|
Marcel Minnaert
Marcel Gilles Jozef Minnaert (12 February 1893 – 26 October 1970) was a Dutch astronomer of Belgian origin. He was born in Bruges and died in Utrecht. He is notable for his contributions to astronomy and physics and for a popular book on meteorological optics: ''Light and colour in the open air'', first published in English in 1940. Biography Minnaert obtained a PhD in biology at Ghent University in 1914. Later he obtained also a PhD in physics from Utrecht University, under the supervision of Leonard Ornstein. He was a supporter of the Flemish movement during World War I and endorsed the replacement of French by Dutch during the German occupation of Belgium. He worked as "lector fysica" at the new Flemish University of Ghent, which was made possible by the support of the German occupation forces, and was viewed as connivance with the enemy by the reestablished Belgian authorities. Because of this, he was sentenced after the war in absence to 15 years of forced labor. How ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruges
Bruges ( , nl, Brugge ) is the capital and largest city A city is a human settlement of notable size.Goodall, B. (1987) ''The Penguin Dictionary of Human Geography''. London: Penguin.Kuper, A. and Kuper, J., eds (1996) ''The Social Science Encyclopedia''. 2nd edition. London: Routledge. It can be def ... of the Provinces of Belgium, province of West Flanders in the Flemish Region of Belgium, in the northwest of the country, and the sixth-largest city of the country by population. The area of the whole city amounts to more than 13,840 hectares (138.4 km2; 53.44 sq miles), including 1,075 hectares off the coast, at Zeebrugge (from , meaning 'Bruges by the Sea'). The historic city centre is a prominent World Heritage Site of UNESCO. It is oval in shape and about 430 hectares in size. The city's total population is 117,073 (1 January 2008), [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which relates to the order of nature, or, in other words, to the regular succession of events." Physics is one of the most fundamental scientific disciplines, with its main goal being to understand how the universe behaves. "Physics is one of the most fundamental of the sciences. Scientists of all disciplines use the ideas of physics, including chemists who study the structure of molecules, paleontologists who try to reconstruct how dinosaurs walked, and climatologists who study how human activities affect the atmosphere and oceans. Physics is also the foundation of all engineering and technology. No engineer could design a flat-screen TV, an interplanetary spacecraft, or even a better mousetrap without first understanding the basic laws of physics ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liquid Bubble
A bubble is a globule of one substance in another, usually gas in a liquid. Due to the Marangoni effect, bubbles may remain intact when they reach the surface of the immersive substance. Common examples Bubbles are seen in many places in everyday life, for example: * As spontaneous nucleation of supersaturated carbon dioxide in soft drinks * As water vapor in boiling water * As air mixed into agitated water, such as below a waterfall * As sea foam * As a soap bubble * As given off in chemical reactions, e.g., baking soda + vinegar * As a gas trapped in glass during its manufacture * As the indicator in a spirit level Physics and chemistry Bubbles form and coalesce into globular shapes because those shapes are at a lower energy state. For the physics and chemistry behind it, see nucleation. Appearance Bubbles are visible because they have a different refractive index (RI) than the surrounding substance. For example, the RI of air is approximately 1.0003 and the RI of w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curve Of Growth
In astronomy, the curve of growth describes the equivalent width of a spectral line A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from emission or absorption of light in a narrow frequency range, compared with the nearby frequencies. Spectral lines are often used to iden ... as a function of the column density of the material from which the spectral line is observed. References {{astronomy-stub Spectroscopy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Atmosphere
The stellar atmosphere is the outer region of the volume of a star, lying above the stellar core, radiation zone and convection zone. Overview The stellar atmosphere is divided into several regions of distinct character: * The photosphere, which is the atmosphere's lowest and coolest layer, is normally its only visible part. Light escaping from the surface of the star stems from this region and passes through the higher layers. The Sun's photosphere has a temperature in the 5,770 K to 5,780 K range. Starspots, cool regions of disrupted magnetic field lie on the photosphere. * Above the photosphere lies the chromosphere. This part of the atmosphere first cools down and then starts to heat up to about 10 times the temperature of the photosphere. * Above the chromosphere lies the transition region, where the temperature increases rapidly on a distance of only around 100 km. * The outermost part of the stellar atmosphere is the corona, a tenuous plasma which ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spectroscopy
Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter waves and acoustic waves can also be considered forms of radiative energy, and recently gravitational waves have been associated with a spectral signature in the context of the Laser Interferometer Gravitational-Wave Observatory (LIGO) In simpler terms, spectroscopy is the precise study of color as generalized from visible light to all bands of the electromagnetic spectrum. Historically, spectroscopy originated as the study of the wavelength dependence of the absorption by gas phase matter of visible light dispersed by a prism. Spectroscopy, primarily in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of astronomy, chemistry, materials science, and physics, allowing the composition, physical structure an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Utrecht (city)
Utrecht ( , , ) is the fourth-largest city and a municipality of the Netherlands, capital and most populous city of the province of Utrecht. It is located in the eastern corner of the Randstad conurbation, in the very centre of mainland Netherlands, about 35 km south east of the capital Amsterdam and 45 km north east of Rotterdam. It has a population of 361,966 as of 1 December 2021. Utrecht's ancient city centre features many buildings and structures, several dating as far back as the High Middle Ages. It has been the religious centre of the Netherlands since the 8th century. It was the most important city in the Netherlands until the Dutch Golden Age, when it was surpassed by Amsterdam as the country's cultural centre and most populous city. Utrecht is home to Utrecht University, the largest university in the Netherlands, as well as several other institutions of higher education. Due to its central position within the country, it is an important hub for both rail and ro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photometry (optics)
Photometry is the science of the measurement of light, in terms of its perceived brightness to the human eye. It is distinct from radiometry, which is the science of measurement of radiant energy (including light) in terms of absolute power. In modern photometry, the radiant power at each wavelength is weighted by a luminosity function that models human brightness sensitivity. Typically, this weighting function is the photopic sensitivity function, although the scotopic function or other functions may also be applied in the same way. Photometry and the eye The human eye is not equally sensitive to all wavelengths of visible light. Photometry attempts to account for this by weighting the measured power at each wavelength with a factor that represents how sensitive the eye is at that wavelength. The standardized model of the eye's response to light as a function of wavelength is given by the luminosity function. The eye has different responses as a function of wavelength w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Front (World War I)
The Western Front was one of the main theatres of war during the First World War. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The German advance was halted with the Battle of the Marne. Following the Race to the Sea, both sides dug in along a meandering line of fortified trenches, stretching from the North Sea to the Swiss frontier with France, which changed little except during early 1917 and in 1918. Between 1915 and 1917 there were several offensives along this front. The attacks employed massive artillery bombardments and massed infantry advances. Entrenchments, machine gun emplacements, barbed wire and artillery repeatedly inflicted severe casualties during attacks and counter-attacks and no significant advances were made. Among the most costly of these offensives were the Battle of Verdun, in 1916, with a combined 700 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dutch Language
Dutch ( ) is a West Germanic language spoken by about 25 million people as a first language and 5 million as a second language. It is the third most widely spoken Germanic language, after its close relatives German and English. '' Afrikaans'' is a separate but somewhat mutually intelligible daughter languageAfrikaans is a daughter language of Dutch; see , , , , , . Afrikaans was historically called Cape Dutch; see , , , , , . Afrikaans is rooted in 17th-century dialects of Dutch; see , , , . Afrikaans is variously described as a creole, a partially creolised language, or a deviant variety of Dutch; see . spoken, to some degree, by at least 16 million people, mainly in South Africa and Namibia, evolving from the Cape Dutch dialects of Southern Africa. The dialects used in Belgium (including Flemish) and in Suriname, meanwhile, are all guided by the Dutch Language Union. In Europe, most of the population of the Netherlands (where it is the only official language sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
French Language
French ( or ) is a Romance language of the Indo-European family. It descended from the Vulgar Latin of the Roman Empire, as did all Romance languages. French evolved from Gallo-Romance, the Latin spoken in Gaul, and more specifically in Northern Gaul. Its closest relatives are the other langues d'oïl—languages historically spoken in northern France and in southern Belgium, which French (Francien) largely supplanted. French was also influenced by native Celtic languages of Northern Roman Gaul like Gallia Belgica and by the ( Germanic) Frankish language of the post-Roman Frankish invaders. Today, owing to France's past overseas expansion, there are numerous French-based creole languages, most notably Haitian Creole. A French-speaking person or nation may be referred to as Francophone in both English and French. French is an official language in 29 countries across multiple continents, most of which are members of the '' Organisation internationale de la Francopho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fighting occurring throughout Europe, the Middle East, Africa, the Pacific Ocean, Pacific, and parts of Asia. An estimated 9 million soldiers were killed in combat, plus another 23 million wounded, while 5 million civilians died as a result of military action, hunger, and disease. Millions more died in Genocides in history (World War I through World War II), genocides within the Ottoman Empire and in the Spanish flu, 1918 influenza pandemic, which was exacerbated by the movement of combatants during the war. Prior to 1914, the European great powers were divided between the Triple Entente (comprising French Third Republic, France, Russia, and British Empire, Britain) and the Triple A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Bruges")
.jpg "Click for more on -> Utrecht (city)")
