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Telescope Conjecture
In mathematics, the Ravenel conjectures are a set of mathematical conjectures in the field of stable homotopy theory posed by Douglas Ravenel at the end of a paper published in 1984. It was earlier circulated in preprint. The problems involved have largely been resolved, with all but the "telescope conjecture" being proved in later papers by others. Ravenel's conjectures exerted influence on the field through the founding of the approach of chromatic homotopy theory. The first of the seven conjectures, then the ''nilpotence conjecture'', was proved in 1988 and is now known as the nilpotence theorem. The telescope conjecture, which was fourth on the original list, remains of substantial interest because of its connection with the convergence of an Adams–Novikov spectral sequence. While opinion has been generally against the truth of the original statement, investigations of associated phenomena (for a triangulated category in general) have become a research area in its own right. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
100inchHooker
1 (one, unit, unity) is a number, numeral, and glyph. It is the first and smallest positive integer of the infinite sequence of natural numbers. This fundamental property has led to its unique uses in other fields, ranging from science to sports, where it commonly denotes the first, leading, or top thing in a group. 1 is the unit of counting or measurement, a determiner for singular nouns, and a gender-neutral pronoun. Historically, the representation of 1 evolved from ancient Sumerian and Babylonian symbols to the modern Arabic numeral. In mathematics, 1 is the multiplicative identity, meaning that any number multiplied by 1 equals the same number. 1 is by convention not considered a prime number. In digital technology, 1 represents the "on" state in binary code, the foundation of computing. Philosophically, 1 symbolizes the ultimate reality or source of existence in various traditions. In mathematics The number 1 is the first natural number after 0. Each natural numbe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Accademia Dei Lincei
The (; literally the "Academy of the Lynx-Eyed"), anglicised as the Lincean Academy, is one of the oldest and most prestigious European scientific institutions, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy. Founded in the Papal States in 1603 by Federico Cesi, the academy was named after the lynx, an animal whose sharp vision symbolizes the observational prowess that science requires. Galileo Galilei was the intellectual centre of the academy and adopted "Galileo Galilei Linceo" as his signature. "The Lincei did not long survive the death in 1630 of Cesi, its founder and patron", and "disappeared in 1651." During the nineteenth century, it was revived, first in the Papal States and later in the nation of Italy. Thus the Pontifical Academy of Sciences, established in 1936, claims this heritage as the ''Accademia Pontificia dei Nuovi Lincei (''"Pontifical Academy of the New Lynxes"'')'', founded in 1847, descending from the first two incarnations of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Spherical Aberration
In optics, spherical aberration (SA) is a type of aberration found in optical systems that have elements with spherical surfaces. This phenomenon commonly affects lenses and curved mirrors, as these components are often shaped in a spherical manner for ease of manufacturing. Light rays that strike a spherical surface off-centre are refracted or reflected more or less than those that strike close to the centre. This deviation reduces the quality of images produced by optical systems. The effect of spherical aberration was first identified in the 11th century by Ibn al-Haytham who discussed it in his work Kitāb al-Manāẓir. Overview A spherical lens has an aplanatic point (i.e., no spherical aberration) only at a lateral distance from the optical axis that equals the radius of the spherical surface divided by the index of refraction of the lens material. Spherical aberration makes the focus of telescopes and other instruments less than ideal. This is an important effect, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Parabolic Reflector
A parabolic (or paraboloid or paraboloidal) reflector (or dish or mirror) is a Mirror, reflective surface used to collect or project energy such as light, sound, or radio waves. Its shape is part of a circular paraboloid, that is, the surface generated by a parabola revolving around its axis. The parabolic reflector transforms an incoming plane wave travelling along the axis into a spherical wave converging toward the focus. Conversely, a spherical wave generated by a point source placed in the focus (optics), focus is reflected into a plane wave propagating as a collimated beam along the axis. Parabolic reflectors are used to collect energy from a distant source (for example sound waves or incoming star light). Since the principles of Specular reflection, reflection are reversible, parabolic reflectors can also be used to collimate radiation from an isotropic source into a parallel beam (optics), beam. In optics, parabolic mirrors are used to gather light in reflecting telescop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Allen & Unwin
George Allen & Unwin was a British publishing company formed in 1911 when Sir Stanley Unwin purchased a controlling interest in George Allen & Co. It became one of the leading publishers of the twentieth century and established an Australian subsidiary in 1976. In 1990 Allen & Unwin was sold to HarperCollins, and the Australian branch was the subject of a management buy-out. George Allen & Unwin in the UK George Allen & Sons was established in 1871 by George Allen, with the backing of John Ruskin, becoming George Allen & Co. Ltd. in 1911 when it merged with Swan Sonnenschein and then George Allen & Unwin on 4 August 1914 as a result of Stanley Unwin's purchase of a controlling interest. Frank Arthur Mumby and Frances Helena Swan Stallybrass, Unwin's son Rayner S. Unwin and his nephew Philip helped him to run the company, which published works by Bertrand Russell, Arthur Waley, Roald Dahl, Lancelot Hogben and Thor Heyerdahl. It became well known as J. R. R. Tolkien's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Objective (optics)
In optical engineering, an objective is an optical element that gathers light from an object being observed and Focus (optics), focuses the ray (optics), light rays from it to produce a real image of the object. Objectives can be a single Lens (optics), lens or mirror, or combinations of several optical elements. They are used in microscopes, binoculars, telescopes, cameras, slide projectors, CD players and many other optical instruments. Objectives are also called object lenses, object glasses, or objective glasses. Microscope objectives The objective lens of a microscope is the one at the bottom near the sample. At its simplest, it is a very high-powered magnifying glass, with very short focal length. This is brought very close to the specimen being examined so that the light from the specimen comes to a focus inside the microscope tube. The objective itself is usually a cylinder containing one or more lenses that are typically made of glass; its function is to collect light fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Zacharias Janssen
Zacharias Janssen; also Zacharias Jansen or Sacharias Jansen; 1585 – pre-1632) was a Dutch spectacle-maker who lived most of his life in Middelburg. He is associated with the invention of the first optical telescope and/or the first truly compound microscope, but these claims (made 20 years after his death) may be fabrications put forward by his son. Biography Zacharias Janssen was born in The Hague. Local records seem to indicate he was born in 1585 although a date of birth as early as 1580 or as late as 1588 are also given. His parents were Hans MartensSource: a book by Huib J. Zuidervaart which is to be published in the spring of 2008. The in Middelburg has already been shown a first version of this book. (who may have been a peddler) and Maeyken Meertens, both probably from Antwerp, Belgium. He grew up with his sister Sara in Middelburg, at the time the second most important city of the Netherlands. He was known as a "street seller" who was constantly in trouble with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Jacob Metius
Jacob (Jacobus; sometimes James) Metius (after 1571–1628) was a Dutch instrument-maker and a specialist in grinding lenses. He is primarily known for the patent application he made for an optical telescope in October 1608, a few weeks after Hans Lippershey submitted a patent for the same device. He was the brother of the geometer and astronomer Adriaan Metius. Biography Little is known of Jacob Metius other than he lived his life in Alkmaar. His father was Adriaan Anthonisz, a mathematician/map-maker/military engineer and Alkmaar burgomaster, and his brother was Adriaan Metius. Jacob's date of birth was some time after his brother's (1571). He died in Alkmaar, his death date usually given in sources as 1628 although some put it between 1624 and 1631. Invention of the telescope In October 1608, the States General discussed Jacob Metius's patent application for a device for "seeing faraway things as though nearby", consisting of a convex and concave lens in a tube, and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hans Lipperhey
Hans Lipperhey ( – buried 29 September 1619), also known as Johann Lippershey or simply Lippershey, was a German- Dutch spectacle-maker. He is commonly associated with the invention of the telescope, because he was the first one who tried to obtain a patent for it. It is, however, unclear if he was the first one to build a telescope. Biography Lipperhey was born in Wesel, now in western Germany, around 1570. He settled in Middelburg, the capital of the province of Zeeland, now in the Netherlands, in 1594, married the same year and became a citizen of Zeeland in 1602. During that time he became a master lens grinder and spectacle maker and established a shop. He remained in Middelburg until his death, in September 1619. Invention of the telescope Hans Lipperhey is known for the earliest written record of a refracting telescope, a patent he filed in 1608. His work with optical devices grew out of his work as a spectacle maker, an industry that had started in Venice and Floren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Large 1923 0668 0003
Large means of great size. Large may also refer to: Mathematics * Arbitrarily large, a phrase in mathematics * Large cardinal, a property of certain transfinite numbers * Large category, a category with a proper class of objects and morphisms (or both) * Large diffeomorphism, a diffeomorphism that cannot be continuously connected to the identity diffeomorphism in mathematics and physics * Large numbers, numbers significantly larger than those ordinarily used in everyday life * Large ordinal, a type of number in set theory * Large sieve, a method of analytic number theory ** Larger sieve, a heightening of the large sieve * Law of large numbers, a result in probability theory * Sufficiently large, a phrase in mathematics Other uses * ''Large'' (film), a 2001 comedy film * Large (surname), an English surname * LARGE, an enzyme * Large, a British English name for the maxima (music), a note length in mensural notation * Large, or G's, or grand, slang for $1,000 US dollars * L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ancient Greek
Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek Dark Ages, Dark Ages (), the Archaic Greece, Archaic or Homeric Greek, Homeric period (), and the Classical Greece, Classical period (). Ancient Greek was the language of Homer and of fifth-century Athens, fifth-century Athenian historians, playwrights, and Ancient Greek philosophy, philosophers. It has contributed many words to English vocabulary and has been a standard subject of study in educational institutions of the Western world since the Renaissance. This article primarily contains information about the Homeric Greek, Epic and Classical periods of the language, which are the best-attested periods and considered most typical of Ancient Greek. From the Hellenistic period (), Ancient Greek was followed by Koine Greek, which is regar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area around Rome, Italy. Through the expansion of the Roman Republic, it became the dominant language in the Italian Peninsula and subsequently throughout the Roman Empire. It has greatly influenced many languages, Latin influence in English, including English, having contributed List of Latin words with English derivatives, many words to the English lexicon, particularly after the Christianity in Anglo-Saxon England, Christianization of the Anglo-Saxons and the Norman Conquest. Latin Root (linguistics), roots appear frequently in the technical vocabulary used by fields such as theology, List of Latin and Greek words commonly used in systematic names, the sciences, List of medical roots, suffixes and prefixes, medicine, and List of Latin legal terms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
