DOCSLIB.ORG

THE ENTRANCE of MODERN OPTICS to OTTOMAN SCIENCE by Sena Pekkendir B.S., Physics, Boğaziçi University, 2011 Submitted To

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
THE ENTRANCE of MODERN OPTICS to OTTOMAN SCIENCE by Sena Pekkendir B.S., Physics, Boğaziçi University, 2011 Submitted To THE ENTRANCE OF MODERN OPTICS TO OTTOMAN SCIENCE by Sena Pekkendir B.S., Physics, Boğaziçi University, 2011 Submitted to the Institute for Graduate Studies in Science and Engineeering in partial fulfillment of the requirements for the degree of Master of Science Graduate Program in Physics Boğaziçi University 2015 ii THE ENTRANCE OF MODERN OPTICS TO OTTOMAN SCIENCE APPROVED BY: Prof. Levent Kurnaz ………………………... (Thesis Supervisor) Prof. İhsan Fazlıoğlu ………………………… (Thesis Co-advisor) Assoc. Prof. Burçin Ünlü ………………………… Prof. Edhem Eldem ………………………… Prof. Naci İnci ………………………… DATE OF APPROVAL: 02.07.2015 iii Dedicated to my husband Behiç and my son Ömer Melih iv ACKNOWLEDGEMENTS First of all, I’d like to express my sincere gratitude to my thesis advisor Prof. Levent Kurnaz for teaching me how to do academic research at first by joining me to his Soft Condensed Matter Lab when I was a sophomore. Also I’m very lucky to have been attended to his lectures on History of Science for that I discovered the branch I want to spend my life with. I’m so thankful to him to encourage and support me to write a thesis on history of science. I’d like to express my gratitude to Prof. İhsan Fazlıoğlu for always forcing me to be better and for teaching me a great deal of wisdom of academy. I’m very grateful for the things I’ve learned from him and I’m lucky that I’ll continue learning from him in the upcoming years. I also would like to thank my mother Sera Sarı for being there whenever I need her and always supporting me. I’d like to thank my sister Semanur for always being a good friend and a motivation. I’d like to thank my grandfather Mehmet Ali Sarı for teaching me Ottoman and giving me his time whenever I asked for it. I’d like to thank my mother in law Ayşe Şakire for the support she gives and my father in law Prof. Mehmet Akif Aydın for the encouraging academic environment he provides in our family. I’d like to thank my eight-month old son for the meaning he brought into my life, for always being a source of joy and for standing my absence in those times I’d been working instead of being with him. But mostly I’d like to thank my husband Behiç Aydın, for the love and attention he gives me, for our happy life together, for his endless support and encouragement. v ABSTRACT THE ENTRANCE OF MODERN OPTICS TO OTTOMAN SCIENCE In Ottoman State, modern sciences were brought into the country as a result of military targets. The first engineering schools were being established from the beginning of 18th century and foreigner scholars were brought in, to provide the transmission of knowledge. Also a comprehensive translation movement from the West was initiated. One of the pioneers of this movement, Chief Instructor of the Imperial School of Military Engineering, Ishak Efendi (d. 1836), wrote a treatise in Ottoman named Mecmua-i Ulum-i Riyaziye (Istanbul 1247-1250/1831-1834) using European resources. Mecmua-i Ulum-i Riyaziye is the first encyclopedia of positive sciences in Ottoman State and the first comprehensive study to represent positive sciences systematically. It’s also credited for its presentation of Western European optical knowledge to Ottoman science properly. This study aims to examine the process of the entrance of modern optics to Ottoman State. Firstly, it presents the development of the science of optics from the ancient ages to the 18th century in order to present the back ground of the modern optical thought. Then, it focuses on the innovations in Ottoman State and the process of the entrance of modern sciences into the country. It examines the chapters of Mecmua-i Ulum-i Riyaziye on optics in order to track down the transmission of optical knowledge from West to Ottoman State and it examines the literature of Optical Work provided by Ottoman scholars. The study concludes in 1937, when modern concepts of optics were introduced into the country by Refik Fenmen. vi ÖZET MODERN OPTİK BİLİMİNİN OSMANLI BİLİMİNE GİRİŞİ Osmanlı Devleti’nde modern bilimlerin ülkeye girişi askeri hedefler sonucu gerçekleşmiştir. 18. Yüzyılın başından itibaren ilk mühendishaneler kurulmaya başlamış ve yurtdışından hocalar getirilerek bilgi aktarımı sağlanmaya çalışılmıştır. Öte yandan, geniş kapsamlı bir çeviri haraketi başlatılmıştır. Bu çeviri hareketinin öncülerinden biri olan, Mühendishane-i Berri-i Hümayun Başhocası İshak Efendi (d. 1836), Avrupalı kaynaklardan faydalanarak Osmanlıca Mecmua-i Ulum-i Riyaziye (Istanbul 1247- 1250/1831-1834) isimli bir eser kaleme almıştır. Mecmua-i Ulum-i Riyaziye Osmanlı Devleti’ndeki ilk pozitif bilimler ansiklopedisi ve de pozitif bilimleri sistematik bir şekilde sunan ilk kapsamlı çalışmadır. Bu eser, öte yandan Batı Avrupa kaynaklarındaki optik bilgileri Osmanlı Bilimine düzgün bir şekilde sunuyor olmasından ötürü itibar kazanmıştır. Bu çalışma modern optik biliminin Osmanlı Bilimine giriş sürecini incelemeyi amaçlamaktadır. Öncelikle, optik biliminin antik çağdan 18. Yüzyıla seyreden gelişimi sunularak modern optik düşüncenin arka planının sergilenmesi hedeflenmiştir. Sonra, Osmanlı Devleti’nde gerçekleşen yeniliklere ve modern bilimlerin ülkeye giriş sürecine odaklanılmaktadır. Optik bilgilerin Batı’dan Osmanlı’ya aktarım sürecinin izini sürmek için Mecmua-i Ulum-i Riyaziye’nin optik bilimine dair olan bölümleri ve Osmanlı Bilim İnsanlarının oluşturduğu optik literatürü incelenmektedir. Çalışma, modern optik kavramklarının Refik Fenmen tarafından ülkeye takdim edildiği 1937 yılında son bulmaktadır. vii TABLE OF CONTENTS ACKNOWLEDGEMENTS .................................................................................................. iv ABSTRACT ........................................................................................................................... v ÖZET .................................................................................................................................... vi LIST OF FIGURES ……………………………………………………………………………… x LIST OF TABLES ……………………………………………………………………………... xii LIST OF ACRONYMS/ABBREVIATIONS……...………………………………………... xiii 1. INTRODUCTION ............................................................................................................ 1 1.1. The Emergence of the Science of Optics in Ancient Greece ................................... 3 1.1.1. Early History of Optics ................................................................................ 3 1.1.2. Theories on Direct Vision ............................................................................ 4 1.1.2.1. Intromission Theory………………………………………………….4 1.1.2.2. Extramission Theory………………………………………………..5 1.1.2.3. Mediumistic Theory…………………………………………………6 1.1.3. Geometrical Interpretation of Direct Vision ................................................ 7 1.1.4. Geometrical Interpretation of Reflection ..................................................... 9 1.1.5. Geometrical Interpretation of Refraction .................................................. 10 1.2. Transfer of the Science of Optics into Medieval Islam ......................................... 11 1.2.1. The Translation Movement from Greek to Arabic ..................................... 11 1.2.2. Theories on Direct Vision .......................................................................... 12 1.2.2.1. Extramission Theory………………………………………………13 1.2.2.2. Intromission Theory……………………………………………….16 2. ALHAZEN AND HIS SCHOOL OF OPTICS .............................................................. 20 2.1. Alhazen as the Father of Modern Optics ............................................................... 20 2.1.1. Theories on Direct Vision .......................................................................... 22 2.1.1.1. The New Intromission Theory…………………………………… 22 2.1.2. Theories on Reflection ............................................................................... 24 2.1.3. Theories on Refraction ............................................................................... 25 2.1.4. The Influence of Alhazen in the West ........................................................ 25 viii 2.2. The School of Alhazen .......................................................................................... 27 2.2.1. Theories on Direct Vision .......................................................................... 27 2.2.2. Theories on Reflection ............................................................................... 28 2.2.3. Theories on Refraction ............................................................................... 28 2.3. Optics in the Ottoman Science during the Classical Period ................................... 29 2.3.1. Theories on Direct Vision .......................................................................... 31 2.3.2. Theories on Reflection ............................................................................... 33 2.3.3. Theories on Refraction ............................................................................... 33 3. THE DEVELOPMENT OF MODERN OPTICS .......................................................... 35 3.1. Optics in Medieval Europe .................................................................................... 35 3.1.1. Theories on Direct Vision .......................................................................... 35 3.1.2. Theories on Reflection and Refraction ....................................................... 37 3.2. The Development of Modern Optics ...................................................................... 39 3.2.1. Theories on Direct Vision .........................................................................
Load more

Recommended publications
  • Improving Point Cloud Quality for Mobile Laser Scanning
    School of Engineering and Science Dissertation for a Ph.D. in Computer Science Improving Point Cloud Quality for Mobile Laser Scanning Jan Elseberg November 2013 Supervisor: Prof. Dr. Andreas Nüchter Second Reviewer: Prof. Dr. Andreas Birk Third Reviewer: Prof. Dr. Joachim Hertzberg Fourth Reviewer: Prof. Dr. Rolf Lakämper Date of Defense: 13th of September 2013 Abstract This thesis deals with mobile laser scanning and the complex challenges that it poses to data processing, calibration and registration. New approaches to storing, searching and displaying point cloud data as well as algorithms for calibrating mobile laser scanners and registering laser scans are presented and discussed. Novel methods are tested on state of the art mobile laser scanning systems and are examined in detail. Irma3D, an autonomous mobile laser scanning platform has been developed for the purpose of experimentation. This work is the result of several years of research in robotics and laser scanning. It is the accumulation of many journal articles and conference papers that have been reviewed by peers in the field of computer science, robotics, artificial intelligence and surveying. Danksagung The work that goes into finishing a work like this is long and arduous, yet it can at times be pleasing, exciting and even fun. I would like to thank my advisor Prof. Dr. Andreas Nüchter for providing such joy during my experiences as a Ph.D. student. His infectious eagerness for the subject and his ability to teach are without equal. Prof. Dr. Joachim Hertzberg deserves many thanks for introducing me to robotics and for being such an insightful teacher of interesting subjects.
    [Show full text]
  • UC San Diego UC San Diego Electronic Theses and Dissertations
    UC San Diego UC San Diego Electronic Theses and Dissertations Title The science of the stars in Danzig from Rheticus to Hevelius / Permalink https://escholarship.org/uc/item/7n41x7fd Author Jensen, Derek Publication Date 2006 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, SAN DIEGO THE SCIENCE OF THE STARS IN DANZIG FROM RHETICUS TO HEVELIUS A dissertation submitted in partial satisfaction of the requirements for the degree Doctor of Philosophy in History (Science Studies) by Derek Jensen Committee in charge: Professor Robert S. Westman, Chair Professor Luce Giard Professor John Marino Professor Naomi Oreskes Professor Donald Rutherford 2006 The dissertation of Derek Jensen is approved, and it is acceptable in quality and form for publication on microfilm: _________________________________________ _________________________________________ _________________________________________ _________________________________________ _________________________________________ Chair University of California, San Diego 2006 iii FOR SARA iv TABLE OF CONTENTS Signature Page........................................................................................................... iii Dedication ................................................................................................................. iv Table of Contents ...................................................................................................... v List of Figures ..........................................................................................................
    [Show full text]
  • Investigating Gifted Middle School Students' Images About
    Science Education International Vol. 27, Issue 1, 2016, 136-150 Investigating Gifted Middle School Students’ Images about Scientists: A Cultural Similarity Perspective N. BAYRI*, M. S. KOKSAL†, P. ERTEKIN‡ ABSTRACT: The purpose of this study is to investigate gifted middle school students’ images about scientists in terms of cultural similarity. Sample of the study is 64 gifted middle school students taking courses from a formal school for gifted students. The data were collected by using Draw-a-scientist (DAST) instrument and was analysed by two researchers using Draw-a-scientist C form. The data involved two different drawings for the scientist from similar culture and the popular scientists respectively, and explanations of the drawings. When looked at the findings from cultural similarity perspective, it was seen that the findings about the drawings changed for the scientists in terms of cultural similarity with the students. They wrote mostly Einstein and Edison for the popular scientists while they gave names of Cahit Arf, Avicenna and Ali Qushji for scientists from similar culture. Also they did draw lab coat and eyeglasses more frequently for the popular scientists than those for scientists from similar culture. As another finding, they drew more number of tools for research of common scientists than those for scientists from similar culture. Finally, they drew messy, noisy, non-sterile places for the scientists from similar culture while they imagined the scientists from similar culture as lazy, ignorant inattentive and clumsy. These findings show importance of cultural similarity perception of gifted students on the scientists when they think about the scientists, this situation asks new questions about culture-dependent scientist images of gifted students to gifted science education researchers using DAST.
    [Show full text]
  • Hadley's Octant (A. D. 1731)
    HADLEY’S OCTANT (A. D. 1731). On the occasion of the second centenary of the invention of reflecting instruments and in accordance with the usual custom of reproducing in the Hydrographic Review documents of particular interest connected with the history of nautical and hydrographic science, the communication made by John Hadley to the Royal Society of London on 13th May, 1731, is repro­ duced hereafter in facsimile. This communication was published in N° 420 of the Philosophical Transactions. It appears that the oldest document in which allusion is made to the principle of reflection by plane mirrors, as applied to the measurement of angles, is the History of the Royal Society of London by B ir c h . In this book, under the date of 22nd August, 1666, it is stated “ Mr. H o o k mentionned a new astronomical instrument for making observations of distances by reflection”. In another place it may be read that on the 29th August of the same year, H o o k spoke of this instrument again, it being then under construction, to the members of the Society. They invited him to submit it as soon as possible and this was done on 12th September of that year. The instrument submitted by H o o k differed in important details from the modern sextant; it was provided with but one mirror and thus was a single reflecting instrument. This was the fundamental defect which made it impos­ sible for H o o k ’s invention to be a success. However, the idea of using reflection from a plane mirror for the measu­ rement of angles was not forgotten and, in spite of H o o k ’s want of success the principle was taken up by others who sought to correct the disadvantages of the instrument as first invented.
    [Show full text]
  • On Some Borrowed and Misunderstood Problems in Greek Catoptrics
    On Some Borrowed and Misunderstood Problems in Greek Catoptrics by ALEXANDERJONES Optics was one of the first sciences to which ancient Greek mathe- maticians attempted to apply the apparatus of geometry. They were most successful in describing geometrically certain phenomena of per- spective (as in Euclid’s Optics and parts of Pappus’s Collection, Book 6),less so in catoljtrics, the study of mirrors.’ The problems typically encountered in the surviving writings on catoptrics fall into two classes: those dealing with the reflection of rays cast from a luminous source such as the sun upon minors of plane or curved surface, and those involving the projection of lines of sight from the eye by way of a minor to an object. The most basic problem of the first class, to make a burning mirror, is solved correctly in Diocles’s On Burning Mirrors (ca. 200 B.C.) with both spherical and parabolic mirrors; other prob- lems were investigated by Diocles, by Anthemius (ca. A.D. 620) in his On Paradoxical Devices, and doubtless by other authors in the cen- turies between.2 In general these problems were amenable to geo- metrical treatment in antiquity because Hellenistic geometers were equipped to study the tangent lines to a wide range of curves (or the tangent planes to analogous surfaces) and the behaviour of straight lines in a given direction or through a given point .and inflected at the curve or surface at equal angles to the tangent at the point of in- cidence. Problems of the other class, in which it was required to make an ar- rangement of mirrors or a mirror with a special curvature, such that a *Institute for the History and Philosophy of Science and Technology, Victoria College, Univer- sity of Toronto, Toronto, Canada MSS 1K7.
    [Show full text]
  • Dramatis Personae •
    Dramatis Personae • Note: all dates are approximate. ALEXANDER THE GREAT (356– 323 bc). Macedonian ruler who, af- ter invading Central Asia in 329 bc, spent three years in the region, establishing or renaming nine cities and leaving behind the Bactrian Greek state, headquartered at Balkh, which eventually ruled territo- ries extending into India. Awhad al- Din ANVARI (1126– 1189). Poet and boon companion of Sultan Sanjar at Merv who, boasting of his vast knowledge, wrote that, “If you don’t believe me, come and test me. I am ready.” Nizami ARUDI. Twelfth- century Samarkand- born poet and courtier of the rulers of Khwarazm and of Ghor, and author of Four Discourses, in which he argued that a good ruler’s intellectual stable should include secretaries, poets, astrologers, and physicians. Abu Mansur Ali ASADI. Eleventh- century poet from Tus and follower of Ferdowsi. Working at a court in Azerbaijan, Asadi versified The Epic of Garshasp (Garshaspnameh), which ranks second only to Ferdowsi’s Shahnameh among Persian epic poems. Farid al- Din ATTAR (1145– 1221). Pharmacist and Sufi poet from Nishapur, who combined mysticism with the magic of the story- teller’s art. His Conference of the Birds is an allegory in which the birds of the world take wing in search of Truth, only to find it within themselves. Yusuf BALASAGUNI (Yusuf of Balasagun). Author in 1069 of the Wisdom of Royal Glory, a guide for rulers and an essay on ethics. Written in a Turkic dialect, Yusuf’s volume for the first time brought a Turkic language into the mainstream of Mediterranean civilization and thought.
    [Show full text]
  • Al-K¯Ash¯I's Mift¯Ah.Al-H.Isab, Volume I Arithmetic
    Al-K¯ash¯ı’sMift¯ah. Al-H. isab, Volume I Arithmetic: Translation and Commentary Nuh Aydin and Lakhdar Hammoudi Contents 1 Preface 3 2 Introduction5 2.1 A Biography of al-K¯ash¯ıand a Brief History..................5 2.2 List of al-K¯ash¯ı’sKnown Works......................... 10 2.3 Manuscript Copies of Mift¯ah. ........................... 14 2.4 Modern Researchers' Assessment of Mift¯ah. and al-K¯ash¯ı’sWork....... 16 2.5 Pedagogical Aspects of Mift¯ah. .......................... 18 2.6 Possible Future Projects............................. 20 2.7 Notes on Translation and the Purpose of This Work.............. 21 3 The Mift¯ah. Translation 22 3.1 Cover Page.................................... 22 3.2 Preface of The Mift¯ah. .............................. 24 3.3 Table of Content of The Mift¯ah. ......................... 30 3.4 The First Treatise on Integer Arithmetic.................... 41 3.5 The Second Treatise on Arithmetic of Fraction................. 123 3.6 The Third Treatise on Arithmetic of Astronomers............... 185 References 245 2 1 Preface It is unfortunate that one of the most important mathematics books of the medieval Islamic civilization,1 namely Mift¯ah. al-H. isab written by al-K¯ash¯ı in 1427, has not been fully trans- lated to English before. In fact, until the middle of the twentieth century it was unknown to modern researchers [27]. According to Rashed [31], traditional history of mathematics was shaken by Luckey's discovery of this monumental work. Mift¯ah. Al-H. isab is written in Arabic and has never been fully translated to another language except for Russian [33]. Also, two small sections of Mift¯ah.
    [Show full text]
  • Lunar Distances Final
    A (NOT SO) BRIEF HISTORY OF LUNAR DISTANCES: LUNAR LONGITUDE DETERMINATION AT SEA BEFORE THE CHRONOMETER Richard de Grijs Department of Physics and Astronomy, Macquarie University, Balaclava Road, Sydney, NSW 2109, Australia Email: [email protected] Abstract: Longitude determination at sea gained increasing commercial importance in the late Middle Ages, spawned by a commensurate increase in long-distance merchant shipping activity. Prior to the successful development of an accurate marine timepiece in the late-eighteenth century, marine navigators relied predominantly on the Moon for their time and longitude determinations. Lunar eclipses had been used for relative position determinations since Antiquity, but their rare occurrences precludes their routine use as reliable way markers. Measuring lunar distances, using the projected positions on the sky of the Moon and bright reference objects—the Sun or one or more bright stars—became the method of choice. It gained in profile and importance through the British Board of Longitude’s endorsement in 1765 of the establishment of a Nautical Almanac. Numerous ‘projectors’ jumped onto the bandwagon, leading to a proliferation of lunar ephemeris tables. Chronometers became both more affordable and more commonplace by the mid-nineteenth century, signaling the beginning of the end for the lunar distance method as a means to determine one’s longitude at sea. Keywords: lunar eclipses, lunar distance method, longitude determination, almanacs, ephemeris tables 1 THE MOON AS A RELIABLE GUIDE FOR NAVIGATION As European nations increasingly ventured beyond their home waters from the late Middle Ages onwards, developing the means to determine one’s position at sea, out of view of familiar shorelines, became an increasingly pressing problem.
    [Show full text]
  • Philosophical Paradigm of Islamic Cosmology
    Vol. 7(2), pp. 13-21, February, 2016 DOI:10.5897/PPR2015.0135 Article Number: E1A8ABA57874 ISSN:2141-663X Philosophical Papers and Reviews Copyright © 2016 Author(s) retain the copyright of this article http://www.academicjournals.org/PPR Review Philosophical paradigm of Islamic cosmology Ali Mohammad Bhat Islamic Research Academy, India. Received 5 October, 2015; Accepted 11 February, 2016 Humans have been examining the cosmic bodies for many millennia, but scientific discoveries and ideas about the origin of the universe have changed the religious discourse and rely completely on empiricism. Many theories were put forth by the physicists, philosophers and even religions at large but Islam has its prime source of information “Quran” upon which Muslim cosmologists builds their theories and directed their ideas about the cosmology. According to Quran with the role of man or other creatures in the formation and regulation of heavenly bodies, it is God who holds everything and has power to create things which are observable or hidden in this universe. A large portion of the Holy Quran contains such information from first big bang to expansion of the universe, the concept of time, space, creation of heavens and earth, constellations and extinction of the total canvas of the universe. An attempt has been made to answer all the challenges put forth by modern sciences to religious knowledge particularly to Islamic cosmology. Different sources were utilized to highlight those challenges and response to them is provided through mutakallimun literature, and also directly from Qur’anic references. Key words: Big-Bang, cosmology, cosmogony, expansion of universe, formation of sky and earth, Ratqan, red shift.
    [Show full text]
  • Ottoman Mathematicians and Astronomers
    Sino-US English Teaching, January 2018, Vol. 15, No. 1, 49-55 doi:10.17265/1539-8072/2018.01.008 D DAVID PUBLISHING Ottoman Mathematicians and Astronomers Malahat Abdullayeva Azerbaijan State Pedagogical University, Baku, Azerbaijan The article deals with the scientists in the Ottoman Empire. The readers will get interesting information about the life and practices of those who dedicated their whole life to the development of science, such as Ottoman mathematicians and astronomer Rumi Kadizade from Bursa, Ali Kushchu, Mirim Chalabi, Takiyuddin Bin Maruf-i, Gelenbevi Ismail Efendi, Hoca Ishak Efendi, and Huseyin Tevfik Pasha. Keywords: Ottoman Empire, mathematics, astronomy, observatory Introduction The history of science and education goes as far as the history of humanity. As in all historical periods, the fields of science and education rapidly developed during the Ottoman Empire. The reason for this development was thinkers and intelligent people of that time, the scientists who spent their lives to thinking, and intelligent people who spent their lives on scientific researches, studies, and innovations. At a time when missionaries who opened a school in the Ottoman lands tried to realize their mission, especially spread Christianity around the world, broad-minded and patriotic people of the time developed natural sciences, including mathematics, physics, chemistry, astronomy, and technical fields, but at the same time, they have achieved a high level of education by using new techniques. Just in this sense, it would be expedient to study the life and activity of the connoisseurs of science who lived and created works in the Ottoman Empire and whose scientific researches are used by use today.
    [Show full text]
  • Atmospheric Refraction: a History
    Atmospheric refraction: a history Waldemar H. Lehn and Siebren van der Werf We trace the history of atmospheric refraction from the ancient Greeks up to the time of Kepler. The concept that the atmosphere could refract light entered Western science in the second century B.C. Ptolemy, 300 years later, produced the first clearly defined atmospheric model, containing air of uniform density up to a sharp upper transition to the ether, at which the refraction occurred. Alhazen and Witelo transmitted his knowledge to medieval Europe. The first accurate measurements were made by Tycho Brahe in the 16th century. Finally, Kepler, who was aware of unusually strong refractions, used the Ptolemaic model to explain the first documented and recognized mirage (the Novaya Zemlya effect). © 2005 Optical Society of America OCIS codes: 000.2850, 010.4030. 1. Introduction the term catoptrics became reserved for reflection Atmospheric refraction, which is responsible for both only, and the term dioptrics was adopted to describe astronomical refraction and mirages, is a subject that the study of refraction.2 The latter name was still in is widely dispersed through the literature, with very use in Kepler’s time. few works dedicated entirely to its exposition. The same must be said for the history of refraction. Ele- ments of the history are scattered throughout numer- 2. Early Greek Theories ous references, many of which are obscure and not Aristotle (384–322 BC) was one of the first philoso- readily available. It is our objective to summarize in phers to write about vision. He considered that a one place the development of the concept of atmo- transparent medium such as air or water was essen- spheric refraction from Greek antiquity to the time of tial to transmit information to the eye, and that vi- Kepler, and its use to explain the first widely known sion in a vacuum would be impossible.
    [Show full text]
  • A Survey for Low-Mass Stellar and Substellar Members of the Hyades Open Cluster
    Astronomy & Astrophysics manuscript no. aa30134-16˙12Jan2018 © ESO 2018 January 16, 2018 A survey for low-mass stellar and substellar members of the Hyades open cluster. Stanislav Melnikov1;2 and Jochen Eislo¨ffel1 1 Thuringer¨ Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany 2 Ulugh Beg Astronomical Institute, Astronomical str. 33, 700052 Tashkent, Uzbekistan Received / Accepted ABSTRACT Context. Unlike young open clusters (with ages < 250 Myr), the Hyades cluster (age ∼ 600 Myr) has a clear deficit of very low-mass stars (VLM) and brown dwarfs (BD). Since this open cluster has a low stellar density and covers several tens of square degrees on the sky, extended surveys are required to improve the statistics of the VLM/BD objects in the cluster. Aims. We search for new VLM stars and BD candidates in the Hyades cluster to improve the present-day cluster mass function down to substellar masses. Methods. An imaging survey of the Hyades with a completeness limit of 21m: 5 in the R band and 20m: 5 in the I band was carried out with the 2k × 2k CCD Schmidt camera at the 2m Alfred Jensch Telescope in Tautenburg. We performed a photometric selection of the cluster member candidates by combining results of our survey with 2MASS JHKs photometry. Results. We present a photometric and proper motion survey covering 23.4 deg2 in the Hyades cluster core region. Using optical/IR colour-magnitude diagrams, we identify 66 photometric cluster member candidates in the magnitude range 14m: 7 < I < 20m: 5. The proper motion measurements are based on several all-sky surveys with an epoch difference of 60-70 years for the bright objects.
    [Show full text]