Current Research in Astronomy Essay Example for Free

Current Research in Astronomy Essay For many astronomers, Adaptive Optics is something like a dream coming true. Since 1609 and the first observations of celestial bodies performed with the help of an optical telescope, astronomers have always fought to improve the resolving power of their instruments. For a long time, engineers have trimmed the optical quality of the telescopes, until they finally reached the barrier set by the atmospheric turbulence. At that point, the intrinsic quality of the site became a major issue to establish new observatories with modern telescopes, and astronomers started to desert the urban skies and to migrate toward mountains and deserts (Alloin and Mariotti 2004 9). The recent emergence Adaptive optics aims at providing diffraction limited long exposure images at large telescopes, which is greatly considered as one of astronomy’s breakthrough (Alloin and Mariotti 2004 9; Espinosa 1997 12). By far, the largest limitation to the application of adaptive optics to astronomy is very limited sky coverage when using natural guide stars for wavefront sensing. Similar limitations existed for many military applications of adaptive optics (Espinosa 1997 12). Adaptive optics systems provide a real time correction of the distorted wavefronts; they restore all the properties of light prior to the final part of its travel through the atmosphere (Alloin and Mariotti 2004 9). Discussion Adaptive Optics: Wavefront and Laser Guide Star (LGS) Adaptive optic systems for atmospheric turbulence compensation require a reference star for correcting wavefront distortion. The sodium LGS relies on resonant backscattering of a laser tuned into the D2 sodium absorption line to provide a reference, but LGS must sufficiently bright to correct high order wavefront aberration (Zamorano, Gorgas and Gallego 2001 317). The key concept in adaptive optics is the wave front, which is found by tracing out an equal optical path (distance x refractive index) from a source to the region of interest. For a point source and free space, wavefronts are spherical, and for starlight, the distance is so large that for all practical purposes the wavefronts entering the Earth’s atmosphere are plane. After propagating through the random refractive index of the atmosphere, the wavefront entering the telescope pupil is random, and its statistics determine the image quality, and govern how an adaptive optical system might be used to compensate for the distortion (Agerorges 2000 4). Such effect greatly depends on the laser lunch power, polarization’s beam, atmospheric transmission and the sodium column density, which, if obtained appropriately, might even enhance the imagery, increase the scope of telescopic observatory, and improve the image details of pictures obtained from astronomical studies (Zamorano, Gorgas and Gallego 2001 317). The use of LGS AO has caught on quickly within the astronomical community in large part because, equipped with adaptive optics operating at the diffraction limit in the near-infrared, the new 6- to 10-m telescopes possess the capability to match the angular resolution in the Hubble Space Telescope (HST) in the visible and to exceed its resolution in the near infrared (Rodier 256). Laser Guide Star LGS, basically, is a technology that utilizes AO imaging in order to enhance graphical imagery of telescopes and view astronomical images with additional quality. The technology uses an artificial star in order to act as a wavefront reference source, which consequently corrects light distortion (Zamorano, Gorgas and Gallego 2001 317). The need for a bright stellar was always a concern for astronomical applications of adaptive optics. To operate, a wavefront sensor must have sufficient light to overcome photon noise and background noise with enough light left over to form the image. In astronomy, few stars of scientific interest are sufficiently bright. For imaging uncooperative satellites, reflected light is often too dim or nonexistent. In 1985, French astronomers Foy and Labeyrie published work detailing how one might use backscatter from a laser focused to a point in the atmosphere as an artificial beacon (a guide star) for astronomical adaptive optics. As work progressed in the astronomy community to build and test a laser powerful enough to have sufficient backscatter for the Foy-Labeyrie method (Tyson 2000 5). Since the beginning of the 1980s, classified U. S military work was addressing the problems of projecting high-energy laser beams from the ground to space for missile defense and secure communications. The research from 1982 at the U. S Air Force Starfire Optical Range (USAFSOR) directed by Robert Fugate advanced the laser guide star concept and produced a wealth information about laser performance requirements, adaptive optics system operation, atmospheric physics, and closed loop image of space borne objects. By 1991, the bulk of military work on laser guide starts was declassified and made available to astronomers around the world (Tyson 2000 5). Currently, LGS is being developed by various nations, setting up their own laser beacon and extensively enhancing research through the said technology. The use of a laser beacon as the reference source enables faint objects to be compensated by adaptive optics, at the expense of greater hardware complexity. The laser beacon must be directed within the isoplanatic angle of the science object at the observation wavelength; although, this procedure provide only short-exposure correction. On the other hand, a fixed natural guide star possesses the ability to further stabilized the image during long exposures so that sky coverage depends on the distribution of stars, which consequently enhances the space imagery (Hardy 1998 309). There are many cases where the object itself, such as a sunlit satellite, is insufficient for wavefront sensing. In astronomy, there are billions of stellar objects too dim for sensing and not near enough in the sky to bright objects. For high-energy laser propagation to uncooperative targets or satellite tracking and imaging, an artificial source must be placed above the atmosphere to provide photons for the wavefront sensor and subsequent compensation. Lasers actually provide only partial correction, because a natural star still is required and opposite tilt upon traveling up into the atmosphere and returning (Tyson 2000 6-7). Particularly exciting development is the use of adaptive telescope mirrors to compensate for the distortion of stellar images produced by atmospheric turbulence. Using adaptive optics, ground-based telescopes are now demonstrating diffraction-limited performance, albeit over relatively small fields of view. It can be expected that large ground-based telescopes will have higher resolution and light-gathering power than space-based telescopes, since both of these performance metrics depend on aperture size. Moreover, ground-based telescopes can be larger than those space-based ones; hence, enabling higher development and scope for stellar imagery. The adaptive optical system of LGS displays 0. 07-arcsecond resolution, which is almost a hundred times better than past ground-based telescope systems but uses a telescope built approximately 80 years ago (national Research Council 1998 137-138). Conclusion LGS AO is one of the breakthroughs of current astronomical imagery, which provides enhanced images and display features that are usually not present in the space-based telescopes, such as HCT. The mechanism involved utilizes a guide star or an artificial star that facilitates the graphical imagery. LGS works as distortion corrector enabling enhanced imaging through AO ground-based telescopes. Conclusion Ageorges, N. Laser Guide Star Adaptive Optics for Astronomy. Springer, 2000. Alloin, Danielle M. , and Jean-Marie Mariotti. Adaptive Optics for Astronomy. Springer, 2004. Espinosa, Jose. Instrumentation for Large Telescopes. Cambridge University Press, 1997. Flectcher, L. Solid State Laser for Subaru Laser Guide Star Adaptive Optics. Subaru Telescope. 6 July 2005. 8 Jan. 2008 www. nao. ac. jp/E/Outreach/pr-rl/2005/index. html. Flectcher, L. Observational Methods. 14 Feb. 2005. 8 Jan. 2008 http://www. astro. gla. ac. uk/users/lyndsay/TEACHING/A1OBSMETH/VIEWGRAPHS/starlight-figure1. jpg. Hardy, John W. Adaptive Optics for Astronomical Telescopes. Oxford University Press, 1998. National Research Council (U. S. ), . Harnessing Light: Optical Science and Engineering for the 21st Century. National Academies Press, 1998. Roddier, Francois . Adaptive Optics in Astronomy. Cambridge University Press, 1999. Tyson, Robert K. Adaptive Optics Engineering Handbook. CRC Press, 2000. Zamorano, Jaime, Javier Gorgas, and Jesus Gallego. Highlights of Spanish Astrophysics II. Springer, 2001.

Macrobiotics: A way of Life Essay -- Food Eating Vegan Essays

Macrobiotics: A way of Life WHAT IS MACROBIOTICS? Macrobiotics is not just a diet, but a holistic approach to living that takes into account all aspects of human life, including the inter-relationship between body, mind and spirit. Macrobiotics stresses the importance of a balanced diet because one's diet creates the foundation for a happy, healthy and harmonious life. Macrobiotic philosophy teaches practitioners to lead a balanced lifestyle based on the Chinese yin-yang principles. The actual macrobiotic diet closely resembles a vegan-like food pattern with virtually no animal food consumed. Practitioners also avoid "nonorganic" or "processed" foods. The macrobiotic movement has become increasingly popular during the past decade due to various survival stories from chronically ill persons who used the macrobiotic way as an alternative approach to medicine. WHAT IS THE PHILOSOPHY BEHIND MACROBIOTICS ? The "Process of Disease" explained through the seven stages of symptomology is the basis of macrobiotic theory with regard to people's eating habits and its effect on the human body. Macrobiotics applies yin-yang principles to explain the relationship between food and the human organism and a balanced diet. Macrobiotic philosophy defines a healthy person using three natural life processes as criteria: urination, bowel movements and breathing. When the body ingests toxins, as a result of an unbalanced diet, its natural healing process produces abnormalities in one or all of these three life processes. Most people naturally react to the situation by taking medicine to relieve the symptoms. According to practitioners of macrobiotics, the ingestion of pharmaceuticals only inhibits the body's ability to heal i... ...d be sufficient. Works Cited: Cambell, T.C., Parpia, B. & Chen,J. (1982). Diet, lifestyle and the etiology of coronary Artery disease: The Cornell China study. American Journal Cardiolog~v. 10B, 18T-21T. Dwyer, J.T., Dietz, W.H., Andrews, E.M. & Suskind, R.M. (1982) Nutritional status of Vegetarian children: American Journal of Clinical Nutrition. 35(2), 204-216. Furnham, A. & Forey, J. (1994).The attitudes behaviors and beliefs of patients of conventional vs. complementary (alternative) medicine: Journal of Clinical Psvchologv. 50(3), 458-469. van Stavern, W.A. & Dagnelie, P.C. (1988). Food consumption, growth, and development of Dutch children fed on alternative diets: American Journal of ClinicalNutrition. 48 (3 Suppl), 819-821. Weitzman, S. (1998). Alternative nutritional cancer therapies: International Journal of Cancer. 11(Suppl), 69-72.

How My Brother Leon Brought a Wie

A simple, faithful and responsible are some adjectives that described Ms. Lara May S. Aguilar. A kind of woman who’s prioritized her Family and Career. She is the only girl out of four siblings of Mr. Rogelio Aguilar and Mrs. Warlie Galvez Aguilar, that was born on May 06, 1986 at Pasig, Metro Manila. She is presently residing at Pag-asa District, Talavera Nueva Ecija where she spent all her childhood days until school days. She finished her elementary course at Talavera Central School year 1999, then her high school years at Talavera National High School year 2003. fter her graduation in high school, she think that she want to be a writer that is why in her college life, she chose a course that is related to what she want, and she decided to enroll Bachelor of Secondary Education Major in English at Nueva Ecija University Of Science and Technology. After her learning years, with the blessings of our almighty God, she passed the licensure examination for teachers on October 24, 2007 with a rating76. 20 % and this would be the greatest achievement she had. After passing the licensure examination for teachers, she started as a lecturer with hourly basis in NEUST main campus on June 2007to October 2011, then as a classroom teacher in Kobayashi Learning Center at Homestead II, Talavera Nueva Ecija on October 2012 to March 2013. Presently, she is an English course instructress at the very first College school in Talavera, the Nueva Ecija University Of Science And Technology- Municipal Government Of Talavera (NEUST-MGT).

Wuthering Heights By Emily Bronte - 1193 Words

Jieyi Zhang Ms. Power ENG1D7 Monday, January 12, 2015 Wuthering Heights, a novel written by Emily Brontà «, is true to its name. Wuthering, meaning a fierce wind, pertains to the wind stirring the souls of the two characters, Catherine Earnshaw and Heathcliff, and brings their emotions to extreme heights, which results in extreme behaviour and acting without thinking about the possible consequences. The main theme of this gothic romance novel is passion. The strong emotions such as love, hate, and desire that Catherine and Heathcliff feel for each other and the people around them controls their actions and makes their behaviour excessive, driving the story forward and generating action in the novel. The character depicted as most passionate is Heathcliff. His passion is dark and vengeful. Adopted into the Earnshaw family as a child, he grew up with Catherine. As they played together on the moors, unrestrained by responsibility and completely free, they developed feelings for each other. Heathcliff feels betrayed when Catherine decides to marry Edgar Linton instead of him. He had overheard Catherine’s conversation with Nelly, in which she’d said: â€Å"...did it never strike you that if Heathcliff and I married, we should be beggars?† (pg 97) Heathcliff’s feelings for Catherine is more than just love. He states, after Catherine’s death, â€Å"Be with me always - take any form - drive me mad! only do not leave me in this abyss, where I cannot find you! Oh, God! it is unutterable! I canShow MoreRelatedWuthering Heights By Emily Bronte1555 Words   |  7 Pages2015 Wuthering Heights (1847) by Emily Brontà « Introduction The novel Wuthering Heights was written in 1847 by Emily Brontà «. The plot unravels with Lockwood visiting his landlord at Wuthering Heights; as Lockwood stays the night, he starts to discover items within the home and later a fatal vision appears, which causes him great curiosity. Lockwood returns back to his residence at Thrushcross Granges and listens to the history of his landlord, Heathcliff; told by an old servant at Wuthering HeightsRead MoreWuthering Heights By Emily Bronte1521 Words   |  7 Pages  Wuthering Heights is Emily Brontà « s only novel. Written between October 1845 and June 1846, Wuthering Heights was published in 1847 under the pseudonym Ellis Bell; Brontà « died the following year, aged 30. Wuthering Heights and Anne Brontà « s Agnes Grey were accepted by publisher Thomas Newby before the success of their sister Charlotte s novel, Jane Eyre. After Emily s death, Charlotte edited the manuscript of Wuthering Heights, and arranged for the edited version to be published as a posthumousRead MoreWuthering Heights by Emily Bronte1290 Words   |  5 Pagesusually by retaliating in kind or degree† (â€Å"revenge†) however to Heathcliff it meant more than just to avenge himself he wanted to have everything he felt he rightfully deserved and more. Social class and revenge, are primary themes in the novel Wuthering Heights. Social class plays a considerable part in the lives and loves of the charters in the novel. Revenge is key element in the book, this twisted theme creates the whole plot line. â€Å"Children develop a strong interest in the world around them by theRead MoreWuthering Heights, by Emily Brontà «1865 Words   |  8 Pagesdevilish, preternatural passion that tamer beings can scarcely recognize as love.† (Duclaux) Wuthering Heights by Emily Brontà « is considered a masterpiece today, however when it was first published, it received negative criticism for its passionate nature. Critics have studied the novel from every analytical angle, yet it remains one of the most haunting love stories of all time. â€Å"Wuthering Heights is not a comfortable book; it invites admiration rather than love,† (Stoneman 1). The novel containsRead MoreWuthering Heights By Emily Bronte1936 Words   |  8 PagesWuthering Heights, a novel by Emily Bronte is one of the most admired and favorable written works in English literature. When the novel was published in the year 1847, it sold very poorly and only received a minimum amount of reviews. Although the novel does not contain any sexual relations or bloodshed, it is considered to be inappropriate due to its portrayal of an unconstrained love and cruelty. Wuthering Heights is formed on the Gothic tradition in the late 18th century, which consists of supern aturalRead MoreWuthering Heights by Emily Bronte553 Words   |  2 PagesWuthering Heights: Good vs. Evil Emily Bronte’s classical literary masterpiece, Wuthering Heights, can more or less be viewed as a struggle between conventional, civilized human behavior, as well as the wild, anarchistic side that each of us humans possess, although subtly. Bronte’s piece can be summed up by the â€Å"good vs. evil† elements that include Wuthering Heights as opposed to Thrushcross Grange, Heathcliff vs. Edgar, and much more. These elemental set points lead to the conclusion that WutheringRead MoreWuthering Heights by Emily Bronte885 Words   |  4 PagesIn â€Å"Wuthering Heights† Emily Bronte vividly present the main character, Heathcliff, as misanthropist after he suffers abuse, degradation, and loses his beloved Catherine. Heathcliff, a black, orphan gipsy child, is brought to live in upper-class society by Mr. Earnshaw’s generosity. Heathcliff is an outcast in his new society. Thus, Heathcliff’s temperament is depicted in â€Å"Wuthering Heightsâ⠂¬  as cruel, abusive, and vindictive against those who humiliated and not accepted him in society. HeathcliffRead MoreWuthering Heights By Emily Bronte1149 Words   |  5 PagesDuring it release in 1842, ‘Wuthering Heights’ by Emily Bronte was considered to be a novel of obscenity and monstrosity. The novel has the ability to adapt to a range of themes and transcend the forms of content and cultural context within the ideas of love, oppression, power and harmony. Critical readings of the text have challenged and enriched readers in a diverse array of interpretations of language and structure; forming personal meanings that have developed throughout history. England, inRead MoreWuthering Heights By Emily Bronte1208 Words   |  5 Pagesrepair, and spark one of the most largest human motivations: vengeance. If left unnoticed, the feeling will grow inside us and consume our every thought and ruin our lives. Therefore, leaving no remorse or peace for ourselves and others. Emily Bronte’s Wuthering Heights is a book about love that turns into vengeance and hatred that goes for generations. This story revolves around Heathcliff, an unmerciful vengeful man. His desire to pay back those who have done him wrong is so extreme that he finds himselfRead MoreWuthering Heights by Emily Bronte877 Words   |  4 PagesThe novel, Wuthering Heights, written by Emily Brà ¶nte, follows the stories of Catherine and Heathcliff Earnshaw. Both lived in Wuthering Heights, until Catherine went away to Thrushcross Grange and came back a changed person. The settings of Thrushcross Grange and Wuthering Heights, throughout the novel help to display the emo tions of the story, and shape the image of the people who live within them. The setting helps to describe aspects of the novel in greater depth. One of the first scenes of