Working with light and shadows

2020 ◽  
Author(s):  
donatella giordano
Keyword(s):  
Angular Distance ◽  
Right To The City ◽  
The Sun ◽  
School Garden ◽  
Time Zone ◽  
The Earth ◽  
Exact Reproduction ◽  
Shadow It ◽  
The City ◽  
Opaque Body

<p>The observation of the behavior of sunlight when it encounters an opaque body and, consequently, the shadow it produces allows several considerations to be made.</p><p>First activity: In the school garden, pupils studied the apparent motion of the Sun by observing the movement of the shadow produced by a stick perpendicular to the ground. They drew on the ground the position of the shadow of the stick and measured every hour the angular distance between the different tracts. They verified that between one tract and the next there were always 15 degrees, which is the same angular distance between the meridians that make a time zone. Starting from this observation, the kids built a Sundial to determine the local time.</p><p>Second activity: Working with the Homothetic Globe, that is a globe freed from its support and inclined according to the parallel of the place where you are, and placing a toothpick right to the city on the Globe where you want to proceed with the observation, allows you to observe everything that happens regarding the behavior of light and shadows as an exact reproduction, in small, of what happens in reality: the Sun acts on the sphere/ world map, exactly the same way as on the sphere/ Earth. The students were able to observe how the Sun illuminates different regions of the Earth in real time, helping them to understand time zones. The Homothetic globe also allowed them to understand the alternation of seasons in our Planet.</p>

scholarly journals On a method of comparing the light of the Sun with that of the fixed stars

1833 ◽  
Vol 2 ◽  
pp. 355-355
Keyword(s):  
Full Moon ◽  
Angular Distance ◽  
The Other ◽  
The Sun ◽  
Proper Distance ◽  
The Earth ◽  
Direct Light ◽  
Glass Bulb ◽  
The Mean ◽  
Made In

In the Philosophical Transactions for the year 1767, a suggestion is thrown out by Mr. Michell, that a comparison between the light received from the sun and any of the fixed stars, might furnish data for estimating their relative distances; but no such direct comparison had been attempted. Dr. Wollaston was led to infer from some observations that he made in the year 1799, that the direct light of the sun is about one million times more intense than that of the full moon, and therefore very many million times greater than that of all the fixed stars taken collectively. In order to compare the light of the sun with that of a star, he took, as an intermediate object of comparison, the light of a candle reflected from a small bulb, about a quarter of an inch in diameter, filled with quicksilver, and seen, by one eye, through a lens of two inches focus, at the same time that the star or the sun’s image, placed at a proper distance, was viewed by the other eye through a telescope. The mean of various trials seemed to show that the light of Sirius is equal to that of the sun seen in a glass bulb one tenth of an inch in diameter, at the distance of 210 feet, or that they are in the proportion of one to ten thousand millions; but as nearly one half of the light is lost by reflection, the real proportion between the light from Sirius and the sun is not greater than that of one to twenty thousand millions. If the annual parallax of Sirius be half a second, corresponding to a distance of 525,481 times that of the sun from the earth, its diameter would be 3⋅7 times that of the sun, and its light 13⋅8 times as great. The distance at which the sun would require to be viewed, so that its brightness might be only equal to that of Sirius, would be 141,421 times its present distance; and if still in the ecliptic, its annual parallax in longitude would be nearly 3″; but if situated at the same angular distance from the ecliptic as Sirius is, it would have an annual parallax, in latitude, of 1″⋅8.

Seti Space Missions

1997 ◽  
Vol 161 ◽  
pp. 761-776 ◽  
Author(s):  
Claudio Maccone
Keyword(s):  
Electromagnetic Waves ◽  
Space Missions ◽  
Gravitational Lens ◽  
The Sun ◽  
Space Antenna ◽  
Focal Distance ◽  
Large Space ◽  
The Earth ◽  
Space Antennas ◽  
New Space

AbstractSETI from space is currently envisaged in three ways: i) by large space antennas orbiting the Earth that could be used for both VLBI and SETI (VSOP and RadioAstron missions), ii) by a radiotelescope inside the Saha far side Moon crater and an Earth-link antenna on the Mare Smythii near side plain. Such SETIMOON mission would require no astronaut work since a Tether, deployed in Moon orbit until the two antennas landed softly, would also be the cable connecting them. Alternatively, a data relay satellite orbiting the Earth-Moon Lagrangian pointL2would avoid the Earthlink antenna, iii) by a large space antenna put at the foci of the Sun gravitational lens: 1) for electromagnetic waves, the minimal focal distance is 550 Astronomical Units (AU) or 14 times beyond Pluto. One could use the huge radio magnifications of sources aligned to the Sun and spacecraft; 2) for gravitational waves and neutrinos, the focus lies between 22.45 and 29.59 AU (Uranus and Neptune orbits), with a flight time of less than 30 years. Two new space missions, of SETI interest if ET’s use neutrinos for communications, are proposed.

Spots on the Sun and Life on the Earth

2019 ◽  
Vol 15 (1) ◽  
pp. 73-77
Author(s):  
Valentina V. Ukraintseva ◽  
Keyword(s):  
The Sun ◽  
The Earth

Forecasting the fl ood situation using space images in the city of Tavda Sverdlovsk region

2018 ◽  
Vol 934 (4) ◽  
pp. 46-52
Author(s):  
A.S. Bruskova ◽  
T.I. Levitskaya ◽  
D.M. Haydukova
Keyword(s):  
Water Levels ◽  
Economic Damage ◽  
Geoinformation System ◽  
Space Images ◽  
Geoinformation Systems ◽  
Emergency Situations ◽  
The Earth ◽  
Maximum Water ◽  
The City

Flooding is a dangerous phenomenon, causing emergency situations and causing material damage, capable of damaging health, and even death of people. To reduce the risk and economic damage from flooding, it is necessary to forecast flooding areas. An effective method of forecasting emergency situations due to flooding is the method of remote sensing of the Earth with integration into geoinformation systems. With the help of satellite imagery, a model of flooding was determined based on the example of Tavda, the Sverdlovsk Region. Space images are loaded into the geoinformation system and on their basis a series of thematic layers is created, which contains information about the zones of possible flooding at given water level marks. The determination of the area of flooding is based on the calculation of the availability of maximum water levels at hydrological stations. According to the calculated security data, for each hydrological post, flood zones are constructed by interpolation between pre-calculated flood zones of standard security. The results of the work can be used by the Main Directorate of the Ministry for Emergency Situations of Russia for the Sverdlovsk Region.

A utopia do direito à cidade: Possibilidades de superação da dicotomia favela-bairro no Rio de Janeiro

GEOgraphia ◽  
2010 ◽  
Vol 7 (14) ◽  
Author(s):  
Márcio Piñon de Oliveira
Keyword(s):  
Rio De Janeiro ◽  
The Other ◽  
Right To The City ◽  
Other Hand ◽  
The Right ◽  
The City

A utopia do direito à cidade,  no  caso específico do Rio de Janeiro, começa, obrigatoriamente, pela  superação da visão dicotômica favela-cidade. Para isso, é preciso que os moradores da favela possam sentir-se tão cidadãos quanto os que têm moradias fora das favelas. A utopia do direito à cidade tem de levar a favela a própria utopia da cidade. Uma cidade que não se fragmente em oposições asfalto-favela, norte-sul, praia-subúrbio e onde todos tenham direito ao(s) seu(s) centro(s). Oposições que expressam muito mais do que diferenças de  localização e que  se apresentam recheadas de  segregação, estereótipos e  ideologias. Por outro  lado, o direito a cidade, como possibilidade histórica, não pode ser pensado exclusivamente a partir da  favela. Mas as populações  que aí habitam guardam uma contribuição inestimável para  a  construção prática  desse direito. Isso porque,  das  experiências vividas, emergem aprendizados e frutificam esperanças e soluções. Para que a favela seja pólo de um desejo que impulsione a busca do direito a cidade, é necessário que ela  se  pense como  parte da história da própria cidade  e sua transformação  em metrópole.Abstract The right  to the city's  utopy  specifically  in Rio de Janeiro, begins by surpassing  the dichotomy approach between favela and the city. For this purpose, it is necessary, for the favela dwellers, the feeling of citizens as well as those with home outside the favelas. The right to the city's utopy must bring to the favela  the utopy to the city in itself- a non-fragmented city in terms of oppositions like "asphalt"-favela, north-south, beach-suburb and where everybody has right to their center(s). These oppositions express much more the differences of location and present  themselves full of segregation, stereotypes and ideologies. On  the other  hand, the right to  the city, as historical possibility, can not be thought  just from the favela. People that live there have a contribution for a practical construction of this right. 

Much Ado about (Practically) Nothing

2010 ◽  
Author(s):  
David Fisher
Keyword(s):  
Energy Source ◽  
Atomic Nucleus ◽  
The Sun ◽  
Scientific Journals ◽  
Rare Gases ◽  
Important Work ◽  
The Earth ◽  
Wide Range ◽  
Life On Mars ◽  
The Universe

There are eight columns in the Periodic Table. The eighth column is comprised of the rare gases, so-called because they are the rarest elements on earth. They are also called the inert or noble gases because, like nobility, they do no work. They are colorless, odorless, invisible gases which do not react with anything, and were thought to be unimportant until the early 1960s. Starting in that era, David Fisher has spent roughly fifty years doing research on these gases, publishing nearly a hundred papers in the scientific journals, applying them to problems in geophysics and cosmochemistry, and learning how other scientists have utilized them to change our ideas about the universe, the sun, and our own planet. Much Ado about (Practically) Nothing will cover this spectrum of ideas, interspersed with the author's own work which will serve to introduce each gas and the important work others have done with them. The rare gases have participated in a wide range of scientific advances-even revolutions-but no book has ever recorded the entire story. Fisher will range from the intricacies of the atomic nucleus and the tiniest of elementary particles, the neutrino, to the energy source of the stars; from the age of the earth to its future energies; from life on Mars to cancer here on earth. A whole panoply that has never before been told as an entity.

Dombey and Son

2008 ◽  
Author(s):  
Charles Dickens ◽  
Dennis Walder
Keyword(s):  
Family Relationships ◽  
The Sun ◽  
The Novel ◽  
The Earth ◽  
The Future ◽  
Original Illustrations ◽  
The One

Dombey and Son ... Those three words conveyed the one idea of Mr. Dombey's life. The earth was made for Dombey and Son to trade in, and the sun and moon were made to give them light.' The hopes of Mr Dombey for the future of his shipping firm are centred on his delicate son Paul, and Florence, his devoted daughter, is unloved and neglected. When the firm faces ruin, and Dombey's second marriage ends in disaster, only Florence has the strength and humanity to save her father from desolate solitude. This new edition contains Dickens's prefaces, his working plans, and all the original illustrations by ‘Phiz’. The text is that of the definitive Clarendon edition. It has been supplemented by a wide-ranging Introduction, highlighting Dickens's engagement with his times, and the touching exploration of family relationships which give the novel added depth and relevance.

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