On Halos, Mirages and Other (Atmospheric) Architectural Events
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Atmospheric Optics - II First Midterm Exam Is This Friday!
Atmospheric Optics - II First midterm exam is this Friday! The exam will be in-class, during our regular lecture • this Friday September 28 at 9:30 am The exam will be CLOSED BOOK • ♦ No textbooks ♦ No calculators ♦ No cheat-sheets Alternate seating • The grades will be posted on WebCT • The exam covers Chapters 1,2,3,4,5, and 19. • The sections which are not covered are listed on the • Class Notes web page. RECAP • Human perception of color, white objects, black objects. Light scattering: light is sent in all directions –forward, sideways and • backward ♦ Geometric scattering: R>>λ (all wavelengths equally scattered) ♦ Mie scattering: R~λ (red is scattered more efficiently) ♦ Rayleigh scattering: R<<λ (blue is scattered more efficiently) Phenomena: white clouds, blue skies, hazy skies, crepuscular rays, colorful • sunsets, blue moon. TODAY: Refraction: the bending of the light ray as it travels from one medium to • another. It bends towards the vertical if it enters a more-dense medium and away from the vertical as it enters a less-dense medium. ♦ Phenomena: stars appear higher in the sky, twinkling, twilight. • Reflection: the angle of incidence is equal to the angle of reflection • Total internal reflection: mirages Dispersion: separation of colors when light travels through a medium. • ♦ rainbow Reflection and Refraction of Light The speed of light in vacuum • is c=300,000 km/s Snell’s law: The angle of • incidence is equal to the angle of reflection. Light that enters a more- • dense medium slows down and bends toward the normal. Light that exits a more- • dense medium speeds up and bends away from the normal. -
Mystic Mountain © Mendip Hills AONB
Viewpoint Mystic mountain © Mendip Hills AONB Time: 15 mins Region: South West England Landscape: rural Location: Ebbor Gorge, Somerset, BA5 3BA Grid reference: ST 52649 48742 Getting there: Park at Deer Leap car park and picnic area (on the road between Wookey Hole and Priddy) Keep an eye out for: Buzzards and other birds of prey soaring on the thermals below From this stunning vantage point we have sweeping views south across the flat land of the Somerset Levels. On a clear day, looking east you can see the dark line of hills marking out Exmoor National Park and if you look in a west south-west direction you can even spot the Bristol Channel glistening in the distance. As our eyes pan across the view they rest on a perfectly rounded knoll with a short tower on top. This is Glastonbury Tor. Claimed as the site of the legendary Vale of Avalon and the final resting place of King Arthur, the tor rises up above the flat land surrounding it and is visible for miles around. Why does the mystical Glastonbury Tor rise up out of the surrounding lowlands? First of all look straight ahead and in the middle distance you’ll see three hills which punctuate the flat landscape. From left to right they are Hay Hill, Ben Knowle Hill and Yarley Hill, part of a low ridge just south of the River Axe. Surrounding these hills the Somerset Levels are an area of low-lying farmland. The lowest point is just 0.2 metres above sea level. -
The Min Min Light and the Fata Morgana Pettigrew
C L I N I C A L A N D E X P E R I M E N T A L OPTOMETRYThe Min Min light and the Fata Morgana Pettigrew COMMENTARY The Min Min light and the Fata Morgana An optical account of a mysterious Australian phenomenon Clin Exp Optom 2003; 86: 2: 109–120 John D Pettigrew BSc(Med) MSc MBBS Background: Despite intense interest in this mysterious Australian phenomenon, the FRS Min Min light has never been explained in a satisfactory way. Vision Touch and Hearing Research Methods and Results: An optical explanation of the Min Min light phenomenon is of- Centre, University of Queensland fered, based on a number of direct observations of the phenomenon, as well as a field demonstration, in the Channel Country of Western Queensland. This explanation is based on the inverted mirage or Fata Morgana, where light is refracted long distances over the horizon by the refractive index gradient that occurs in the layers of air during a temperature inversion. Both natural and man-made light sources can be involved, with the isolated light source making it difficult to recognise the features of the Fata Morgana that are obvious in daylight and with its unsuspected great distance contribut- ing to the mystery of its origins. Submitted: 11 September 2002 Conclusion: Many of the strange properties of the Min Min light are explicable in terms Revised: 2 December 2002 of the unusual optical conditions of the Fata Morgana, if account is also taken of the Accepted for publication: 3 December human factors that operate under these highly-reduced stimulus conditions involving a 2002 single isolated light source without reference landmarks. -
The Antarctic Sun, December 17, 2006
December 17, 2006 New fi nds in Dry Valleys indicate ancient tundra By Peter Rejcek Sun staff Flannel shirts and jeans – or perhaps a light fleece – may have been the norm in the McMurdo Dry Valleys of Antarctica about 14 mil- lion years ago. Fossil records and glacial history in an area of the western Olympus Range near Mount Boreas indi- cate that during the middle of the Miocene epoch (about 14 million years ago) climatic conditions were warm and wet enough to support plant and insect life, according to a team of scientists that returned this season to continue its research. The story began when Adam Lewis, a post-doctoral fellow at The Antarctic The Sun Byrd Polar Research Center at The Ohio State University, traversed a roughly 100-square-kilometer Allan Ashworth picks through a pile of area of the Olympus Range sev- Peter Rejcek / eral years ago while working on shale looking for fossils and other his doctorate. His thesis involved fleshing out the glacial history evidence of a tundra environment that he and of eight valleys between various mountain peaks. others believe disappeared in the McMurdo Dry “In the process of doing that, I discovered these lake deposits,” Valleys about 14 million years ago. explained Lewis shortly before he headed into the field via helicop- See related story on page 8 See CLIMATE on page 9 Blowin’ in the Wind Quote of the Week USAP looks to harness alternative energy for McMurdo, South Pole “So, are you originally from By Steve Martaindale Programs for the National Science Foundation. -
The Fata Morgana. by Professor FA Forel, Morges
1911-12.] The Fata Morgana. 175 XV.—The Fata Morgana. By Professor F. A. Forel, Morges, Switzerland. Abstract of an Address delivered before the Society on July II,., 1911; translated by Professor C. G. Knott. AMONG optical phenomena which originate over the surface of water there is one so ill-defined and ill-observed as to be still mysterious; till now it has received no valid explanation. The Italians call it the Fata Morgana. Under conditions still lacking precise description, there appear on the far side of the Straits of Messina certain fantastic visions, fortresses and castles of unknown cities, which seem to emerge from the sea, soon to vanish again. These are the "palaces" of the "fairy Morgana," which appear and dis- appear at the capricious stroke of the magician's wand. Most of the accounts of the phenomenon are founded on the extravagant description and the amazing picture published in 1773 by the Dominican friar Don Antonio Minasi, professor of botany at the Roman College of Sapienzia. This drawing, with its incoherent groupings of castles and boats, reflected and refracted at random in a manner quite inconsistent with physical possibilities, was largely the creation of the distorted imagination of an artist who did not understand in the least the wonderful illusion. To appreciate the confusion which reigns in the scientific world in regard to this phenomenon, the reader need only refer to the chapter on the Fata Morgana in Pernter's admirable work on Meteorological Optics (Vienna, 1910). There he will be impressed with the uncertainty of the conclusions reached by the author after a study of the insufficient and contradictory documents to which he had access. -
Storms, Swells, Snowand Ice (Topped with Polar Bears)
travel at home travel at home INTO THE NORTH Storms, swells, snow and ICE and OUT OF THE (topped with polar bears) are NORTHWEST PASSAGE all part of this EPIC voyage STORY + PHOTOGRAPHY BY Barb Sligl Iceberg at sunset, 250 km north of the Arctic Circle in Ilulissat Icefjord in Greenland, a UNESCO World Heritage Site 36 JUST FOR CANADIAN DENTISTS November/December 2016 travel at home travel at home omewhere above the Arctic Circle, I see a fata morgana. Low-lying, barren islands—like so many sperm whales with their broad, sloping foreheads—float above the horizon in Coronation Gulf. As if I’m a long-lost sea captain of yore, it’s a glimpse of what’s called a superior mirage. In 1818, on his search for the long-sought Northwest Passage, captain John Ross’s route was barred by an insurmountable range he called Croker’s Mountains. Yet there was no such thing. A year later, another explorer sailed right through the same spot in Lancaster Sound, as did doomed Franklin in 1845 and then the first man to make it through the SNorthwest Passage in 1906, Roald Amundsen. Today, this storied route is often still blocked—by sea ice. It’s what makes it one of the last untouched places on earth. I’m on Adventure Canada’s Out of the Northwest Passage voyage, and after my fata morgana sighting, I continue to see fantastical things over the next 16 days of this historic- yet-still-novel voyage. From a strip of pink on the horizon that hovers between inky sea and dark swathe of clouds like a Rothko painting to storms and swells, snow and ice—all High Arctic sunset, like a Rothko painting Touring Ilulissat Icefjord by zodiac with the seductive whisper of peril. -
Catalogue of Place Names in Northern East Greenland
Catalogue of place names in northern East Greenland In this section all officially approved, and many Greenlandic names are spelt according to the unapproved, names are listed, together with explana- modern Greenland orthography (spelling reform tions where known. Approved names are listed in 1973), with cross-references from the old-style normal type or bold type, whereas unapproved spelling still to be found on many published maps. names are always given in italics. Names of ships are Prospectors place names used only in confidential given in small CAPITALS. Individual name entries are company reports are not found in this volume. In listed in Danish alphabetical order, such that names general, only selected unapproved names introduced beginning with the Danish letters Æ, Ø and Å come by scientific or climbing expeditions are included. after Z. This means that Danish names beginning Incomplete documentation of climbing activities with Å or Aa (e.g. Aage Bertelsen Gletscher, Aage de by expeditions claiming ‘first ascents’ on Milne Land Lemos Dal, Åkerblom Ø, Ålborg Fjord etc) are found and in nunatak regions such as Dronning Louise towards the end of this catalogue. Å replaced aa in Land, has led to a decision to exclude them. Many Danish spelling for most purposes in 1948, but aa is recent expeditions to Dronning Louise Land, and commonly retained in personal names, and is option- other nunatak areas, have gained access to their al in some Danish town names (e.g. Ålborg or Aalborg region of interest using Twin Otter aircraft, such that are both correct). However, Greenlandic names be - the remaining ‘climb’ to the summits of some peaks ginning with aa following the spelling reform dating may be as little as a few hundred metres; this raises from 1973 (a long vowel sound rather than short) are the question of what constitutes an ‘ascent’? treated as two consecutive ‘a’s. -
Introduction: to Be a Shapeshifter 1
NOTES Introduction: To Be a Shapeshifter 1 . Sir Thomas Malory, Malory: Works , ed. Eugene Vinaver (Oxford: Oxford University Press, 1978 ), 716. 2 . Carolyne Larrington, for example, points out that “Enchantresses . sometimes . support the aims of Arthurian chivalry, at other times they can be hostile and petty-minded.” See King Arthur’s Enchantresses: Morgan and Her Sisters in Arthurian Tradition (New York: I. B. Taurus, 2007), 2. While Larrington’s book provides a review of many of Morgan’s literary appearances, my study focuses on close reading, attention to translation issues, and discussion of social concerns. In her review of Larrington’s King Arthur’s Enchantresses: Morgan and Her Sisters in Arthurian Tradition , Elizabeth Archibald laments that “it would have been interesting to hear more about the ways in which Arthurian enchantresses do or do not resemble their Classical precursors, or indeed Celtic ones, in their use of magic and in their challenges to male heroic norms.” See Elizabeth Archibald, “Magic School,” Times Literary Supplement (February 2, 2007), 9. My study answers this cri- tique by reexamining pivotal scenes in critical texts and by dismantling the archetypal approach that Larrington follows. 3 . Norris J. Lacy, ed., The Fortunes of King Arthur (New York: D. S. Brewer, 2005 ), 94–95. 4 . Helaine Newstead, Bran the Blessed in Arthurian Romance (New York: AMS Press, 1966 ), 149. 5 . Elisa Marie Narin, “‘Þat on . Þat oÞer’: Rhetorical Descriptio and Morgan La Fay in Sir Gawain and the Green Knight ,” Pacific Coast Philology 23 (1988): 60–66. Morgan only partly fits the description of a supernatural ‘enemy’ provided by Hilda Ellis Davidson and Anna Chaudri; see n. -
Gramophone, Film, Typewriter
EDITORS Timothy Lenoir and Hans Ulrich Gumbrecht GRAMOPHONE, FILM, TYPEWRITER FRIEDRICH A. KITTLER Translated, with an Introduction, by GEOFFREY WINT HROP-YOUNG AND MICHAEL WUTZ STANFORD UNIVERSITY PRESS STANFORD, CALIFORNIA The publication of this work was assisted by a subsidy from Inter Nationes, Bonn Gramophone, Film, Typewriter was originally published in German in I986 as Grammophon Film Typewriter, © I986 Brinkmann & Bose, Berlin Stanford University Press Stanford, California © I999 by the Board of Trustees of the Leland Stanford Junior University Printed in the United States of America erp data appear at the end of the book TRANSLATORS' ACKNOWLEDGMENTS A translation by Dorothea von Mucke of Kittler's Introduction was first published in October 41 (1987): 101-18. The decision to produce our own version does not imply any criticism of the October translation (which was of great help to us) but merely reflects our decision to bring the Introduction in line with the bulk of the book to produce a stylisti cally coherent text. All translations of the primary texts interpolated by Kittler are our own, with the exception of the following: Rilke, "Primal Sound," has been reprinted from Rainer Maria Rilke, Selected Works, vol. I, Prose, trans. G. Craig Houston (New York: New Directions, 1961), 51-56. © 1961 by New Directions Publishing Corporation; used with permis sion. The translation of Heidegger's lecture on the typewriter originally appeared in Martin Heidegger, Parmenides, trans. Andre Schuwer and Richard Rojcewicz (Bloomington: Indiana Univ. Press, 1992), 80-81, 85-8 6. We would like to acknowledge the help we have received from June K. -
Rendering Ghost Ships and Other Phenomena in Arctic Atmospheres
Rendering Ghost Ships and Other Phenomena in Arctic Atmospheres Diego Gutierrez Francisco J. Seron Adolfo Muñoz Oscar Anson Grupo de Informática Gráfica Avanzada (GIGA), Universidad de Zaragoza Instituto de Investigación en Ingeniería de Aragón María de Luna 1, Edificio Ada Byron 50018, Zaragoza, Spain {diegog|seron|orbananos|[email protected]} ABSTRACT The unique characteristics of the arctic atmosphere make for very interesting effects that cannot be seen anywhere else in the planet. The extremely cold temperatures, along with the existence of inversion layers in the temperature gradients, make the medium highly inhomogeneous. Its properties, including the index of refraction that rules the behavior of light, are no longer constant. As a consequence, light rays get bent while traversing the atmosphere, and the result is some spectacular phenomena; several examples are the arctic mirages (that have probably given rise to numerous ghost ship legends), the Fata Morgana or the Novaya-Zemlya effect. We present here an implementation of a ray tracer that can render all these effects, thus depicting phenomena never ray-traced before, as far as the authors know. We first build an accurate temperature profile for the arctic atmosphere, based on experimental data, then calculate the curved paths of the light rays as the index of refraction changes as a function of temperature, by solving the physically-based differential equation that describes their trajectory. The scenes are modelled using real data for the Earth and Sun dimensions and relative distance, thus maintaining accuracy in the results obtained. Keywords Curved ray tracing, inhomogeneous media, arctic atmosphere 1. INTRODUCTION atmosphere, along with a physically-based resolution Refraction of sunlight due to cold dense polar air method that allows us to bend light correctly. -
Morgan Le Fay
Morgan Le Fay by Susa Morgan Black , FSA Scot. Medieval Story The contemporary stories of Morgan le Fay are based on Christianized versions found in the Medieval writings of the Vulgate and Malory. She is depicted as an evil and lusty enchantress who tricks her brother, good King Arthur, into an incestuous relationship with her, resulting in the unnatural birth of their son, Mordred. She tricks Arthur’s wizard, Merlin, into divulging his magical secrets to her, then disposes of him inside the trunk of a tree, or a crystal cave. She sows the seeds of discontent with gossip against Lancelot and Queen Guinevere, steals the magical sword, Excalibur with it’s healing scabbard, plots the death of Arthur with her various lovers, and ultimately contributes to the dissolution of the Round Table. Yet, even in this version, Morgan was one of the three queens that retrieved Arthur’s fatally wounded body from the Battle of Camlan on Salisbury Plain, and returned with him to the holy Isle of Avalon to heal him, for he is the Once and Future King, destined to return from the timeless fairy island when Britain is in need of him. Marian Zimmer Bradley rescues Morgan le Fay from the Medieval sources, and tells the story from Morgan’s own point of view, as recently seen in the excellent movie, The Mists of Avalon, based on her novel. Celtic Story Morgan was a Celtic Queen. One of the definitions of the name Morgan is “Great Queen” (Mohr Righan), which may have been an ancient royal title. -
William Scoresby, Jr. (1789-1857) and the Open Polar Sea - Myth and Reality CONSTANCE MARTIN’
ARCTIC VOL. 41. NO. 1 (MARCH 1988) P. 39-47 William Scoresby, Jr. (1789-1857) and the Open Polar Sea - Myth and Reality CONSTANCE MARTIN’ (Received 14 May 1987; acceptedin revised form 31 August 1987) ABSTRACT. WilliamScoresby, Jr., whaler and eminent naturalscientist, was denieda role in the BritishGovernment’s renewal ofpolar explorationin 1818. Befriended by Sir Joseph Banks anda member of the most respected leamed societies in Scotland, England and the Continent, Scoresby made detailed observationsof ice conditions in the Arcticover a period of 17years, aiding the government’s decisionto search for new polar routes. However, Scoresby and Sir John Barrow, Second Secretaryof the Admiralty, the main organizer of arcticexploration, had opposing perceptionsof thenature of the northern regions. Barrow, until the end of his life, believed the polar regions harbored a warm water sea, while Scoresby considered the theory a ludicrous chimera. This is believedto be the source of Barrow’s illogical rejectionof Scoresby. To support thisthesis the author has contrastedScoresby’s two major works,An Account of the Arctic Regions and Voyage tothe Whale Fishery, with Barrow’sarctic writings, A Chronological Historyof Voyages into the Arctic Regions and Voyage in the Arctic Regions from 1818 to the Present Time, as well as looking at other literary visions of the Arctic contemporary to the period. Scoresby’s ability as a mariner, his years of arcticexperience, his scientific education at the University of Edinburgh, his meticulous records and acute andsensitive observations in both prose and drawing, all provide a sound basis for perceiving the Admiralty’s autocratic rejection of Scoresby asa loss to arctic science in the 19thcentury.