel as in (a). Most object, however, reflect light diffusely and the rays in an incident parallel beam are reflected in many direction as in (b) because of diffuse reflection. Diffuse reflection is due to the surface of the object not being perfectly smooth like a mirror. In fact, under microscopic scale, the surface of most of objects, if not all, is quite rough. Although at each point on the surface the law of reflection is observed, the angle of incidence and the angle of reflection varies from point to point. Each of the initially parallel rays, therefore, is reflected in a different direction. 3.3 Mirror Concepts and its Applications 3.3.1 Image Formation with Mirrors Mirrors, undoubtedly, are ubiquitous in daily, especially used in mirror and optical instruments for gathering light and forming images. Law of reflection can be applied to use in locating the reflected image graphically as long as the size, location and orientation of the object is known. Images in Plane Mirrors Images with mirrors are formed when many non-parallel light beams are reflected from the mirror surface and converge to form a corresponding image point. Image formed by plane mirror is erect, virtual, same size as the object and laterally inverted.C:UsersGaryDesktopreflection in mirror.png For a point object, in Fig, rays from the object at O are reflected in all directions based on the laws of reflection so that they appear to come from a point I behind the mirror and this is where the observer imagines the image to be. For an extended object, in Fig, the image of a point A on the object is at A, and two points are being equidistant from the mirror. Similarly, the image of point B is at B. The image size, therefore, is identical to the object seize, giving a magnification of unity. However, the right-hand side of the object becomes the left-hand side of the image and vice versa. The image is said to be laterally inverted.C:UsersGaryDesktopmirror extended object.png To conclude, a planar mirror is strictly stigmatic in nature Any incident rays issued from point A gives reflected rays passing through point B symmetrically to A with regard to the plane of the mirror. B, hence, is the image of A. (Katz, 2002) Images in Curved Mirrors There are mainly two types of spherical mirrors, concave and convex. Similar to planar mirror, image can be traced using the law of reflection. Unlike image formed by planar mirror, which is always erect, virtual, same size as the object and laterally inverted, the image formed by a spherical mirror and its nature depend on the distance of the object from the mirror. To construct the image, we assume that small objects on the principal axes of mirrors of small aperture are being considered so that all rays are paraxial. Point images will, thus, be formed of points on the object. For concave mirrors, also known as converging mirrors because of their action on a parallel beam of light, is a mirror with a curved reflecting surface that bulges inward. The formation of image using concave mirror can be in different locations of the object can be concluded by the following figure. Concave Mirror The nature of image using concave mirror and its applications are summarized as below: Position of the object Position of the image Nature and size of the image Use At infinity At the focus Real, inverted and diminished As collector of radiation in solar heating devices Beyond the centre of curvature Between the focus and the centre of curvature Real, inverted and diminished At the centre of curvature At centre of curvature Real, inverted and same size as object As a reflecting mirror behind a projector lamp Between the focus and centre of curvature Beyond the centre of curvature Real, inverted and magnified In flood lights At focus At infinity Real, inverted and magnified As a reflecting mirror in car, head lights, search lights etc. Between the pole of the mirror and the focus Appears behind the mirror Virtual, erect and magnified As a shaving mirror or makeup mirror and dentists mirror (Katz, 2002) For convex mirrors, also known as diverging mirrors reflect the incoming parallel light beams to form divergent beams which appear to come from a point behind the mirror.Convex Mirror Unlike that in concave mirrors, the nature of image formed by convex mirror is always virtual, diminished and erect. (Katz, 2002) 3.3.2 Derivation of the mirror formula Mirror formula is useful when we have to calculate the image location. Using triangles 2 and 3, we have, While using trangles 2 and 4, we have, Where is the image distance, is the object distance, f is the focal length, is the image height and is the object height It should be noticed that the sign convention is to be used in mirror formula. A real object or image distance is positive while a virtual object or image distance is negative. Magnification of a mirror image, m, can also be calculated by 3.3.3 Mirror instruments Catoptric Systems Catoptric Systems is the system that merely consists of mirrors for the formation of image. (Board, 2012) Newtonian telescope Newtonian telescope is the first reflecting telescope invented by Isaac Newton in 1668. It consists of a concave primary mirror and a small flat diagonal secondary mirror. In a bid to have a stigmatic axial image, a concave mirror has to be applied to act as a primary mirror and it reflects light back up the scope axis to the secondary mirror which is titled at 45o to the axis. The secondary mirror, which is a small plane mirror, is placed in the path of beams reflected by the primary mirror in order to divert the rays to one side of the tube. The reason for choosing a small mirror to act as secondary mirror is to prevent the influx of light beams is blocked from reaching the primary mirror. Pros of the Newtonian telescope Cons of the Newtonian telescope Less expensive Reduction of light intensity due to the blockage of central flat plane Shorter focal ratio leads a wider field of view Easily suffer from coma (i.e. an off-axis aberration) Free of chromatic aberration Simpler fabrication (Kitchin, 2012) Cassegrain Telescope Cassegrain Telescope is another type of reflecting telescope employing two principal mirrors, a concave parabolic primary mirror like the Newtonians, but its secondary one is a convex hyperboloidal mirror. It makes use of the special properties of parabolic and hyperbolic reflectors. A concave parabolic reflector will reflect all incoming light rays parallel to its axis of symmetry to a single point, the focus. A convex hyperbolic reflector has two foci and will reflect all light rays directed at one of its two foci towards its other focus. The mirrors in this type of telescope are designed and positioned so that they share one focus and so that the second focus of the hyperbolic mirror will be at the same point at which the image is to be observed, usually just outside the eyepiece. The parabolic mirror reflects parallel light rays entering the telescope to its focus, which is also the focus of the hyperbolic mirror. The hyperbolic mirror then reflects those light rays to its other focus, where the image is observed. (Waland, 1990) Gregorian telescope Gregorian telescope employs concave parabolic mirror to act as both primary and secondary mirror in this reflecting telescope. The light that first enters the tube is reflected by the primary concave mirrors and directed towards the secondary mirror, which is also a concave mirror. It will reflect the rays out to the telescope through the hole in its center. Observer can therefore view the image formed on the eyepiece. (Trà ¼mper, 2010) Catadioptric Systems Catadioptric system, on the other hand, is the system that consists of both mirrors and lenses for the formation of image. (Board, 2012) Catadioptric Systems will not be included in this paper. 3.4 Other Applications 3.4.1 Optical lever and light-beam galvanometers Galvanometer is an instrument that used to measure very small electric currents. Some sensitive galvanometers would use a beam of light in conjunction with a small mirror as a pointer. When there exists current flowing in the electric wire, a tiny mirror that is fixed to the part of the meter will rotate. And a light beam from a fixed lamp falls on the mirror and is reflected onto a translucent scale. For a given current, the longer the pointer (i.e. the reflected beam) the greater the deflection observed on the scale. This simply applies the reflective nature of light wave. (A.M.Badadhe, 2006) 3.4.2 Red-eye effect The Red-eye effect is a common phenomenon in photography. It occurs when the photographic flash unit place closely to the camera lens. Normally, the rationale of photo-taking is that light from the flash unit enters the eye and is reflected back to the camera lens. Nevertheless, under dark environment, pupil diameter would increase due to contraction of radial muscle fibers and relaxation of circular muscle fibers of iris under autonomic nervous system and therefore more light beams can enter into the retina of the eye. And the reflected light from the retina is red because of largely blood vessels in Choroid. It, therefore, gives the Red-eye effect in photograph. 3.4.3 Headlight of Car It employs concave parabolic mirrors at the front of the car, which acts as reflectors in the head lights of cars, search lights etc. 3.4.4 Dentists Mirror Dentists Mirror applies reflection to reflect and focus light on the tooth so that dentists can be examined in detail. 3.4.5 Optical Comparator Optical Comparator is an instrument that projects a magnified image or profile of a part onto a screen for comparison to a standard overlay profile or scale based on the principles of optics. The comparator, basically, is a non-contact device, which frequently used to measure, test, inspect, gauge or examine parts for compliance with specifications. (A.M.Badadhe, 2006) 3.4.6 Security Convex Mirror One of the distinguish feature of convex mirror is the widely view range. Therefore, convex mirror is applied to act as a security mirror in blind junctions of roads or at corners of walls of bug buildings. The person that is approaching from other side would be shown when the mirror is positioned properly. 3.4.7 Rear-view mirror in an automobile Knowing that the size of image of an object would be smaller when the object comes closer to the convex mirror, this unique feature can be applied to use on automobiles as rear view mirrors so that the diver can clearly view an approaching vehicle. 3.4.8 Submarines PeriscopeC:UsersGaryDesktopreflecting Periscope.png A periscope is a mirror instrument for observation from a concealed position. It works by employing two mirrors at 45o to each other, reflecting light rays from one place to another and finally out to the persons eye. 4 Refraction 4.1 Law of Refraction Qualitatively, when a light wave, which in fact composed of oscillating Electric fields and Magnetic field, crosses from a low optically density medium, say vacuum into a high optically density medium, say glass, E-Field and B-Fields are altered in terms of magnitude and direction of travel by the charges in the glass. Law of refraction, however, can be proved mathematically as follows: The first medium is supposed to be faster than the second medium and the speeds of propagation in 1st medium and 2nd medium are and respectively, where c is the speed of light in vacuum and n1, n2 à ¢Ã¢â‚¬ °Ã‚ ¥ 1. C:UsersLenovoDropboxU life2012-13, year2, 1st semesterCCST 9042 The world of wavesSnellslaw_diagram2.png Then, we have to evaluate the time taken by light ray from P to Q, which is Based on Fermats Principle, light travels the path with the least time. Thus, in an attempt to minimize the transit time, we set the derivative of time is zero and we have: By trigonometry, we have As and, we have This is Law of refraction, also known as Snell-Descartes law. NB: Similar to law of reflection, the incident ray, the refracted ray and the normal are co-planar. (Philip D. Straffin, C. T. Benson, 1993) 4.2 Total internal reflection According to Snells law, when a light travels from one a medium with a higher optical density, to a medium with a lower optical density, say from glass to air, it will be refracted away from the normal (i.e. Ray C in Fig 4.2a) and a weak internally reflected ray is, meanwhile, formed (i.e. Ray B in Fig 4.2a) C:UsersGaryDesktopà ¦Ã…“ ªÃƒ ¥Ã¢â‚¬ËœÃ‚ ½Ãƒ ¥Ã‚ Ã‚ 33.png Increasing the angle of incidence i increases the angle of refraction r, and at a certain angle of incidence c, called the critical angle, the reflected ray beam just emerges along the surface of the glass and the angle of refraction is 90o (i.e. Ray D in Fig 4.2b). In Fig 4.2 c, as the incident angle is increased continuously above critical angle (i.e. i > c), the refracted angle will be higher than 90o and sin r > 1, which is impossible and no refraction is possible. At this stage the internally reflected ray becomes bright and the refracted ray disappears. Hence, total internal reflection is now said to be occurring since all the incident light is reflected inside the optically denser medium. Mathematically, the critical angle can be found based on Snells law, which is Assume that n1 is refractive index of optically denser medium, n2 is refractive index of optically less dense medium, ÃŽÂ ¸1 is the critical angle of denser medium and ÃŽÂ ¸2 is the angle of refraction in less denser medium. All in all, for Total internal reflection to happen: Light must travel from denser medium to rarer medium. Angle of incidence should be greater than critical angle (i.e. i > c.) 4.3 Thin Lenses Thin lens is a lens that its axial thickness is small compared to the radii of curvature of its surfaces. (I.e. The thickness of the lens is negligible compared with the focal length of the lens) There are mainly two types of thin lenses, Converging thin lenses and Diverging thin lenses. Converging thin lenses, also known as convex lenses, direct parallel light rays bending toward one another after passing through them Diverging thin lenses, or so-called concave lenses, cause parallel light beams to spread as the leave the lens. 4.3.1 Image Formed by Thin Lenses Convex Lens Ray DiagramFormation of Image by a Convex Lens Object is located between focus and lens The image is: Virtual Erect Magnifiedobject at F1 2. Object is located at focus The image is: Real Inverted Magnified 3. Object is located between focus and F2 The image is:object between F2 F1 Real Inverted Magnified 4. Object is located at F2object between O F2 The image is: Real Inverted Same size as the object 5. Object is located beyond F2object beyond F2 The image is: Real Inverted Diminished 6. Object is located at infinityobject infinity The image is: Real Inverted Highly diminished Concave Lens Ray Diagram 1. Object is located between focus and mirrorconcave lens object F O The image is: Erect Virtual Diminished 2. Object is located between mirror and infinityconcave lens object infinity O The image is: Erect Virtual Diminished 3. Object is located at infinityconcave lens object at infinity The image is: Erect Virtual Diminished 4.3.2 Derivation of the lens formula for thin lenses Gaussian lens formula, also known as lens formula, can be derived as follow: As, (1) Where O is the size of the object and I is the size of the image. Also, Thus, Combine with (1), we have NB: The Cartesian Sign Convention for thin lens formulas are as follow: Light travels initially from left to right toward the lens. Object distance p is positive for real objects located to the left of the lens and negative for virtual objects located to the right of the lens. Image distance q is positive for real images formed to the right of the lens and negative for virtual images formed to the left of the lens. The focal length f is positive for a converging lens, negative for a diverging lens. The radius of curvature r is positive for a convex surface, negative for a concave surface. Transverse distances are positive above the optical axis, negative below (Katz, 2002) 4.3.3 Power of a Lens The optical power of the lens is used to describe the bending ability of lens in term of power. Basically the power of a lens of focal length f is, Power, in the case, can be expressed in m-1as the unit of power is diopter 1 D = 1m-1 Therefore, if there exists a convex of power 1D, its focal length equals to 1 meter. 4.4 Optical instruments 4.4.1 Prisms Optical prisms are components that commonly used in optical experimental arrangements and optical instruments, with the role of illustrating dispersion of light beams. Rather than showing the complicated mathematical proof such as derivation of minimum deviation, application of prism will be illustrated below. (Thorington, 2009) Prism BinocularsC:UsersGaryDesktopprism.png Prism Binoculars consist of a pair of refracting astronomical telescopes with two totally reflecting prisms (angles 90o, 45o, and 45o) between each objective and eyepiece. Prism A causes lateral inversion and prism B inverts verticallt so that the final image is the same way round and the same way up as the object. (Thorington, 2009) PeriscopeC:UsersGaryDesktoppp.png Periscope, apart from using two reflecting mirror, employs two prisms. Under the occurring of total internal reflection on the hypotenuse, the incident rays and reflected rays are symmetric with regard to a plane orthogonal to the hypotenuse. In the case of normal incidence on one side of the right angle, the incident and reflected beams are orthogonal. 4.4.2 Magnifying Glass Magnifying glass, also called Simple microscope, consist of a converging lens forming a virtual, upright, magnified image of an object placed inside its principal focus. For an object of height h is viewed at the near point by the unaided eye, the visual angle is, where D is the least distance of distinct vision Now the object is placed at distance u from the lens, the visual angle subtended by its image is given by The angular magnification is, therefore, given by 4.4.3 Compound Microscope Compound Microscope is a kind of optical instrument that uses visible light and a lens system to magnify images of small samples. C:UsersGaryDesktopcompound micropound.png The lens L1 nearer to the object, called the objective, forms a real, magnified, inverted image I1 of an object O placed just outside its principal focus Fo. I1 is just inside the principal focus Fo of the second lens L2, called the eyepiece, which act as a magnifying glass and produces a magnified, virtual image I2 of I1. In normal adjustment, the final image I2 lies at the near point. Then the visual angle subtended by the final image to the eye is given by When the object of height h is placed at the near point and viewed unaided, the visual angle subtended by the object is given by Hence, the angular magnification is given by And since, the linear magnification is equal to the linear magnification of the objective x linear magnification of the eyepiece. (Giordano, 2011) 4.4.4 Refracting Astronomical Telescope Refracting Astronomical Telescope consists of two converging lenses; one is an objective with long focal length and the other an eyepiece with short focal length. The objective L1 forms a real, diminished, inverted image I1, of a distant object at its principal focus Fo since the rays incident on L1 from a point on such an object can be assumed parallel. The eyepiece L2 acts as a magnifying glass and forms a magnified, virtual image of I1 and, when the telescope is in normal adjustment, this image is at infinity. I1 must, therefore, be at the principal focus F2 of L2, hence F0 and F2 coincide. From the above figure, we find that The visual angle subtended by the object is given by and the visual angle subtended by the object is given by, where h is the image height. Therefore, the angular magnification is For telescope in normal adjustment, the separation of the two lenses is the sum of the focal lengths. And this, the foci of the objective lens and the eye-piece must be at the same place. (Giordano, 2011) 4.4.5 Galilean Telescope Galilean Telescope consists of two lenses a converging objective of large focal length and a diverging eyepiece of small focal length The angular magnification is 5. Conclusion In this term paper, the concepts of geometric optics are included comprehensively such as law of reflection, refraction, formation of images in mirrors and lens, etc. The notion of a light ray and the scientific study of light are involved in a bid to illustrating the working principle of different mirror and optical instruments, such as various telescope, efficiently.