An Artist's Revelation in a Walking Canvas 3 Tale of Ansel Adams
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Planetary Surfaces
Chapter 4 PLANETARY SURFACES 4.1 The Absence of Bedrock A striking and obvious observation is that at full Moon, the lunar surface is bright from limb to limb, with only limited darkening toward the edges. Since this effect is not consistent with the intensity of light reflected from a smooth sphere, pre-Apollo observers concluded that the upper surface was porous on a centimeter scale and had the properties of dust. The thickness of the dust layer was a critical question for landing on the surface. The general view was that a layer a few meters thick of rubble and dust from the meteorite bombardment covered the surface. Alternative views called for kilometer thicknesses of fine dust, filling the maria. The unmanned missions, notably Surveyor, resolved questions about the nature and bearing strength of the surface. However, a somewhat surprising feature of the lunar surface was the completeness of the mantle or blanket of debris. Bedrock exposures are extremely rare, the occurrence in the wall of Hadley Rille (Fig. 6.6) being the only one which was observed closely during the Apollo missions. Fragments of rock excavated during meteorite impact are, of course, common, and provided both samples and evidence of co,mpetent rock layers at shallow levels in the mare basins. Freshly exposed surface material (e.g., bright rays from craters such as Tycho) darken with time due mainly to the production of glass during micro- meteorite impacts. Since some magnetic anomalies correlate with unusually bright regions, the solar wind bombardment (which is strongly deflected by the magnetic anomalies) may also be responsible for darkening the surface [I]. -
Portrait of a Dramatic Stellar Crib 21 December 2006
Portrait of a dramatic stellar crib 21 December 2006 most massive stars known. The nebula owes its name to the arrangement of its brightest patches of nebulosity, that somewhat resemble the legs of a spider. They extend from a central 'body' where a cluster of hot stars (designated 'R136') illuminates and shapes the nebula. This name, of the biggest spiders on the Earth, is also very fitting in view of the gigantic proportions of the celestial nebula - it measures nearly 1,000 light-years across and extends over more than one third of a degree: almost, but not quite, the size of the full Moon. If it were in our own Galaxy, at the distance of another stellar nursery, the Orion Nebula (1,500 light-years away), it would cover one quarter of the sky and even be visible in daylight. One square degree image of the Tarantula Nebula and its surroundings. The spidery nebula is seen in the upper- center of the image. Slightly to the lower-right, a web of filaments harbors the famous supernova SN 1987A (see below). Many other reddish nebulae are visible in the image, as well as a cluster of young stars on the left, known as NGC 2100. Credit: ESO Known as the Tarantula Nebula for its spidery appearance, the 30 Doradus complex is a monstrous stellar factory. It is the largest emission nebula in the sky, and can be seen far down in the southern sky at a distance of about 170,000 light- years, in the southern constellation Dorado (The Swordfish or the Goldfish). -
The Problem of the Brisbane Tuff
50 VoL. XLV., No. 11. The Problem of the Brisbane Tuff. By PROFESSOR H. C. RICHARDS, D. Sc., and W. H. BRYAN, D. Sc. (Department of Geology, University of Queensland). PLATES IV.-VI. ( Accepted for publication by the Roya� Society of Qiu!ensland, 30th November, 1933). · 1. INTRODUCTION. The following paper recor�s an attempt to discover the ongm, and explain the mode of formation of the rock now known as the Brisbane Tuff. While the authors long ago realised that this rock possessed a number of unusual features, their doubts as to its true nature were revived and strengthened when a section showing well developed columnar structure was exposed in the municipal quarry at Windsor some three miles north of the centre of the city of Brisbane. A more detailed examination disclosed other anomalous features, but a search of the literature showed that the characters displayed by the Brisbane Tuff, although rare, were not unique but could be closely paralleled in the "Great Hot Sand Flow" of Alaska and in the "Ignimbrites " of New Zealand, while they also resembled in certain respects the " Nitees ardentes" of Mt. Pelee. In the pages which follow only those features that have a direct bearing on the origin and nature of the Eris bane Tuff will be con sidered. For a more general account the reader is referred. to the paper by Mrs. C. Briggs (1928) published in these proceedings. 2. EARLIER VIEWS AS TO ORIGIN AND MODE OF FORMATION. The rock which is now knpwn as the Eris bane Tuff was first described by Leichhardt (1855) who examined the rock on his visit to Brisbane in 1844. -
Testing Hypotheses for the Origin of Steep Slope of Lunar Size-Frequency Distribution for Small Craters
CORE Metadata, citation and similar papers at core.ac.uk Provided by Springer - Publisher Connector Earth Planets Space, 55, 39–51, 2003 Testing hypotheses for the origin of steep slope of lunar size-frequency distribution for small craters Noriyuki Namiki1 and Chikatoshi Honda2 1Department of Earth and Planetary Sciences, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581, Japan 2The Institute of Space and Astronautical Science, Yoshinodai 3-1-1, Sagamihara 229-8510, Japan (Received June 13, 2001; Revised June 24, 2002; Accepted January 6, 2003) The crater size-frequency distribution of lunar maria is characterized by the change in slope of the population between 0.3 and 4 km in crater diameter. The origin of the steep segment in the distribution is not well understood. Nonetheless, craters smaller than a few km in diameter are widely used to estimate the crater retention age for areas so small that the number of larger craters is statistically insufficient. Future missions to the moon, which will obtain high resolution images, will provide a new, large data set of small craters. Thus it is important to review current hypotheses for their distributions before future missions are launched. We examine previous and new arguments and data bearing on the admixture of endogenic and secondary craters, horizontal heterogeneity of the substratum, and the size-frequency distribution of the primary production function. The endogenic crater and heterogeneous substratum hypotheses are seen to have little evidence in their favor, and can be eliminated. The primary production hypothesis fails to explain a wide variation of the size-frequency distribution of Apollo panoramic photographs. -
Proceedings Geological Society of London
Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on February 18, 2016 PROCEEDINGS OF THE GEOLOGICAL SOCIETY OF LONDON. SESSION 1884-851 November 5, 1884. Prof. T. G. Bo~sEY, D.Sc., LL.D., F.R.S., President, in the Chair. William Lower Carter, Esq., B.A., Emmanuel College, Cambridge, was elected a Fellow of the Society. The SECRETARYaunouneed.bhat a water-colour picture of the Hot Springs of Gardiner's River, Yellowstone Park, Wyoming Territory, U.S.A., which was painted on the spot by Thomas Moran, Esq., had been presented to the Society by the artist and A. G. Re"::~aw, Esq., F.G.S. The List of Donations to the Library was read. The following communications were read :-- 1. "On a new Deposit of Pliocene Age at St. Erth, 15 miles east of the Land's End, Cornwall." By S. V. Wood, Esq., F.G.S. 2. "The Cretaceous Beds at Black Ven, near Lyme Regis, with some supplementary remarks on the Blackdown Beds." By the Rev. W. Downes, B.A., F.G.S. 3. "On some Recent Discoveries in the Submerged Forest of Torbay." By D. Pidgeon, Esq., F.G.S. The following specimens were exhibited :- Specimens exhibited by Searles V. Wood, Esq., the Rev. W. Downes, B.A., and D. Pidgeon, Esq., in illustration of their papers. a Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on February 18, 2016 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. A worked Flint from the Gravel-beds (? Pleistocene) in the Valley of the Tomb of the Kings, near Luxor (Thebes), Egypt, ex- hibited by John E. -
Remerciements – Unité 1
TVO ILC SNC1D Remerciements Remerciements – Unité 1 Graphs, diagrams, illustrations, images in this course, unless otherwise specified, are ILC created, Copyright © 2018 The Ontario Educational Communications Authority. All rights reserved. Intro Video, Copyright © 2018 The Ontario Educational Communications Authority. All rights reserved. All title artwork and graphics, unless otherwise specified, Copyright © 2018The Ontario Educational Communications Authority. All rights reserved. Logo: Science Presse , Agence Science-Presse, URL: https://www.sciencepresse.qc.ca/, Accessed 14/01/2019. Logo: Curium, Curium, URL: https://curiummag.com/wp-content/uploads/2017/10/logo_ curium-web.png, Accessed 14/01/2019. Logo: Science Étonnante, David Louapre, URL: https://sciencetonnante.wordpress.com/, Accessed 20/03/2018, © 2018 HowStuffWorks, a division of InfoSpace Holdings LLC, a System1 Company. Blog, blogging and blogglers theme, djvstock/iStock/Getty Images Logo: Wordpress, WordPress.com, Automattic Inc., URL: https://wordpress.com/, Accessed 20/03/2018, © The WordPress Foundation. Logo: Wix, Wix.com, Inc., URL: https://static.wixstatic.com/ media/9ab0d1_39d56f21398048df8af89aab0cec67b8~mv1.png, Accessed 14/01/2019. Logo: Blogger, Blogger, Inc., ZyMOS, URL: https://commons.wikimedia.org/wiki/File:Blogger. svg, Accessed 20/03/2018, © Google LLC. HOME A film by Yann Arthus-Bertrand, GoodPlanet Foundation, Europacorp and Elzévir Films, URL: https://www.youtube.com/watch?v=GItD10Joaa0, Published 04/02/2009, Accessed 20/04/2018, Courtesy of the GoodPlanet -
Compositional and Mineralogical Characteristics of Archimedes Crater Region Using Chandrayaan – 1 M3 Data
50th Lunar and Planetary Science Conference 2019 (LPI Contrib. No. 2132) 1040.pdf COMPOSITIONAL AND MINERALOGICAL CHARACTERISTICS OF ARCHIMEDES CRATER REGION USING CHANDRAYAAN – 1 M3 DATA. P. R. Kumaresan1 and J. Saravanavel2, 1Research Scholar, 2Assistant Professor, Department of Remote Sensing, Bharathidasan University, Tiruchirappalli-23, Tamil Nadu, India, email: [email protected], [email protected] Introduction: The Earth’s natural satellite the tometry corrected reflectance data captured during the moon is nearest celestial body appears brightest object OP1B optical period. in our night sky. Moon surfaces are composed of dark and light areas. The dark areas are called Maria which is made up of basaltic terrain and light areas are high- lands mostly made up of Anorthositic rocks. The moon surface is littered with craters, which are formed when meteors hit its surface. To understand the evolution, geological process of the moon it is important to study the surface composition and minerals present in crustal surface. In this regard, in our study, we have attempted to map the minerals and surface composition of Archi- medes crater region. Study area: Archimedes crater is a large impact crater located on the eastern edges of the Mare Imbri- um of near side moon (29.7° N, 4.0° W). The diameter of the crater is 83 km with smooth floor flooded (1) with mare basalt and lack of a central peak. The rim (2) has a significant outer rampart brightened with ejecta (3) and the some portion of a terraced inner wall. Ar- chimedes Crater is named for the Greek mathematician Archimedes, who made many mathematical discoveries in the 200 B.C [1, 2]. -
The Moon After Apollo
ICARUS 25, 495-537 (1975) The Moon after Apollo PAROUK EL-BAZ National Air and Space Museum, Smithsonian Institution, Washington, D.G- 20560 Received September 17, 1974 The Apollo missions have gradually increased our knowledge of the Moon's chemistry, age, and mode of formation of its surface features and materials. Apollo 11 and 12 landings proved that mare materials are volcanic rocks that were derived from deep-seated basaltic melts about 3.7 and 3.2 billion years ago, respec- tively. Later missions provided additional information on lunar mare basalts as well as the older, anorthositic, highland rocks. Data on the chemical make-up of returned samples were extended to larger areas of the Moon by orbiting geo- chemical experiments. These have also mapped inhomogeneities in lunar surface chemistry, including radioactive anomalies on both the near and far sides. Lunar samples and photographs indicate that the moon is a well-preserved museum of ancient impact scars. The crust of the Moon, which was formed about 4.6 billion years ago, was subjected to intensive metamorphism by large impacts. Although bombardment continues to the present day, the rate and size of impact- ing bodies were much greater in the first 0.7 billion years of the Moon's history. The last of the large, circular, multiringed basins occurred about 3.9 billion years ago. These basins, many of which show positive gravity anomalies (mascons), were flooded by volcanic basalts during a period of at least 600 million years. In addition to filling the circular basins, more so on the near side than on the far side, the basalts also covered lowlands and circum-basin troughs. -
Water on the Moon, III. Volatiles & Activity
Water on The Moon, III. Volatiles & Activity Arlin Crotts (Columbia University) For centuries some scientists have argued that there is activity on the Moon (or water, as recounted in Parts I & II), while others have thought the Moon is simply a dead, inactive world. [1] The question comes in several forms: is there a detectable atmosphere? Does the surface of the Moon change? What causes interior seismic activity? From a more modern viewpoint, we now know that as much carbon monoxide as water was excavated during the LCROSS impact, as detailed in Part I, and a comparable amount of other volatiles were found. At one time the Moon outgassed prodigious amounts of water and hydrogen in volcanic fire fountains, but released similar amounts of volatile sulfur (or SO2), and presumably large amounts of carbon dioxide or monoxide, if theory is to be believed. So water on the Moon is associated with other gases. Astronomers have agreed for centuries that there is no firm evidence for “weather” on the Moon visible from Earth, and little evidence of thick atmosphere. [2] How would one detect the Moon’s atmosphere from Earth? An obvious means is atmospheric refraction. As you watch the Sun set, its image is displaced by Earth’s atmospheric refraction at the horizon from the position it would have if there were no atmosphere, by roughly 0.6 degree (a bit more than the Sun’s angular diameter). On the Moon, any atmosphere would cause an analogous effect for a star passing behind the Moon during an occultation (multiplied by two since the light travels both into and out of the lunar atmosphere). -
GRAIL Reveals Secrets of the Lunar Interior
GRAIL Reveals Secrets of the Lunar Interior — Dr. Patrick J. McGovern, Lunar and Planetary Institute A mini-flotilla of spacecraft sent to the Moon in the past few years by several nations has revealed much about the characteristics of the lunar surface via techniques such as imaging, spectroscopy, and laser ranging. While the achievements of these missions have been impressive, only GRAIL has seen deeply enough to reveal inner secrets that the Moon holds. LRecent Lunar Missions Country Name Launch Date Status ESA Small Missions for Advanced September 27, 2003 Ended with lunar surface impact on Research in Technology-1 (SMART-1) September 3, 2006 USA Acceleration, Reconnection, February 27, 2007 Extension of the THEMIS mission; ended Turbulence and Electrodynamics of in 2012 the Moon’s Interaction with the Sun (ARTEMIS) Japan SELENE (Kaguya) September 14, 2007 Ended with lunar surface impact on June 10, 2009 PChina Chang’e-1 October 24, 2007 Taken out of orbit on March 1, 2009 India Chandrayaan-1 October 22, 2008 Two-year mission; ended after 315 days due to malfunction and loss of contact USA Lunar Reconnaissance Orbiter (LRO) June 18, 2009 Completed one-year primary mission; now in five-year extended mission USA Lunar Crater Observation and June 18, 2009 Ended with lunar surface impact on Sensing Satellite (LCROSS) October 9, 2009 China Chang’e-2 October 1, 2010 Primary mission lasted for six months; extended mission completed flyby of asteroid 4179 Toutatis in December 2012 USA Gravity Recovery and Interior September 10, 2011 Ended with lunar surface impact on I Laboratory (GRAIL) December 17, 2012 To probe deeper, NASA launched the Gravity Recovery and Interior Laboratory (GRAIL) mission: twin spacecraft (named “Ebb” and “Flow” by elementary school students from Montana) flying in formation over the lunar surface, tracking each other to within a sensitivity of 50 nanometers per second, or one- twenty-thousandth of the velocity that a snail moves [1], according to GRAIL Principal Investigator Maria Zuber of the Massachusetts Institute of Technology. -
Appendix I Lunar and Martian Nomenclature
APPENDIX I LUNAR AND MARTIAN NOMENCLATURE LUNAR AND MARTIAN NOMENCLATURE A large number of names of craters and other features on the Moon and Mars, were accepted by the IAU General Assemblies X (Moscow, 1958), XI (Berkeley, 1961), XII (Hamburg, 1964), XIV (Brighton, 1970), and XV (Sydney, 1973). The names were suggested by the appropriate IAU Commissions (16 and 17). In particular the Lunar names accepted at the XIVth and XVth General Assemblies were recommended by the 'Working Group on Lunar Nomenclature' under the Chairmanship of Dr D. H. Menzel. The Martian names were suggested by the 'Working Group on Martian Nomenclature' under the Chairmanship of Dr G. de Vaucouleurs. At the XVth General Assembly a new 'Working Group on Planetary System Nomenclature' was formed (Chairman: Dr P. M. Millman) comprising various Task Groups, one for each particular subject. For further references see: [AU Trans. X, 259-263, 1960; XIB, 236-238, 1962; Xlffi, 203-204, 1966; xnffi, 99-105, 1968; XIVB, 63, 129, 139, 1971; Space Sci. Rev. 12, 136-186, 1971. Because at the recent General Assemblies some small changes, or corrections, were made, the complete list of Lunar and Martian Topographic Features is published here. Table 1 Lunar Craters Abbe 58S,174E Balboa 19N,83W Abbot 6N,55E Baldet 54S, 151W Abel 34S,85E Balmer 20S,70E Abul Wafa 2N,ll7E Banachiewicz 5N,80E Adams 32S,69E Banting 26N,16E Aitken 17S,173E Barbier 248, 158E AI-Biruni 18N,93E Barnard 30S,86E Alden 24S, lllE Barringer 29S,151W Aldrin I.4N,22.1E Bartels 24N,90W Alekhin 68S,131W Becquerei -
Autonomous Quantum Heat Engine Using an Electron Shuttle
Autonomous quantum heat engine using an electron shuttle Behnam Tonekaboni,1, 2, ∗ Brendon W. Lovett,3 and Thomas M. Stace1, 2 1School of Mathematics and Physics, University of Queensland, Brisbane, QLD, 4072, Australia 2ARC Centre for Engineered Quantum Systems, The University of Queensland, Brisbane, QLD 4072, Australia 3SUPA, School of Physics and Astronomy, University of St Andrews, St. Andrews KY16 9SS, United Kingdom We propose an autonomous quantum heat engine based on the thermally driven oscillation of a single electron shuttle. The electronic degree of freedom of this device acts as an internal dynamical controller which switches the interaction of the engine with the thermal baths. We show that in addition to energy flux through the thermal baths, a flux of energy is attributed to the controller and it affects the engine power. I. INTRODUCTION autonomous system. An autonomous rotor engine was proposed [9] inspired by classical rotor engine where the With the advancement in experimental techniques, we state of the rotor determines the interactions and is con- are able to build and control devices with truly quantum sidered as the internal clock. Neither of these papers degrees of freedom. In these quantum devices, the ener- address the energetic cost of the controller or the clock. getics and thermodynamics of the control field become To fully account for the energetic cost of the controller, important. Thermodynamics of such quantum devices we develop a model of an autonomous engine, by replac- have been studied in the context of quantum heat en- ing the external control field with an internal dynami- gines and fridges [1{3], driven nano-systems [4], effect of cal quantum controller that switches the interactions be- energy transfer on quantum coherence [5,6] and many tween the engine and the baths [10].