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Gömböc Structure
The Gömböc ( ) is the first known physical example of a class of convex three-dimensional homogeneous bodies, called mono-monostatic, which, when resting on a flat surface have just one stable and one unstable point of equilibrium. The existence of this class was conjectured by the Russian mathematician Vladimir Arnold in 1995 and proven in 2006 by the Hungarian scientists Gábor Domokos and Péter Várkonyi by constructing at first a mathematical example and subsequently a physical example. Mono-monostatic shapes exist in countless varieties, most of which are close to a sphere, with a stringent shape tolerance (about one part in a thousand). Gömböc is the first mono-monostatic shape which has been constructed physically. It has a sharpened top, as shown in the photo. Its shape helped to explain the body structure of some tortoises in relation to their ability to return to an equilibrium position after being placed upside down. Copies of the Gömböc have been donat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gömböc
The Gömböc ( ) is the first known physical example of a class of convex three-dimensional homogeneous bodies, called mono-monostatic, which, when resting on a flat surface have just one stable and one unstable point of equilibrium. The existence of this class was conjectured by the Russian mathematician Vladimir Arnold in 1995 and proven in 2006 by the Hungarian scientists Gábor Domokos and Péter Várkonyi by constructing at first a mathematical example and subsequently a physical example. Mono-monostatic shapes exist in countless varieties, most of which are close to a sphere, with a stringent shape tolerance (about one part in a thousand). Gömböc is the first mono-monostatic shape which has been constructed physically. It has a sharpened top, as shown in the photo. Its shape helped to explain the body structure of some tortoises in relation to their ability to return to an equilibrium position after being placed upside down. Copies of the Gömböc have been donate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weeble
Weebles is a range of children's roly-poly toys originating in the US in Hasbro's Playskool division on July 23, 1971. Tipping an egg (biology), egg-shaped Weeble causes a weight located at the bottom-center to be lifted off the ground. Once released, gravity brings the Weeble back into an upright position. Weebles have been designed with a variety of shapes, including some designed to look like people or animals. The catchphrase "Weebles wobble, but they don't fall down" was used in advertising during their rise in popularity in the 1970s and during successive relaunches in the early 2000s. The line was coined by advertising executive Walter Cohen. Walter Cohen created the phrase when he and his partner Bernard Most, were assigned to the account at Benton & Bowles (B&B) in 1971. Walter and Bernard (as the creative team Bernie & Walter) used the phrase when they created the first TV commercials for the new Hasbro product, Weebles. Mitch Reed was the account executive assigned to t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hungarian Museum Of Natural History
Hungarian may refer to: * Hungary, a country in Central Europe * Kingdom of Hungary, state of Hungary, existing between 1000 and 1946 * Hungarians, ethnic groups in Hungary * Hungarian algorithm, a polynomial time algorithm for solving the assignment problem * Hungarian language, a Finno-Ugric language spoken in Hungary and all neighbouring countries * Hungarian notation, a naming convention in computer programming * Hungarian cuisine Hungarian or Magyar cuisine is the cuisine characteristic of the nation of Hungary and its primary ethnic group, the Magyars. Traditional Hungarian dishes are primarily based on meats, seasonal vegetables, fruits, bread, and dairy products. ..., the cuisine of Hungary and the Hungarians See also * * {{disambiguation Language and nationality disambiguation pages ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Budapest Zoo And Botanical Garden
Zoo & Botanical Garden of the Capital ( hu, Fővárosi Állat- és Növénykert) is the oldest zoo park in Hungary and one of the oldest in the world. It has 1,072 animal species and is located within Városliget Park, unusually for a zoo, it is in the centre of the city. The zoo opened its doors on 9 August 1866. The park has 1–1.1 million visitors every year. The area is a nature reserve, and has some valuable art nouveau buildings designed by Kornél Neuschloss and Károly Kós. More than 1,000 species are living there. The most special animals that are present in the zoo are the Komodo dragon and from December 2011 the wombat. The zoo is located in the city centre and can be reached by Line 1 (Budapest Metro) Official city card (Budapest card) owners get a 25% discount for a single ticket into the zoo. History The Budapest Zoo and Botanical Garden is one of the oldest in the world. The idea of the foundation dates back to 1820-30s but it opened only on 9 August 1866. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Shell
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the larger kinds of exoskeletons are known as " shells". Examples of exoskeletons within animals include the arthropod exoskeleton shared by chelicerates, myriapods, crustaceans, and insects, as well as the shell of certain sponges and the mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some animals, such as the turtle, have both an endoskeleton and an exoskeleton. Role Exoskeletons contain rigid and resistant components that fulfill a set of functional roles in many animals including protection, excretion, sensing, support, feeding and acting as a barrier against desiccation in terrestrial organisms. Exoskeletons have a role in defense from pests and predators, support and in providing an attachment framework for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Indian Star Tortoise Tennoji
Indian or Indians may refer to: Peoples South Asia * Indian people, people of Indian nationality, or people who have an Indian ancestor ** Non-resident Indian, a citizen of India who has temporarily emigrated to another country * South Asian ethnic groups, referring to people of the Indian subcontinent, as well as the greater South Asia region prior to the 1947 partition of India * Anglo-Indians, people with mixed Indian and British ancestry, or people of British descent born or living in the Indian subcontinent * East Indians, a Christian community in India Europe * British Indians, British people of Indian origin The Americas * Indo-Canadians, Canadian people of Indian origin * Indian Americans, American people of Indian origin * Indigenous peoples of the Americas, the pre-Columbian inhabitants of the Americas and their descendants ** Plains Indians, the common name for the Native Americans who lived on the Great Plains of North America ** Native Americans in the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhodes
Rhodes (; el, Ρόδος , translit=Ródos ) is the largest and the historical capital of the Dodecanese islands of Greece. Administratively, the island forms a separate municipality within the Rhodes regional unit, which is part of the South Aegean administrative region. The principal town of the island and seat of the municipality is Rhodes. The city of Rhodes had 50,636 inhabitants in 2011. In 2022 the island has population of 124,851 people. It is located northeast of Crete, southeast of Athens. Rhodes has several nicknames, such as "Island of the Sun" due to its patron sun god Helios, "The Pearl Island", and "The Island of the Knights", named after the Knights of Saint John of Jerusalem, who ruled the island from 1310 to 1522. Historically, Rhodes was famous for the Colossus of Rhodes, one of the Seven Wonders of the Ancient World. The Medieval Old Town of the City of Rhodes has been declared a World Heritage Site. Today, it is one of the most popular tourist destina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Greece
Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to the northeast. The Aegean Sea lies to the east of the Geography of Greece, mainland, the Ionian Sea to the west, and the Sea of Crete and the Mediterranean Sea to the south. Greece has the longest coastline on the Mediterranean Basin, featuring List of islands of Greece, thousands of islands. The country consists of nine Geographic regions of Greece, traditional geographic regions, and has a population of approximately 10.4 million. Athens is the nation's capital and List of cities and towns in Greece, largest city, followed by Thessaloniki and Patras. Greece is considered the cradle of Western culture, Western civilization, being the birthplace of Athenian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Degeneracy (mathematics)
In mathematics, a degenerate case is a limiting case of a class of objects which appears to be qualitatively different from (and usually simpler than) the rest of the class, and the term degeneracy is the condition of being a degenerate case. The definitions of many classes of composite or structured objects often implicitly include inequalities. For example, the angles and the side lengths of a triangle are supposed to be positive. The limiting cases, where one or several of these inequalities become equalities, are degeneracies. In the case of triangles, one has a ''degenerate triangle'' if at least one side length or angle is zero. Equivalently, it becomes a "line segment". Often, the degenerate cases are the exceptional cases where changes to the usual dimension or the cardinality of the object (or of some part of it) occur. For example, a triangle is an object of dimension two, and a degenerate triangle is contained in a line, which makes its dimension one. This is similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gömböc Structure
The Gömböc ( ) is the first known physical example of a class of convex three-dimensional homogeneous bodies, called mono-monostatic, which, when resting on a flat surface have just one stable and one unstable point of equilibrium. The existence of this class was conjectured by the Russian mathematician Vladimir Arnold in 1995 and proven in 2006 by the Hungarian scientists Gábor Domokos and Péter Várkonyi by constructing at first a mathematical example and subsequently a physical example. Mono-monostatic shapes exist in countless varieties, most of which are close to a sphere, with a stringent shape tolerance (about one part in a thousand). Gömböc is the first mono-monostatic shape which has been constructed physically. It has a sharpened top, as shown in the photo. Its shape helped to explain the body structure of some tortoises in relation to their ability to return to an equilibrium position after being placed upside down. Copies of the Gömböc have been donat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ellipse Evolute
In mathematics, an ellipse is a plane curve surrounding two focus (geometry), focal points, such that for all points on the curve, the sum of the two distances to the focal points is a constant. It generalizes a circle, which is the special type of ellipse in which the two focal points are the same. The elongation of an ellipse is measured by its eccentricity (mathematics), eccentricity e, a number ranging from e = 0 (the Limiting case (mathematics), limiting case of a circle) to e = 1 (the limiting case of infinite elongation, no longer an ellipse but a parabola). An ellipse has a simple algebraic solution for its area, but only approximations for its perimeter (also known as circumference), for which integration is required to obtain an exact solution. Analytic geometry, Analytically, the equation of a standard ellipse centered at the origin with width 2a and height 2b is: : \frac+\frac = 1 . Assuming a \ge b, the foci are (\pm c, 0) for c = \sqrt. The standard parametric e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four-vertex Theorem
The four-vertex theorem of geometry states that the curvature along a simple, closed, smooth plane curve has at least four local extrema (specifically, at least two local maxima and at least two local minima). The name of the theorem derives from the convention of calling an extreme point of the curvature function a vertex. This theorem has many generalizations, including a version for space curves where a vertex is defined as a point of vanishing torsion. Definition and examples The curvature at any point of a smooth curve in the plane can be defined as the reciprocal of the radius of an osculating circle at that point, or as the norm of the second derivative of a parametric representation of the curve, parameterized consistently with the length along the curve. For the vertices of a curve to be well-defined, the curvature itself should vary continuously, as happens for curves of smoothness C^2. A vertex is then a local maximum or local minimum of curvature. If the curvature ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
