1.
168 (number)
–
168 is the natural number following 167 and preceding 169. 168 is a number, a composite number, an abundant number. There are 168 primes less than 1000,168 is the product of the first two perfect numbers. 168 is the order of the group PSL, the second smallest nonabelian simple group, from Hurwitzs automorphisms theorem,168 is the maximum possible number of automorphisms of a genus 3 Riemann surface, this maximum being achieved by the Klein quartic, whose symmetry group is PSL. The Fano plane has 168 symmetries,168 is the sum of four consecutive prime numbers,37 +41 +43 +47
168 (number)
–
There are 168
pips on a double-six set of
dominoes
2.
Integer
–
An integer is a number that can be written without a fractional component. For example,21,4,0, and −2048 are integers, while 9.75, 5 1⁄2, the set of integers consists of zero, the positive natural numbers, also called whole numbers or counting numbers, and their additive inverses. This is often denoted by a boldface Z or blackboard bold Z standing for the German word Zahlen, ℤ is a subset of the sets of rational and real numbers and, like the natural numbers, is countably infinite. The integers form the smallest group and the smallest ring containing the natural numbers, in algebraic number theory, the integers are sometimes called rational integers to distinguish them from the more general algebraic integers. In fact, the integers are the integers that are also rational numbers. Like the natural numbers, Z is closed under the operations of addition and multiplication, that is, however, with the inclusion of the negative natural numbers, and, importantly,0, Z is also closed under subtraction. The integers form a ring which is the most basic one, in the following sense, for any unital ring. This universal property, namely to be an object in the category of rings. Z is not closed under division, since the quotient of two integers, need not be an integer, although the natural numbers are closed under exponentiation, the integers are not. The following lists some of the properties of addition and multiplication for any integers a, b and c. In the language of algebra, the first five properties listed above for addition say that Z under addition is an abelian group. As a group under addition, Z is a cyclic group, in fact, Z under addition is the only infinite cyclic group, in the sense that any infinite cyclic group is isomorphic to Z. The first four properties listed above for multiplication say that Z under multiplication is a commutative monoid. However, not every integer has an inverse, e. g. there is no integer x such that 2x =1, because the left hand side is even. This means that Z under multiplication is not a group, all the rules from the above property table, except for the last, taken together say that Z together with addition and multiplication is a commutative ring with unity. It is the prototype of all objects of algebraic structure. Only those equalities of expressions are true in Z for all values of variables, note that certain non-zero integers map to zero in certain rings. The lack of zero-divisors in the means that the commutative ring Z is an integral domain
Integer
–
Algebraic structure → Group theory
Group theory
3.
Negative number
–
In mathematics, a negative number is a real number that is less than zero. If positive represents movement to the right, negative represents movement to the left, if positive represents above sea level, then negative represents below level. If positive represents a deposit, negative represents a withdrawal and they are often used to represent the magnitude of a loss or deficiency. A debt that is owed may be thought of as a negative asset, if a quantity may have either of two opposite senses, then one may choose to distinguish between those senses—perhaps arbitrarily—as positive and negative. In the medical context of fighting a tumor, an expansion could be thought of as a negative shrinkage, negative numbers are used to describe values on a scale that goes below zero, such as the Celsius and Fahrenheit scales for temperature. The laws of arithmetic for negative numbers ensure that the common idea of an opposite is reflected in arithmetic. For example, − −3 =3 because the opposite of an opposite is the original thing, negative numbers are usually written with a minus sign in front. For example, −3 represents a quantity with a magnitude of three, and is pronounced minus three or negative three. To help tell the difference between a subtraction operation and a number, occasionally the negative sign is placed slightly higher than the minus sign. Conversely, a number that is greater than zero is called positive, the positivity of a number may be emphasized by placing a plus sign before it, e. g. +3. In general, the negativity or positivity of a number is referred to as its sign, every real number other than zero is either positive or negative. The positive whole numbers are referred to as natural numbers, while the positive and negative numbers are referred to as integers. In bookkeeping, amounts owed are often represented by red numbers, or a number in parentheses, Liu Hui established rules for adding and subtracting negative numbers. By the 7th century, Indian mathematicians such as Brahmagupta were describing the use of negative numbers, islamic mathematicians further developed the rules of subtracting and multiplying negative numbers and solved problems with negative coefficients. Western mathematicians accepted the idea of numbers by the 17th century. Prior to the concept of numbers, mathematicians such as Diophantus considered negative solutions to problems false. Negative numbers can be thought of as resulting from the subtraction of a number from a smaller. For example, negative three is the result of subtracting three from zero,0 −3 = −3, in general, the subtraction of a larger number from a smaller yields a negative result, with the magnitude of the result being the difference between the two numbers
Negative number
–
This thermometer is indicating a negative
Fahrenheit temperature (−4°F).
4.
100 (number)
–
100 or one hundred is the natural number following 99 and preceding 101. In medieval contexts, it may be described as the hundred or five score in order to differentiate the English. The standard SI prefix for a hundred is hecto-,100 is the basis of percentages, with 100% being a full amount. 100 is the sum of the first nine prime numbers, as well as the sum of pairs of prime numbers e. g.3 +97,11 +89,17 +83,29 +71,41 +59. 100 is the sum of the cubes of the first four integers and this is related by Nicomachuss theorem to the fact that 100 also equals the square of the sum of the first four integers,100 =102 =2. 26 +62 =100, thus 100 is a Leyland number and it is divisible by the number of primes below it,25 in this case. It can not be expressed as the difference between any integer and the total of coprimes below it, making it a noncototient and it can be expressed as a sum of some of its divisors, making it a semiperfect number. 100 is a Harshad number in base 10, and also in base 4, there are exactly 100 prime numbers whose digits are in strictly ascending order. 100 is the smallest number whose common logarithm is a prime number,100 senators are in the U. S One hundred is the atomic number of fermium, an actinide. On the Celsius scale,100 degrees is the temperature of pure water at sea level. The Kármán line lies at an altitude of 100 kilometres above the Earths sea level and is used to define the boundary between Earths atmosphere and outer space. There are 100 blasts of the Shofar heard in the service of Rosh Hashana, a religious Jew is expected to utter at least 100 blessings daily. In Hindu Religion - Mythology Book Mahabharata - Dhritarashtra had 100 sons known as kauravas, the United States Senate has 100 Senators. Most of the currencies are divided into 100 subunits, for example, one euro is one hundred cents. The 100 Euro banknotes feature a picture of a Rococo gateway on the obverse, the U. S. hundred-dollar bill has Benjamin Franklins portrait, the Benjamin is the largest U. S. bill in print. American savings bonds of $100 have Thomas Jeffersons portrait, while American $100 treasury bonds have Andrew Jacksons portrait, One hundred is also, The number of years in a century. The number of pounds in an American short hundredweight, in Greece, India, Israel and Nepal,100 is the police telephone number. In Belgium,100 is the ambulance and firefighter telephone number, in United Kingdom,100 is the operator telephone number
100 (number)
–
The
U.S. hundred-dollar bill, Series 2009.
5.
Factorization
–
In mathematics, factorization or factoring is the decomposition of an object into a product of other objects, or factors, which when multiplied together give the original. For example, the number 15 factors into primes as 3 ×5, in all cases, a product of simpler objects is obtained. The aim of factoring is usually to reduce something to “basic building blocks”, such as numbers to prime numbers, factoring integers is covered by the fundamental theorem of arithmetic and factoring polynomials by the fundamental theorem of algebra. Viètes formulas relate the coefficients of a polynomial to its roots, the opposite of polynomial factorization is expansion, the multiplying together of polynomial factors to an “expanded” polynomial, written as just a sum of terms. Integer factorization for large integers appears to be a difficult problem, there is no known method to carry it out quickly. Its complexity is the basis of the security of some public key cryptography algorithms. A matrix can also be factorized into a product of matrices of special types, One major example of this uses an orthogonal or unitary matrix, and a triangular matrix. There are different types, QR decomposition, LQ, QL, RQ and this situation is generalized by factorization systems. By the fundamental theorem of arithmetic, every integer greater than 1 has a unique prime factorization. Given an algorithm for integer factorization, one can factor any integer down to its constituent primes by repeated application of this algorithm, for very large numbers, no efficient classical algorithm is known. Modern techniques for factoring polynomials are fast and efficient, but use sophisticated mathematical ideas and these techniques are used in the construction of computer routines for carrying out polynomial factorization in Computer algebra systems. This article is concerned with classical techniques. While the general notion of factoring just means writing an expression as a product of simpler expressions, when factoring polynomials this means that the factors are to be polynomials of smaller degree. Thus, while x 2 − y = is a factorization of the expression, another issue concerns the coefficients of the factors. It is not always possible to do this, and a polynomial that can not be factored in this way is said to be irreducible over this type of coefficient, thus, x2 -2 is irreducible over the integers and x2 +4 is irreducible over the reals. In the first example, the integers 1 and -2 can also be thought of as real numbers, and if they are, then x 2 −2 = shows that this polynomial factors over the reals. Similarly, since the integers 1 and 4 can be thought of as real and hence complex numbers, x2 +4 splits over the complex numbers, i. e. x 2 +4 =. The fundamental theorem of algebra can be stated as, Every polynomial of n with complex number coefficients splits completely into n linear factors
Factorization
–
A visual representation of the factorization of cubes using volumes. For a sum of cubes, simply substitute z=-y.
6.
Divisor
–
In mathematics, a divisor of an integer n, also called a factor of n, is an integer m that may be multiplied by some other integer to produce n. In this case one says also that n is a multiple of m, an integer n is divisible by another integer m if m is a divisor of n, this implies dividing n by m leaves no remainder. Under this definition, the statement m ∣0 holds for every m, as before, but with the additional constraint k ≠0. Under this definition, the statement m ∣0 does not hold for m ≠0, in the remainder of this article, which definition is applied is indicated where this is significant. Divisors can be negative as well as positive, although sometimes the term is restricted to positive divisors. For example, there are six divisors of 4, they are 1,2,4, −1, −2, and −4,1 and −1 divide every integer. Every integer is a divisor of itself, every integer is a divisor of 0. Integers divisible by 2 are called even, and numbers not divisible by 2 are called odd,1, −1, n and −n are known as the trivial divisors of n. A divisor of n that is not a divisor is known as a non-trivial divisor. A non-zero integer with at least one divisor is known as a composite number, while the units −1 and 1. There are divisibility rules which allow one to recognize certain divisors of a number from the numbers digits, the generalization can be said to be the concept of divisibility in any integral domain. 7 is a divisor of 42 because 7 ×6 =42 and it can also be said that 42 is divisible by 7,42 is a multiple of 7,7 divides 42, or 7 is a factor of 42. The non-trivial divisors of 6 are 2, −2,3, the positive divisors of 42 are 1,2,3,6,7,14,21,42. 5 ∣0, because 5 ×0 =0, if a ∣ b and b ∣ a, then a = b or a = − b. If a ∣ b and a ∣ c, then a ∣ holds, however, if a ∣ b and c ∣ b, then ∣ b does not always hold. If a ∣ b c, and gcd =1, then a ∣ c, if p is a prime number and p ∣ a b then p ∣ a or p ∣ b. A positive divisor of n which is different from n is called a proper divisor or a part of n. A number that does not evenly divide n but leaves a remainder is called an aliquant part of n, an integer n >1 whose only proper divisor is 1 is called a prime number
Divisor
–
The divisors of 10 illustrated with
Cuisenaire rods: 1, 2, 5, and 10
7.
Greek numerals
–
Greek numerals are a system of writing numbers using the letters of the Greek alphabet. These alphabetic numerals are known as Ionic or Ionian numerals, Milesian numerals. In modern Greece, they are used for ordinal numbers. For ordinary cardinal numbers, however, Greece uses Arabic numerals, attic numerals, which were later adopted as the basis for Roman numerals, were the first alphabetic set. They were acrophonic, derived from the first letters of the names of the numbers represented and they ran =1, =5, =10, =100, =1000, and =10000. 50,500,5000, and 50000 were represented by the letter with minuscule powers of ten written in the top right corner, the same system was used outside of Attica, but the symbols varied with the local alphabets, in Boeotia, was 1000. The present system probably developed around Miletus in Ionia, 19th-century classicists placed its development in the 3rd century BC, the occasion of its first widespread use. The present system uses the 24 letters adopted by Euclid as well as three Phoenician and Ionic ones that were not carried over, digamma, koppa, and sampi. The position of characters within the numbering system imply that the first two were still in use while the third was not. Greek numerals are decimal, based on powers of 10, the units from 1 to 9 are assigned to the first nine letters of the old Ionic alphabet from alpha to theta. Each multiple of one hundred from 100 to 900 was then assigned its own separate letter as well and this alphabetic system operates on the additive principle in which the numeric values of the letters are added together to obtain the total. For example,241 was represented as, in ancient and medieval manuscripts, these numerals were eventually distinguished from letters using overbars, α, β, γ, etc. In medieval manuscripts of the Book of Revelation, the number of the Beast 666 is written as χξϛ, although the Greek alphabet began with only majuscule forms, surviving papyrus manuscripts from Egypt show that uncial and cursive minuscule forms began early. These new letter forms sometimes replaced the ones, especially in the case of the obscure numerals. The old Q-shaped koppa began to be broken up and simplified, the numeral for 6 changed several times. During antiquity, the letter form of digamma came to be avoided in favor of a special numerical one. By the Byzantine era, the letter was known as episemon and this eventually merged with the sigma-tau ligature stigma. In modern Greek, a number of changes have been made
Greek numerals
–
Numeral systems
Greek numerals
–
A
Constantinopolitan map of the British Isles from
Ptolemy 's
Geography (c. 1300), using Greek numerals for its
graticule: 52–63°N of the
equator and 6–33°E from Ptolemy's
Prime Meridian at the
Fortunate Isles.
8.
Roman numerals
–
The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin alphabet, Roman numerals, as used today, are based on seven symbols, The use of Roman numerals continued long after the decline of the Roman Empire. The numbers 1 to 10 are usually expressed in Roman numerals as follows, I, II, III, IV, V, VI, VII, VIII, IX, Numbers are formed by combining symbols and adding the values, so II is two and XIII is thirteen. Symbols are placed left to right in order of value. Named after the year of its release,2014 as MMXIV, the year of the games of the XXII Olympic Winter Games The standard forms described above reflect typical modern usage rather than a universally accepted convention. Usage in ancient Rome varied greatly and remained inconsistent in medieval, Roman inscriptions, especially in official contexts, seem to show a preference for additive forms such as IIII and VIIII instead of subtractive forms such as IV and IX. Both methods appear in documents from the Roman era, even within the same document, double subtractives also occur, such as XIIX or even IIXX instead of XVIII. Sometimes V and L are not used, with such as IIIIII. Such variation and inconsistency continued through the period and into modern times. Clock faces that use Roman numerals normally show IIII for four o’clock but IX for nine o’clock, however, this is far from universal, for example, the clock on the Palace of Westminster in London uses IV. Similarly, at the beginning of the 20th century, different representations of 900 appeared in several inscribed dates. For instance,1910 is shown on Admiralty Arch, London, as MDCCCCX rather than MCMX, although Roman numerals came to be written with letters of the Roman alphabet, they were originally independent symbols. The Etruscans, for example, used
Roman numerals
–
Entrance to section LII (52) of the
Colosseum, with numerals still visible
Roman numerals
–
Numeral systems
Roman numerals
–
A typical
clock face with Roman numerals in
Bad Salzdetfurth, Germany
Roman numerals
–
An inscription on
Admiralty Arch, London. The number is 1910, for which MCMX would be more usual
9.
Binary number
–
The base-2 system is a positional notation with a radix of 2. Because of its implementation in digital electronic circuitry using logic gates. Each digit is referred to as a bit, the modern binary number system was devised by Gottfried Leibniz in 1679 and appears in his article Explication de lArithmétique Binaire. Systems related to binary numbers have appeared earlier in multiple cultures including ancient Egypt, China, Leibniz was specifically inspired by the Chinese I Ching. The scribes of ancient Egypt used two different systems for their fractions, Egyptian fractions and Horus-Eye fractions, the method used for ancient Egyptian multiplication is also closely related to binary numbers. This method can be seen in use, for instance, in the Rhind Mathematical Papyrus, the I Ching dates from the 9th century BC in China. The binary notation in the I Ching is used to interpret its quaternary divination technique and it is based on taoistic duality of yin and yang. Eight trigrams and a set of 64 hexagrams, analogous to the three-bit and six-bit binary numerals, were in use at least as early as the Zhou Dynasty of ancient China. The Song Dynasty scholar Shao Yong rearranged the hexagrams in a format that resembles modern binary numbers, the Indian scholar Pingala developed a binary system for describing prosody. He used binary numbers in the form of short and long syllables, Pingalas Hindu classic titled Chandaḥśāstra describes the formation of a matrix in order to give a unique value to each meter. The binary representations in Pingalas system increases towards the right, the residents of the island of Mangareva in French Polynesia were using a hybrid binary-decimal system before 1450. Slit drums with binary tones are used to encode messages across Africa, sets of binary combinations similar to the I Ching have also been used in traditional African divination systems such as Ifá as well as in medieval Western geomancy. The base-2 system utilized in geomancy had long been applied in sub-Saharan Africa. Leibnizs system uses 0 and 1, like the modern binary numeral system, Leibniz was first introduced to the I Ching through his contact with the French Jesuit Joachim Bouvet, who visited China in 1685 as a missionary. Leibniz saw the I Ching hexagrams as an affirmation of the universality of his own beliefs as a Christian. Binary numerals were central to Leibnizs theology and he believed that binary numbers were symbolic of the Christian idea of creatio ex nihilo or creation out of nothing. Is not easy to impart to the pagans, is the ex nihilo through Gods almighty power. In 1854, British mathematician George Boole published a paper detailing an algebraic system of logic that would become known as Boolean algebra
Binary number
–
Numeral systems
Binary number
–
Arithmetic values represented by parts of the Eye of Horus
Binary number
–
Gottfried Leibniz
Binary number
–
George Boole
10.
Ternary numeral system
–
The ternary numeral system has three as its base. Analogous to a bit, a digit is a trit. One trit is equivalent to bits of information. Representations of integer numbers in ternary do not get uncomfortably lengthy as quickly as in binary, for example, decimal 365 corresponds to binary 101101101 and to ternary 111112. However, they are far less compact than the corresponding representations in bases such as decimal – see below for a compact way to codify ternary using nonary. The value of a number with n bits that are all 1 is 2n −1. Then N = M, N = /, and N = bd −1, for a three-digit ternary number, N =33 −1 =26 =2 ×32 +2 ×31 +2 ×30 =18 +6 +2. Nonary or septemvigesimal can be used for representation of ternary. A base-three system is used in Islam to keep track of counting Tasbih to 99 or to 100 on a hand for counting prayers. In certain analog logic, the state of the circuit is often expressed ternary and this is most commonly seen in Transistor–transistor logic using 7406 open collector logic. The output is said to either be low, high, or open, in this configuration the output of the circuit is actually not connected to any voltage reference at all. Where the signal is usually grounded to a reference, or at a certain voltage level. Thus, the voltage level is sometimes unpredictable. A rare ternary point is used to denote fractional parts of an inning in baseball, since each inning consists of three outs, each out is considered one third of an inning and is denoted as.1. For example, if a player pitched all of the 4th, 5th and 6th innings, plus 2 outs of the 7th inning, his Innings pitched column for that game would be listed as 3.2, meaning 3⅔. In this usage, only the part of the number is written in ternary form. Ternary numbers can be used to convey self-similar structures like the Sierpinski triangle or the Cantor set conveniently, additionally, it turns out that the ternary representation is useful for defining the Cantor set and related point sets, because of the way the Cantor set is constructed. The Cantor set consists of the points from 0 to 1 that have an expression that does not contain any instance of the digit 1
Ternary numeral system
–
Numeral systems
11.
Quaternary numeral system
–
Quaternary is the base-4 numeral system. It uses the digits 0,1,2 and 3 to represent any real number. Four is the largest number within the range and one of two numbers that is both a square and a highly composite number, making quaternary a convenient choice for a base at this scale. Despite being twice as large, its economy is equal to that of binary. However, it no better in the localization of prime numbers. See decimal and binary for a discussion of these properties, as with the octal and hexadecimal numeral systems, quaternary has a special relation to the binary numeral system. Each radix 4,8 and 16 is a power of 2, so the conversion to and from binary is implemented by matching each digit with 2,3 or 4 binary digits, for example, in base 4,302104 =11001001002. Although octal and hexadecimal are widely used in computing and computer programming in the discussion and analysis of binary arithmetic and logic, by analogy with byte and nybble, a quaternary digit is sometimes called a crumb. There is a surviving list of Ventureño language number words up to 32 written down by a Spanish priest ca, the Kharosthi numerals have a partial base 4 counting system from 1 to decimal 10. Quaternary numbers are used in the representation of 2D Hilbert curves, here a real number between 0 and 1 is converted into the quaternary system. Every single digit now indicates in which of the respective 4 sub-quadrants the number will be projected, parallels can be drawn between quaternary numerals and the way genetic code is represented by DNA. The four DNA nucleotides in order, abbreviated A, C, G and T, can be taken to represent the quaternary digits in numerical order 0,1,2. With this encoding, the complementary digit pairs 0↔3, and 1↔2 match the complementation of the pairs, A↔T and C↔G. For example, the nucleotide sequence GATTACA can be represented by the quaternary number 2033010, quaternary line codes have been used for transmission, from the invention of the telegraph to the 2B1Q code used in modern ISDN circuits
Quaternary numeral system
–
Numeral systems
12.
Quinary
–
Quinary is a numeral system with five as the base. A possible origination of a system is that there are five fingers on either hand. The base five is stated from 0–4, in the quinary place system, five numerals, from 0 to 4, are used to represent any real number. According to this method, five is written as 10, twenty-five is written as 100, today, the main usage of base 5 is as a biquinary system, which is decimal using five as a sub-base. Another example of a system, is sexagesimal, base 60. Each quinary digit has log25 bits of information, many languages use quinary number systems, including Gumatj, Nunggubuyu, Kuurn Kopan Noot, Luiseño and Saraveca. Gumatj is a true 5–25 language, in which 25 is the group of 5. The Gumatj numerals are shown below, In the video game Riven and subsequent games of the Myst franchise, a decimal system with 2 and 5 as a sub-bases is called biquinary, and is found in Wolof and Khmer. Roman numerals are a biquinary system, the numbers 1,5,10, and 50 are written as I, V, X, and L respectively. Eight is VIII and seventy is LXX, most versions of the abacus use a biquinary system to simulate a decimal system for ease of calculation. Urnfield culture numerals and some tally mark systems are also biquinary, units of currencies are commonly partially or wholly biquinary. A vigesimal system with 4 and 5 as a sub-bases is found in Nahuatl, pentimal system Quibinary Yan Tan Tethera References, Quinary Base Conversion, includes fractional part, from Math Is Fun Media related to Quinary numeral system at Wikimedia Commons
Quinary
–
Numeral systems
13.
Senary
–
The senary numeral system has six as its base. It has been adopted independently by a number of cultures. Like decimal, it is a semiprime, though being the product of the two consecutive numbers that are both prime it has a high degree of mathematical properties for its size. As six is a highly composite number, many of the arguments made in favor of the duodecimal system also apply to this base-6. Senary may be considered interesting in the study of numbers, since all primes other than 2 and 3. That is, for every number p greater than 3, one has the modular arithmetic relations that either p ≡1 or 5. This property maximizes the probability that the result of an integer multiplication will end in zero, E. g. if three fingers are extended on the left hand and four on the right, 34senary is represented. This is equivalent to 3 ×6 +4 which is 22decimal, flipping the sixes hand around to its backside may help to further disambiguate which hand represents the sixes and which represents the units. While most developed cultures count by fingers up to 5 in very similar ways, beyond 5 non-Western cultures deviate from Western methods, such as with Chinese number gestures. More abstract finger counting systems, such as chisanbop or finger binary, allow counting to 99,1,023, or even higher depending on the method. The English monk and historian Bede, in the first chapter of De temporum ratione, titled Tractatus de computo, vel loquela per gestum digitorum, the Ndom language of Papua New Guinea is reported to have senary numerals. Mer means 6, mer an thef means 6 ×2 =12, nif means 36, another example from Papua New Guinea are the Morehead-Maro languages. In these languages, counting is connected to ritualized yam-counting and these languages count from a base six, employing words for the powers of six, running up to 66 for some of the languages. One example is Kómnzo with the numerals, nimbo, féta, tarumba, ntamno, wärämäkä. Some Niger-Congo languages have been reported to use a number system, usually in addition to another. For some purposes, base 6 might be too small a base for convenience. The choice of 36 as a radix is convenient in that the digits can be represented using the Arabic numerals 0–9 and the Latin letters A–Z, this choice is the basis of the base36 encoding scheme. Base36 encoding scheme Binary Ternary Duodecimal Sexagesimal Shacks Base Six Dialectic Digital base 6 clock Analog Clock Designer capable of rendering a base 6 clock Senary base conversion
Senary
–
Numeral systems
Senary
–
34 senary = 22 decimal, in senary finger counting
Senary
14.
Octal
–
The octal numeral system, or oct for short, is the base-8 number system, and uses the digits 0 to 7. Octal numerals can be made from binary numerals by grouping binary digits into groups of three. For example, the representation for decimal 74 is 1001010. Two zeroes can be added at the left,1001010, corresponding the octal digits 112, in the decimal system each decimal place is a power of ten. For example,7410 =7 ×101 +4 ×100 In the octal system each place is a power of eight. The Yuki language in California and the Pamean languages in Mexico have octal systems because the speakers count using the spaces between their fingers rather than the fingers themselves and it has been suggested that the reconstructed Proto-Indo-European word for nine might be related to the PIE word for new. Based on this, some have speculated that proto-Indo-Europeans used a number system. In 1716 King Charles XII of Sweden asked Emanuel Swedenborg to elaborate a number based on 64 instead of 10. Swedenborg however argued that for people with less intelligence than the king such a big base would be too difficult, in 1718 Swedenborg wrote a manuscript, En ny rekenkonst som om vexlas wid Thalet 8 i stelle then wanliga wid Thalet 10. The numbers 1-7 are there denoted by the l, s, n, m, t, f, u. Thus 8 = lo,16 = so,24 = no,64 = loo,512 = looo etc, numbers with consecutive consonants are pronounced with vowel sounds between in accordance with a special rule. Writing under the pseudonym Hirossa Ap-Iccim in The Gentlemans Magazine, July 1745, Hugh Jones proposed a system for British coins, weights. In 1801, James Anderson criticized the French for basing the Metric system on decimal arithmetic and he suggested base 8 for which he coined the term octal. In the mid 19th century, Alfred B. Taylor concluded that Our octonary radix is, therefore, so, for example, the number 65 would be spoken in octonary as under-un. Taylor also republished some of Swedenborgs work on octonary as an appendix to the above-cited publications, in the 2009 film Avatar, the language of the extraterrestrial Navi race employs an octal numeral system, probably due to the fact that they have four fingers on each hand. In the TV series Stargate SG-1, the Ancients, a race of beings responsible for the invention of the Stargates, in the tabletop game series Warhammer 40,000, the Tau race use an octal number system. Octal became widely used in computing systems such as the PDP-8, ICL1900. Octal was an abbreviation of binary for these machines because their word size is divisible by three
Octal
–
Numeral systems
15.
Duodecimal
–
The duodecimal system is a positional notation numeral system using twelve as its base. In this system, the number ten may be written by a rotated 2 and this notation was introduced by Sir Isaac Pitman. These digit forms are available as Unicode characters on computerized systems since June 2015 as ↊ and ↋, other notations use A, T, or X for ten and B or E for eleven. The number twelve is written as 10 in duodecimal, whereas the digit string 12 means 1 dozen and 2 units. Similarly, in duodecimal 100 means 1 gross,1000 means 1 great gross, the number twelve, a superior highly composite number, is the smallest number with four non-trivial factors, and the smallest to include as factors all four numbers within the subitizing range. As a result, duodecimal has been described as the number system. Of its factors,2 and 3 are prime, which means the reciprocals of all 3-smooth numbers have a representation in duodecimal. In particular, the five most elementary fractions all have a terminating representation in duodecimal. This all makes it a convenient number system for computing fractions than most other number systems in common use, such as the decimal, vigesimal, binary. Although the trigesimal and sexagesimal systems do even better in respect, this is at the cost of unwieldy multiplication tables. In this section, numerals are based on decimal places, for example,10 means ten,12 means twelve. Languages using duodecimal number systems are uncommon, germanic languages have special words for 11 and 12, such as eleven and twelve in English. However, they are considered to come from Proto-Germanic *ainlif and *twalif, historically, units of time in many civilizations are duodecimal. There are twelve signs of the zodiac, twelve months in a year, traditional Chinese calendars, clocks, and compasses are based on the twelve Earthly Branches. There are 12 inches in a foot,12 troy ounces in a troy pound,12 old British pence in a shilling,24 hours in a day. The Romans used a system based on 12, including the uncia which became both the English words ounce and inch. The importance of 12 has been attributed to the number of cycles in a year. It is possible to count to 12 with the acting as a pointer
Duodecimal
–
Numeral systems
Duodecimal
–
A duodecimal multiplication table
16.
Hexadecimal
–
In mathematics and computing, hexadecimal is a positional numeral system with a radix, or base, of 16. It uses sixteen distinct symbols, most often the symbols 0–9 to represent values zero to nine, Hexadecimal numerals are widely used by computer system designers and programmers. As each hexadecimal digit represents four binary digits, it allows a more human-friendly representation of binary-coded values, one hexadecimal digit represents a nibble, which is half of an octet or byte. For example, a byte can have values ranging from 00000000 to 11111111 in binary form. In a non-programming context, a subscript is typically used to give the radix, several notations are used to support hexadecimal representation of constants in programming languages, usually involving a prefix or suffix. The prefix 0x is used in C and related languages, where this value might be denoted as 0x2AF3, in contexts where the base is not clear, hexadecimal numbers can be ambiguous and confused with numbers expressed in other bases. There are several conventions for expressing values unambiguously, a numerical subscript can give the base explicitly,15910 is decimal 159,15916 is hexadecimal 159, which is equal to 34510. Some authors prefer a text subscript, such as 159decimal and 159hex, or 159d and 159h. example. com/name%20with%20spaces where %20 is the space character, thus ’, represents the right single quotation mark, Unicode code point number 2019 in hex,8217. In the Unicode standard, a value is represented with U+ followed by the hex value. Color references in HTML, CSS and X Window can be expressed with six hexadecimal digits prefixed with #, white, CSS allows 3-hexdigit abbreviations with one hexdigit per component, #FA3 abbreviates #FFAA33. *nix shells, AT&T assembly language and likewise the C programming language, to output an integer as hexadecimal with the printf function family, the format conversion code %X or %x is used. In Intel-derived assembly languages and Modula-2, hexadecimal is denoted with a suffixed H or h, some assembly languages use the notation HABCD. Ada and VHDL enclose hexadecimal numerals in based numeric quotes, 16#5A3#, for bit vector constants VHDL uses the notation x5A3. Verilog represents hexadecimal constants in the form 8hFF, where 8 is the number of bits in the value, the Smalltalk language uses the prefix 16r, 16r5A3 PostScript and the Bourne shell and its derivatives denote hex with prefix 16#, 16#5A3. For PostScript, binary data can be expressed as unprefixed consecutive hexadecimal pairs, in early systems when a Macintosh crashed, one or two lines of hexadecimal code would be displayed under the Sad Mac to tell the user what went wrong. Common Lisp uses the prefixes #x and #16r, setting the variables *read-base* and *print-base* to 16 can also used to switch the reader and printer of a Common Lisp system to Hexadecimal number representation for reading and printing numbers. Thus Hexadecimal numbers can be represented without the #x or #16r prefix code, MSX BASIC, QuickBASIC, FreeBASIC and Visual Basic prefix hexadecimal numbers with &H, &H5A3 BBC BASIC and Locomotive BASIC use & for hex. TI-89 and 92 series uses a 0h prefix, 0h5A3 ALGOL68 uses the prefix 16r to denote hexadecimal numbers, binary, quaternary and octal numbers can be specified similarly
Hexadecimal
–
Numeral systems
Hexadecimal
–
Bruce Alan Martin's hexadecimal notation proposal
Hexadecimal
–
Hexadecimal finger-counting scheme.
17.
Vigesimal
–
The vigesimal or base 20 numeral system is based on twenty. In a vigesimal system, twenty individual numerals are used. One modern method of finding the extra needed symbols is to write ten as the letter A20, to write nineteen as J20, and this is similar to the common computer-science practice of writing hexadecimal numerals over 9 with the letters A–F. Another method skips over the letter I, in order to avoid confusion between I20 as eighteen and one, so that the number eighteen is written as J20, the number twenty is written as 1020. According to this notation,2020 means forty in decimal = + D020 means two hundred and sixty in decimal = +10020 means four hundred in decimal = + +, in the rest of this article below, numbers are expressed in decimal notation, unless specified otherwise. For example,10 means ten,20 means twenty, in decimal, dividing by three twice only gives one digit periods because 9 is the number below ten. 21, however, the adjacent to 20 that is divisible by 3, is not divisible by 9. Ninths in vigesimal have six-digit periods, the prime factorization of twenty is 22 ×5, so it is not a perfect power. However, its part,5, is congruent to 1. Thus, according to Artins conjecture on primitive roots, vigesimal has infinitely many cyclic primes, but the fraction of primes that are cyclic is not necessarily ~37. 395%. An UnrealScript program that computes the lengths of recurring periods of various fractions in a set of bases found that, of the first 15,456 primes. In many European languages,20 is used as a base, vigesimal systems are common in Africa, for example in Yoruba. Ogún,20, is the basic numeric block, ogójì,40, =20 multiplied by 2. Ogota,60, =20 multiplied by 3, ogorin,80, =20 multiplied by 4. Ogorun,100, =20 multiplied by 5, twenty was a base in the Maya and Aztec number systems. The Maya used the names for the powers of twenty, kal, bak, pic, calab, kinchil. See also Maya numerals and Maya calendar, Mayan languages, Yucatec, the Aztec called them, cempoalli, centzontli, cenxiquipilli, cempoalxiquipilli, centzonxiquipilli and cempoaltzonxiquipilli. Note that the ce prefix at the beginning means one and is replaced with the number to get the names of other multiples of the power
Vigesimal
–
Numeral systems
Vigesimal
–
The
Maya numerals are a base-20 system.
18.
Base 36
–
The senary numeral system has six as its base. It has been adopted independently by a number of cultures. Like decimal, it is a semiprime, though being the product of the two consecutive numbers that are both prime it has a high degree of mathematical properties for its size. As six is a highly composite number, many of the arguments made in favor of the duodecimal system also apply to this base-6. Senary may be considered interesting in the study of numbers, since all primes other than 2 and 3. That is, for every number p greater than 3, one has the modular arithmetic relations that either p ≡1 or 5. This property maximizes the probability that the result of an integer multiplication will end in zero, E. g. if three fingers are extended on the left hand and four on the right, 34senary is represented. This is equivalent to 3 ×6 +4 which is 22decimal, flipping the sixes hand around to its backside may help to further disambiguate which hand represents the sixes and which represents the units. While most developed cultures count by fingers up to 5 in very similar ways, beyond 5 non-Western cultures deviate from Western methods, such as with Chinese number gestures. More abstract finger counting systems, such as chisanbop or finger binary, allow counting to 99,1,023, or even higher depending on the method. The English monk and historian Bede, in the first chapter of De temporum ratione, titled Tractatus de computo, vel loquela per gestum digitorum, the Ndom language of Papua New Guinea is reported to have senary numerals. Mer means 6, mer an thef means 6 ×2 =12, nif means 36, another example from Papua New Guinea are the Morehead-Maro languages. In these languages, counting is connected to ritualized yam-counting and these languages count from a base six, employing words for the powers of six, running up to 66 for some of the languages. One example is Kómnzo with the numerals, nimbo, féta, tarumba, ntamno, wärämäkä. Some Niger-Congo languages have been reported to use a number system, usually in addition to another. For some purposes, base 6 might be too small a base for convenience. The choice of 36 as a radix is convenient in that the digits can be represented using the Arabic numerals 0–9 and the Latin letters A–Z, this choice is the basis of the base36 encoding scheme. Base36 encoding scheme Binary Ternary Duodecimal Sexagesimal Shacks Base Six Dialectic Digital base 6 clock Analog Clock Designer capable of rendering a base 6 clock Senary base conversion
Base 36
–
Numeral systems
Base 36
–
34 senary = 22 decimal, in senary finger counting
Base 36
19.
Natural number
–
In mathematics, the natural numbers are those used for counting and ordering. In common language, words used for counting are cardinal numbers, texts that exclude zero from the natural numbers sometimes refer to the natural numbers together with zero as the whole numbers, but in other writings, that term is used instead for the integers. These chains of extensions make the natural numbers canonically embedded in the number systems. Properties of the numbers, such as divisibility and the distribution of prime numbers, are studied in number theory. Problems concerning counting and ordering, such as partitioning and enumerations, are studied in combinatorics, the most primitive method of representing a natural number is to put down a mark for each object. Later, a set of objects could be tested for equality, excess or shortage, by striking out a mark, the first major advance in abstraction was the use of numerals to represent numbers. This allowed systems to be developed for recording large numbers, the ancient Egyptians developed a powerful system of numerals with distinct hieroglyphs for 1,10, and all the powers of 10 up to over 1 million. A stone carving from Karnak, dating from around 1500 BC and now at the Louvre in Paris, depicts 276 as 2 hundreds,7 tens, and 6 ones, and similarly for the number 4,622. A much later advance was the development of the idea that 0 can be considered as a number, with its own numeral. The use of a 0 digit in place-value notation dates back as early as 700 BC by the Babylonians, the Olmec and Maya civilizations used 0 as a separate number as early as the 1st century BC, but this usage did not spread beyond Mesoamerica. The use of a numeral 0 in modern times originated with the Indian mathematician Brahmagupta in 628, the first systematic study of numbers as abstractions is usually credited to the Greek philosophers Pythagoras and Archimedes. Some Greek mathematicians treated the number 1 differently than larger numbers, independent studies also occurred at around the same time in India, China, and Mesoamerica. In 19th century Europe, there was mathematical and philosophical discussion about the nature of the natural numbers. A school of Naturalism stated that the numbers were a direct consequence of the human psyche. Henri Poincaré was one of its advocates, as was Leopold Kronecker who summarized God made the integers, in opposition to the Naturalists, the constructivists saw a need to improve the logical rigor in the foundations of mathematics. In the 1860s, Hermann Grassmann suggested a recursive definition for natural numbers thus stating they were not really natural, later, two classes of such formal definitions were constructed, later, they were shown to be equivalent in most practical applications. The second class of definitions was introduced by Giuseppe Peano and is now called Peano arithmetic and it is based on an axiomatization of the properties of ordinal numbers, each natural number has a successor and every non-zero natural number has a unique predecessor. Peano arithmetic is equiconsistent with several systems of set theory
Natural number
–
The
Ishango bone (on exhibition at the
Royal Belgian Institute of Natural Sciences) is believed to have been used 20,000 years ago for natural number arithmetic.
Natural number
–
Natural numbers can be used for counting (one
apple, two apples, three apples, …)
20.
Composite number
–
A composite number is a positive integer that can be formed by multiplying together two smaller positive integers. Equivalently, it is an integer that has at least one divisor other than 1. Every positive integer is composite, prime, or the unit 1, so the numbers are exactly the numbers that are not prime. For example, the integer 14 is a number because it is the product of the two smaller integers 2 ×7. Likewise, the integers 2 and 3 are not composite numbers because each of them can only be divided by one, every composite number can be written as the product of two or more primes. For example, the composite number 299 can be written as 13 ×23, and the composite number 360 can be written as 23 ×32 ×5, furthermore and this fact is called the fundamental theorem of arithmetic. There are several known primality tests that can determine whether a number is prime or composite, one way to classify composite numbers is by counting the number of prime factors. A composite number with two prime factors is a semiprime or 2-almost prime, a composite number with three distinct prime factors is a sphenic number. In some applications, it is necessary to differentiate between composite numbers with an odd number of prime factors and those with an even number of distinct prime factors. For the latter μ =2 x =1, while for the former μ =2 x +1 = −1, however, for prime numbers, the function also returns −1 and μ =1. For a number n with one or more repeated prime factors, if all the prime factors of a number are repeated it is called a powerful number. If none of its factors are repeated, it is called squarefree. For example,72 =23 ×32, all the factors are repeated. 42 =2 ×3 ×7, none of the factors are repeated. Another way to classify composite numbers is by counting the number of divisors, all composite numbers have at least three divisors. In the case of squares of primes, those divisors are, a number n that has more divisors than any x < n is a highly composite number. Composite numbers have also been called rectangular numbers, but that name can refer to the pronic numbers, numbers that are the product of two consecutive integers. Table of prime factors Integer factorization Canonical representation of a positive integer Sieve of Eratosthenes Fraleigh, a First Course In Abstract Algebra, Reading, Addison-Wesley, ISBN 0-201-01984-1 Herstein, I. N
Composite number
–
Overview
21.
Centered triangular number
–
A centered triangular number is a centered figurate number that represents a triangle with a dot in the center and all other dots surrounding the center in successive triangular layers. The centered triangular number for n is given by the formula 3 n 2 +3 n +22, each centered triangular number from 10 onwards is the sum of three consecutive regular triangular numbers. Also each centered triangular number has a remainder of 1 when divided by three and the quotient is the regular triangular number. The sum of the first n centered triangular numbers is the constant for an n by n normal magic square for n >2. A centered triangular prime is a triangular number that is prime. The first few centered triangular primes are 19,31,109,199,409, lancelot Hogben, Mathematics for the Million. Republished by W. W. Norton & Company, ISBN 978-0-393-31071-9 Weisstein, Eric W. Centered Triangular Number
Centered triangular number
–
This article has an unclear citation style. The references used may be made clearer with a different or consistent style of
citation,
footnoting, or
external linking. (June 2014)
22.
Mertens function
–
In number theory, the Mertens function is defined for all positive integers n as M = ∑ k =1 n μ where μ is the Möbius function. The function is named in honour of Franz Mertens and this definition can be extended to positive real numbers as follows, M = M. Less formally, M is the count of square-free integers up to x that have a number of prime factors. Because the Möbius function only takes the values −1,0, and +1, the Mertens conjecture went further, stating that there would be no x where the absolute value of the Mertens function exceeds the square root of x. The Mertens conjecture was proven false in 1985 by Andrew Odlyzko, however, the Riemann hypothesis is equivalent to a weaker conjecture on the growth of M, namely M = O. Since high values for M grow at least as fast as the root of x. Here, O refers to Big O notation, the true rate of growth of M is not known. An unpublished conjecture of Steve Gonek states that 0 < lim sup x → ∞ | M | x 5 /4 < ∞, probabilistic evidence towards this conjecture is given by Nathan Ng. Using the Euler product one finds that 1 ζ = ∏ p = ∑ n =1 ∞ μ n s where ζ is the Riemann zeta function and the product is taken over primes. Then, using this Dirichlet series with Perrons formula, one obtains,12 π i ∫ c − i ∞ c + i ∞ x s s ζ d s = M where c >1. Conversely, one has the Mellin transform 1 ζ = s ∫1 ∞ M x s +1 d x which holds for R e >1. A curious relation given by Mertens himself involving the second Chebyshev function is ψ = M log + M log + M log + ⋯. Assuming that there are not multiple non-trivial roots of ζ we have the formula by the residue theorem. Weyl conjectured that the Mertens function satisfied the approximate functional-differential equation y 2 − ∑ r =1 N B2 r. Another formula for the Mertens function is M = ∑ a ∈ F n e 2 π i a where F n is the Farey sequence of order n and this formula is used in the proof of the Franel–Landau theorem. M is the determinant of the n × n Redheffer matrix, using sieve methods similar to those used in prime counting, the Mertens function has been computed for all integers up to an increasing range of x. The Mertens function for all values up to x may be computed in O time. Combinatorial based algorithms can compute isolated values of M in O time, see A084237 for values of M at powers of 10
Mertens function
–
Mertens function to n=10,000
23.
Base 10
–
This article aims to be an accessible introduction. For the mathematical definition, see Decimal representation, the decimal numeral system has ten as its base, which, in decimal, is written 10, as is the base in every positional numeral system. It is the base most widely used by modern civilizations. Decimal fractions have terminating decimal representations and other fractions have repeating decimal representations, Decimal notation is the writing of numbers in a base-ten numeral system. Examples are Brahmi numerals, Greek numerals, Hebrew numerals, Roman numerals, Roman numerals have symbols for the decimal powers and secondary symbols for half these values. Brahmi numerals have symbols for the nine numbers 1–9, the nine decades 10–90, plus a symbol for 100, Chinese numerals have symbols for 1–9, and additional symbols for powers of ten, which in modern usage reach 1072. Positional decimal systems include a zero and use symbols for the ten values to represent any number, positional notation uses positions for each power of ten, units, tens, hundreds, thousands, etc. The position of each digit within a number denotes the multiplier multiplied with that position has a value ten times that of the position to its right. There were at least two independent sources of positional decimal systems in ancient civilization, the Chinese counting rod system. Ten is the number which is the count of fingers and thumbs on both hands, the English word digit as well as its translation in many languages is also the anatomical term for fingers and toes. In English, decimal means tenth, decimate means reduce by a tenth, however, the symbols used in different areas are not identical, for instance, Western Arabic numerals differ from the forms used by other Arab cultures. A decimal fraction is a fraction the denominator of which is a power of ten. g, Decimal fractions 8/10, 1489/100, 24/100000, and 58900/10000 are expressed in decimal notation as 0.8,14.89,0.00024,5.8900 respectively. In English-speaking, some Latin American and many Asian countries, a period or raised period is used as the separator, in many other countries, particularly in Europe. The integer part, or integral part of a number is the part to the left of the decimal separator. The part from the separator to the right is the fractional part. It is usual for a number that consists only of a fractional part to have a leading zero in its notation. Any rational number with a denominator whose only prime factors are 2 and/or 5 may be expressed as a decimal fraction and has a finite decimal expansion. 1/2 =0.5 1/20 =0.05 1/5 =0.2 1/50 =0.02 1/4 =0.25 1/40 =0.025 1/25 =0.04 1/8 =0.125 1/125 =0.008 1/10 =0
Base 10
–
The world's earliest decimal multiplication table was made from bamboo slips, dating from 305 BC, during the
Warring States period in China.
Base 10
–
Numeral systems
Base 10
–
Ten fingers on two hands, the possible starting point of the decimal counting.
Base 10
–
Diagram of the world's earliest decimal multiplication table (c. 305 BC) from the Warring States period
24.
Asteroid belt
–
The asteroid belt is the circumstellar disc in the Solar System located roughly between the orbits of the planets Mars and Jupiter. It is occupied by numerous irregularly shaped bodies called asteroids or minor planets, the asteroid belt is also termed the main asteroid belt or main belt to distinguish it from other asteroid populations in the Solar System such as near-Earth asteroids and trojan asteroids. About half the mass of the belt is contained in the four largest asteroids, Ceres, Vesta, Pallas, the total mass of the asteroid belt is approximately 4% that of the Moon, or 22% that of Pluto, and roughly twice that of Plutos moon Charon. Ceres, the belts only dwarf planet, is about 950 km in diameter, whereas Vesta, Pallas. The remaining bodies range down to the size of a dust particle, the asteroid material is so thinly distributed that numerous unmanned spacecraft have traversed it without incident. Nonetheless, collisions between large asteroids do occur, and these can form a family whose members have similar orbital characteristics. Individual asteroids within the belt are categorized by their spectra. The asteroid belt formed from the solar nebula as a group of planetesimals. Planetesimals are the precursors of the protoplanets. Between Mars and Jupiter, however, gravitational perturbations from Jupiter imbued the protoplanets with too much energy for them to accrete into a planet. Collisions became too violent, and instead of fusing together, the planetesimals, as a result,99. 9% of the asteroid belts original mass was lost in the first 100 million years of the Solar Systems history. Some fragments eventually found their way into the inner Solar System, Asteroid orbits continue to be appreciably perturbed whenever their period of revolution about the Sun forms an orbital resonance with Jupiter. At these orbital distances, a Kirkwood gap occurs as they are swept into other orbits. Classes of small Solar System bodies in other regions are the objects, the centaurs, the Kuiper belt objects, the scattered disc objects, the sednoids. On 22 January 2014, ESA scientists reported the detection, for the first definitive time, of water vapor on Ceres, the detection was made by using the far-infrared abilities of the Herschel Space Observatory. The finding was unexpected because comets, not asteroids, are considered to sprout jets. According to one of the scientists, The lines are becoming more and more blurred between comets and asteroids. This pattern, now known as the Titius–Bode law, predicted the semi-major axes of the six planets of the provided one allowed for a gap between the orbits of Mars and Jupiter
Asteroid belt
–
By far the largest object within the belt is
Ceres. The total mass of the asteroid belt is significantly less than
Pluto 's, and approximately twice that of Pluto's moon
Charon.
Asteroid belt
–
Sun Jupiter trojans Orbits of
planets
Asteroid belt
–
Giuseppe Piazzi, discoverer of
Ceres, the largest object in the asteroid belt. For several decades after its discovery Ceres was known as a planet, after which it was reclassified as asteroid number 1. In 2006 it was recognized to be a dwarf planet.
Asteroid belt
–
951 Gaspra, the first asteroid imaged by a spacecraft, as viewed during
Galileo ' s 1991 flyby; colors are exaggerated
25.
Asteroid
–
Asteroids are minor planets, especially those of the inner Solar System. The larger ones have also been called planetoids and these terms have historically been applied to any astronomical object orbiting the Sun that did not show the disc of a planet and was not observed to have the characteristics of an active comet. As minor planets in the outer Solar System were discovered and found to have volatile-based surfaces that resemble those of comets, in this article, the term asteroid refers to the minor planets of the inner Solar System including those co-orbital with Jupiter. There are millions of asteroids, many thought to be the remnants of planetesimals. The large majority of known asteroids orbit in the belt between the orbits of Mars and Jupiter, or are co-orbital with Jupiter. However, other orbital families exist with significant populations, including the near-Earth objects, individual asteroids are classified by their characteristic spectra, with the majority falling into three main groups, C-type, M-type, and S-type. These were named after and are identified with carbon-rich, metallic. The size of asteroids varies greatly, some reaching as much as 1000 km across, asteroids are differentiated from comets and meteoroids. In the case of comets, the difference is one of composition, while asteroids are composed of mineral and rock, comets are composed of dust. In addition, asteroids formed closer to the sun, preventing the development of the aforementioned cometary ice, the difference between asteroids and meteoroids is mainly one of size, meteoroids have a diameter of less than one meter, whereas asteroids have a diameter of greater than one meter. Finally, meteoroids can be composed of either cometary or asteroidal materials, only one asteroid,4 Vesta, which has a relatively reflective surface, is normally visible to the naked eye, and this only in very dark skies when it is favorably positioned. Rarely, small asteroids passing close to Earth may be visible to the eye for a short time. As of March 2016, the Minor Planet Center had data on more than 1.3 million objects in the inner and outer Solar System, the United Nations declared June 30 as International Asteroid Day to educate the public about asteroids. The date of International Asteroid Day commemorates the anniversary of the Tunguska asteroid impact over Siberia, the first asteroid to be discovered, Ceres, was found in 1801 by Giuseppe Piazzi, and was originally considered to be a new planet. In the early half of the nineteenth century, the terms asteroid. Asteroid discovery methods have improved over the past two centuries. This task required that hand-drawn sky charts be prepared for all stars in the band down to an agreed-upon limit of faintness. On subsequent nights, the sky would be charted again and any moving object would, hopefully, the expected motion of the missing planet was about 30 seconds of arc per hour, readily discernible by observers
Asteroid
–
253 Mathilde, a
C-type asteroid measuring about 50 kilometres (30 mi) across, covered in craters half that size. Photograph taken in 1997 by the
NEAR Shoemaker probe.
Asteroid
–
2013 EC, shown here in radar images, has a provisional designation
Asteroid
–
⚵
Asteroid
–
243 Ida and its moon Dactyl. Dactyl is the first satellite of an asteroid to be discovered.
26.
166P/NEAT
–
166P/NEAT is a periodic comet and centaur in the outer Solar System. It is one of few known bodies with orbits that display a coma, along with 60558 Echeclus,2060 Chiron, 165P/LINEAR. It is also one of the reddest centaurs, 166P/NEAT has a perihelion distance of 8.56 AU, and is a Chiron-type comet with. Orbital simulation from JPL / Ephemeris 166P on Seiichi Yoshidas comet list
166P/NEAT
–
Features
166P/NEAT
–
166P/NEAT
166P/NEAT
27.
Comet
–
Community of Metros is a system of international railway benchmarking. CoMET consists of metro systems from around the world. Each metro has a volume of at least 500 million passengers annually, the four main objectives of CoMET are, To build measures to establish metro best practice. To provide comparative information both for the board and the government. To introduce a system of measures for management and these objectives were discussed in detail at the CoMET Annual Meeting 2016, hosted by SMRT Trains of SMRT Corporation. The meeting was held at Singapore in November 2016, in the UITP conference of 1982, London Underground and Hamburger Hochbahn decided to create a benchmarking exercise to compare their two railways with additional data for other 24 metro systems. The project was successful despite the fact that metros were very different in sizes, structures, however, CoMET used the Key Performance Indicator innovatively to solve the problem. In 1994, the Mass Transit Railway of Hong Kong proposed to London Underground, Berlin U-Bahn, New York City Subway, thus, the metros can exchange performance data and investigate best practice amongst similar heavy metros. These five metros are later known as the Group of Five, over time, other large transit systems joined the group. For example, Mexico City Metro, São Paulo Metro and Tokyo Metro joined in 1996, with eight members in total, the group became known as the Community of Metros. Following the success of the CoMET, the Nova group was created in 1998 as another benchmarking association, the Nova is currently consisted of 14 metro systems from around the world. Later, Moscow Metro joined the CoMET in 1999, madrid Metro transferred from Nova to CoMET in 2004. Santiago Metro and Beijing Subway joined in 2008, taipei Metro was the last member to join the CoMET which also joined in 2010
Comet
–
"CoMET" redirects here. For the geoprofession, see
Geoprofessions § Construction-materials engineering and testing (CoMET).
Comet
28.
Centaur (planetoid)
–
Centaurs are minor planets with a semi-major axis between those of the outer planets. They have unstable orbits that cross or have crossed the orbits of one or more of the giant planets, Centaurs typically behave with characteristics of both asteroids and comets. They are named after the centaurs that were a mixture of horse. It has been estimated there are around 44,000 centaurs in the Solar System with diameters larger than 1 km. The first centaur to be discovered, under the definition of the Jet Propulsion Laboratory, however, they were not recognized as a distinct population until the discovery of 2060 Chiron in 1977. The largest confirmed centaur is 10199 Chariklo, which at 260 km in diameter is as big as a mid-sized main-belt asteroid, however, the lost centaur 1995 SN55 may be somewhat larger. No centaur has been photographed up close, although there is evidence that Saturns moon Phoebe, imaged by the Cassini probe in 2004, in addition, the Hubble Space Telescope has gleaned some information about the surface features of 8405 Asbolus. As of 2008, three centaurs have been found to display comet-like comas, Chiron,60558 Echeclus, and 166P/NEAT, Chiron and Echeclus are therefore classified as both asteroids and comets. Other centaurs, such as 52872 Okyrhoe and 2012 CG, are suspected of having shown comas, any centaur that is perturbed close enough to the Sun is expected to become a comet. The generic definition of a centaur is a body that orbits the Sun between Jupiter and Neptune and crosses the orbits of one or more of the giant planets. Though nowadays the MPC often lists centaurs and scattered disc objects together as a single group, the Jet Propulsion Laboratory similarly defines centaurs as having a semi-major axis, a, between those of Jupiter and Neptune. In contrast, the Deep Ecliptic Survey defines centaurs using a classification scheme. These classifications are based on the change in behavior of the present orbit when extended over 10 million years. The DES defines centaurs as non-resonant objects whose instantaneous perihelia are less than the osculating semi-major axis of Neptune at any time during the simulation and this definition is intended to be synonymous with planet-crossing orbits and to suggest comparatively short lifetimes in the current orbit. The collection The Solar System Beyond Neptune defines objects with an axis between those of Jupiter and Neptune and a Jupiter – Tisserands parameter above 3. The JPL Small-Body Database lists 324 centaurs, there are an additional 65 trans-Neptunian objects with a perihelion closer than the orbit of Uranus. The Committee on Small Body Nomenclature of the International Astronomical Union has not formally weighed in on either side of the debate, thus far, only the binary objects Ceto and Phorcys and Typhon and Echidna have been named according to the new policy. Other objects caught between these differences in classification methods include 944 Hidalgo which was discovered in 1920 and is listed as a centaur in the JPL Small-Body Database
Centaur (planetoid)
–
Features
Centaur (planetoid)
–
Sun Jupiter trojans (6,178)
Scattered disc (>300)
Centaur (planetoid)
29.
Solar system
–
The Solar System is the gravitationally bound system comprising the Sun and the objects that orbit it, either directly or indirectly. Of those objects that orbit the Sun directly, the largest eight are the planets, with the remainder being significantly smaller objects, such as dwarf planets, of the objects that orbit the Sun indirectly, the moons, two are larger than the smallest planet, Mercury. The Solar System formed 4.6 billion years ago from the collapse of a giant interstellar molecular cloud. The vast majority of the mass is in the Sun. The four smaller inner planets, Mercury, Venus, Earth and Mars, are terrestrial planets, being composed of rock. The four outer planets are giant planets, being more massive than the terrestrials. All planets have almost circular orbits that lie within a flat disc called the ecliptic. The Solar System also contains smaller objects, the asteroid belt, which lies between the orbits of Mars and Jupiter, mostly contains objects composed, like the terrestrial planets, of rock and metal. Beyond Neptunes orbit lie the Kuiper belt and scattered disc, which are populations of trans-Neptunian objects composed mostly of ices, within these populations are several dozen to possibly tens of thousands of objects large enough that they have been rounded by their own gravity. Such objects are categorized as dwarf planets, identified dwarf planets include the asteroid Ceres and the trans-Neptunian objects Pluto and Eris. In addition to two regions, various other small-body populations, including comets, centaurs and interplanetary dust clouds. Six of the planets, at least four of the dwarf planets, each of the outer planets is encircled by planetary rings of dust and other small objects. The solar wind, a stream of charged particles flowing outwards from the Sun, the heliopause is the point at which pressure from the solar wind is equal to the opposing pressure of the interstellar medium, it extends out to the edge of the scattered disc. The Oort cloud, which is thought to be the source for long-period comets, the Solar System is located in the Orion Arm,26,000 light-years from the center of the Milky Way. For most of history, humanity did not recognize or understand the concept of the Solar System, the invention of the telescope led to the discovery of further planets and moons. The principal component of the Solar System is the Sun, a G2 main-sequence star that contains 99. 86% of the known mass. The Suns four largest orbiting bodies, the giant planets, account for 99% of the mass, with Jupiter. The remaining objects of the Solar System together comprise less than 0. 002% of the Solar Systems total mass, most large objects in orbit around the Sun lie near the plane of Earths orbit, known as the ecliptic
Solar system
–
The
Sun and
planets of the Solar System (distances not to scale)
Solar system
–
Solar System
Solar system
–
Andreas Cellarius 's illustration of the Copernican system, from the Harmonia Macrocosmica (1660)
Solar system
–
The eight planets of the Solar System (by decreasing size) are
Jupiter,
Saturn,
Uranus,
Neptune,
Earth,
Venus,
Mars and
Mercury.
30.
Star
–
It is primarily present in steroid-producing cells, including theca cells and luteal cells in the ovary, Leydig cells in the testis and cell types in the adrenal cortex. The aqueous phase between two membranes cannot be crossed by the lipophilic cholesterol, unless certain proteins assist in this process. It is now clear that this process is mediated by the action of StAR. The mechanism by which StAR causes cholesterol movement remains unclear as it appears to act from the outside of the mitochondria, some involve StAR transferring cholesterol itself like a shuttle. Another notion is that it causes cholesterol to be kicked out of the membrane to the inner. StAR may also promote the formation of contact sites between the outer and inner mitochondrial membranes to allow cholesterol influx, another suggests that StAR acts in conjunction with PBR, causing the movement of Cl− out of the mitochondria to facilitate contact site formation. However, evidence for an interaction between StAR and PBR remains elusive, in humans, the gene for StAR is located on chromosome 8p11.2 and the protein has 285 amino acids. The signal sequence of StAR that targets it to the mitochondria is clipped off in two steps with import into the mitochondria, phosphorylation at the serine at position 195 increases its activity. The domain of StAR important for promoting cholesterol transfer is the StAR-related transfer domain, StAR is the prototypic member of the START domain family of proteins and is thus also known as STARD1 for START domain-containing protein 1. It is hypothesized that the START domain forms a pocket in StAR that binds single cholesterol molecules for delivery to P450scc, the closest homolog to StAR is MLN64. Together they comprise the StarD1/D3 subfamily of START domain-containing proteins, StAR is a mitochondrial protein that is rapidly synthesized in response to stimulation of the cell to produce steroid. Hormones that stimulate its production depend on the type and include luteinizing hormone, ACTH. At the cellular level, StAR is synthesized typically in response to activation of the second messenger system. StAR has thus far found in all tissues that can produce steroids, including the adrenal cortex, the gonads, the brain. One known exception is the human placenta, mutations in the gene for StAR cause lipoid congenital adrenal hyperplasia, in which patients produce little steroid and can die shortly after birth. Mutations that less severely affect the function of StAR result in nonclassic lipoid CAH or familial glucocorticoid deficiency type 3, all known mutations disrupt StAR function by altering its START domain. In the case of StAR mutation, the phenotype does not present until birth since human placental steroidogenesis is independent of StAR. At the cellular level, the lack of StAR results in an accumulation of lipid within cells
Star
31.
Constellation
–
A constellation is formally defined as a region of the celestial sphere, with boundaries laid down by the International Astronomical Union. The constellation areas mostly had their origins in Western-traditional patterns of stars from which the constellations take their names, in 1922, the International Astronomical Union officially recognized the 88 modern constellations, which cover the entire sky. They began as the 48 classical Greek constellations laid down by Ptolemy in the Almagest, Constellations in the far southern sky are late 16th- and mid 18th-century constructions. 12 of the 88 constellations compose the zodiac signs, though the positions of the constellations only loosely match the dates assigned to them in astrology. The term constellation can refer to the stars within the boundaries of that constellation. Notable groupings of stars that do not form a constellation are called asterisms, when astronomers say something is “in” a given constellation they mean it is within those official boundaries. Any given point in a coordinate system can unambiguously be assigned to a single constellation. Many astronomical naming systems give the constellation in which an object is found along with a designation in order to convey a rough idea in which part of the sky it is located. For example, the Flamsteed designation for bright stars consists of a number, the word constellation seems to come from the Late Latin term cōnstellātiō, which can be translated as set of stars, and came into use in English during the 14th century. It also denotes 88 named groups of stars in the shape of stellar-patterns, the Ancient Greek word for constellation was ἄστρον. Colloquial usage does not draw a distinction between constellation in the sense of an asterism and constellation in the sense of an area surrounding an asterism. The modern system of constellations used in astronomy employs the latter concept, the term circumpolar constellation is used for any constellation that, from a particular latitude on Earth, never sets below the horizon. From the North Pole or South Pole, all constellations south or north of the equator are circumpolar constellations. In the equatorial or temperate latitudes, the term equatorial constellation has sometimes been used for constellations that lie to the opposite the circumpolar constellations. They generally include all constellations that intersect the celestial equator or part of the zodiac, usually the only thing the stars in a constellation have in common is that they appear near each other in the sky when viewed from the Earth. In galactic space, the stars of a constellation usually lie at a variety of distances, since stars also travel on their own orbits through the Milky Way, the star patterns of the constellations change slowly over time. After tens to hundreds of thousands of years, their familiar outlines will become unrecognisable, the terms chosen for the constellation themselves, together with the appearance of a constellation, may reveal where and when its constellation makers lived. The earliest direct evidence for the constellations comes from inscribed stones and it seems that the bulk of the Mesopotamian constellations were created within a relatively short interval from around 1300 to 1000 BC
Constellation
Constellation
Constellation
–
Babylonian tablet recording
Halley's comet in 164 BC.
Constellation
–
Chinese star map with a cylindrical projection (
Su Song)
32.
Andromeda (constellation)
–
Andromeda is one of the 48 constellations listed by the 2nd-century Greco-Roman astronomer Ptolemy and remains one of the 88 modern constellations. Located north of the equator, it is named for Andromeda, daughter of Cassiopeia, in the Greek myth. Andromeda is most prominent during autumn evenings in the Northern Hemisphere, because of its northern declination, Andromeda is visible only north of 40° south latitude, for observers farther south it lies below the horizon. It is one of the largest constellations, with an area of 722 square degrees. This is over 1,400 times the size of the moon, 55% of the size of the largest constellation, Hydra. Its brightest star, Alpha Andromedae, is a star that has also been counted as a part of Pegasus, while Gamma Andromedae is a colorful binary. Only marginally dimmer than Alpha, Beta Andromedae is a red giant, the constellations most obvious deep-sky object is the naked-eye Andromeda Galaxy, the closest spiral galaxy to the Milky Way and one of the brightest Messier objects. Several fainter galaxies, including M31s companions M110 and M32, as well as the more distant NGC891, the Blue Snowball Nebula, a planetary nebula, is visible in a telescope as a blue circular object. Andromeda is the location of the radiant for the Andromedids, a meteor shower that occurs in November. The uranography of Andromeda has its roots most firmly in the Greek tradition, the stars that make up Pisces and the middle portion of modern Andromeda formed a constellation representing a fertility goddess, sometimes named as Anunitum or the Lady of the Heavens. Andromeda is known as the Chained Lady or the Chained Woman in English and it was known as Mulier Catenata in Latin and al-Marat al Musalsalah in Arabic. Offended at her remark, the nymphs petitioned Poseidon to punish Cassiopeia for her insolence, Andromedas panicked father, Cepheus, was told by the Oracle of Ammon that the only way to save his kingdom was to sacrifice his daughter to Cetus. Perseus and Andromeda then married, the myth recounts that the couple had nine children together – seven sons, after Andromedas death Athena placed her in the sky as a constellation, to honor her. Several of the neighboring constellations also represent characters in the Perseus myth and it is connected with the constellation Pegasus. Andromeda was one of the original 48 constellations formulated by Ptolemy in his 2nd-century Almagest, in which it was defined as a specific pattern of stars. She is typically depicted with α Andromedae as her head, ο and λ Andromedae as her chains, and δ, π, μ, Β, however, there is no universal depiction of Andromeda and the stars used to represent her body, head, and chains. Arab astronomers were aware of Ptolemys constellations, but they included a second constellation representing a fish at Andromedas feet, several stars from Andromeda and most of the stars in Lacerta were combined in 1787 by German astronomer Johann Bode to form Frederici Honores. It was designed to honor King Frederick II of Prussia, in 1922, the IAU defined its recommended three-letter abbreviation, And
Andromeda (constellation)
–
Johannes Hevelius 's depiction of Andromeda, from the 1690 edition of his Uranographia. As was conventional for
celestial atlases of the time, the constellation is a mirror image of modern maps as it was drawn from a perspective outside the
celestial sphere.
Andromeda (constellation)
–
List of stars in Andromeda
Andromeda (constellation)
–
Andromeda as depicted in
Urania's Mirror, a set of constellation cards published in London c. 1825, showing the constellation from the inside of the celestial sphere
Andromeda (constellation)
–
Photo of the constellation Andromeda, as it appears to the naked eye. Lines have been added for clarity.
33.
George Patton
–
General George Smith Patton Jr. was a senior officer of the United States Army who commanded the U. S. Seventh Army in the Mediterranean and European theaters of World War II, Third Army in France and Germany following the Allied invasion of Normandy in June 1944. Born in 1885 to a family with a military background, Patton attended the Virginia Military Institute. He studied fencing and designed the M1913 Cavalry Saber, more known as the Patton Sword. Patton first saw combat during the Pancho Villa Expedition in 1916, in the interwar period, Patton remained a central figure in the development of armored warfare doctrine in the U. S. Army, serving in numerous staff positions throughout the country. Rising through the ranks, he commanded the 2nd Armored Division at the time of the American entry into World War II, Seventh Army during the Allied invasion of Sicily, where he was the first Allied commander to reach Messina. Patton returned to command the Third Army following the invasion of Normandy in June 1944 and he led the relief of beleaguered American troops at Bastogne during the Battle of the Bulge, and advanced his Third Army into Nazi Germany by the end of the war. After the war, Patton became the governor of Bavaria. He commanded the United States Fifteenth Army for slightly more than two months, Patton died in Germany on December 21,1945, as a result of injuries from an automobile accident twelve days earlier. Pattons colorful image, hard-driving personality and success as a commander were at times overshadowed by his public statements. His philosophy of leading from the front and his ability to inspire troops with vulgarity-ridden speeches, such as an address to the Third Army. His strong emphasis on rapid and aggressive offensive action proved effective, while Allied leaders held sharply differing opinions on Patton, he was regarded highly by his opponents in the German High Command. A popular, award-winning biographical film released in 1970 helped transform Patton into an American hero, George Smith Patton Jr. was born on November 11,1885 in San Gabriel, California, to George Smith Patton Sr. and his wife Ruth Wilson. Patton had a sister, Anne, who was nicknamed Nita. The family was of Irish, Scots-Irish, English, and Welsh ancestry and his great grandmother came from an aristocratic Welsh family, descended from many Welsh lords of Glamorgan, which had an extensive military background. Patton believed he had former lives as a soldier and took pride in mystical ties with his ancestors, though not directly descended from George Washington, Patton traced some of his English colonial roots to George Washingtons great-grandfather. He was also descended from Englands King Edward I through Edwards son Edmund of Woodstock, family belief held the Pattons were descended from sixteen barons who had signed the Magna Carta. Patton believed in reincarnation, and his ancestry was very important to him, the first Patton in America was Robert Patton, born in Ayr, Scotland
George Patton
–
George S. Patton as a
lieutenant general
George Patton
–
Patton at
Virginia Military Institute
George Patton
–
Patton (at right) fencing in the
modern pentathlon of the
1912 Summer Olympics
George Patton
–
Patton on his steeplechase horse, Wooltex, in 1914
34.
Third Army (United States)
–
The United States Army Central is a military formation of the United States Army, which saw service in World War I and World War II, in the 1991 Gulf War, and in the coalition occupation of Iraq. It is best known for its campaigns in World War II under the command of General George S. Patton, Third Army is currently denoted USARCENT, headquartered at Shaw Air Force Base, South Carolina with a forward element at Camp Arifjan, Kuwait. On the 15th, Major General Joseph T. Dickman assumed command, the third Army consisted of three corps and seven divisions. On 15 November 1918, Major General Dickman was given the mission to move quickly and he was to disarm and disband German forces as ordered by General John J. Pershing, commander of the American Expeditionary Forces. The march into Germany for occupation duty was begun on 17 November 1918, by 15 December the Third Army Headquarters at Mayen opened at Coblenz. Two days later, on 17 December 1918, the Coblenz bridgehead, consisting of a pontoon bridge, Third Army troops had encountered no hostile act of any sort. In the occupied area, both food and coal supplies were sufficient, the crossing of the Rhine by the front line divisions was effected in good time and without confusion. Troops, upon crossing the Rhine and reaching their assigned areas, were billeted preparatory to occupying selected positions for defense. The strength of the Third Army as of 19 December, the date the bridgehead occupation was completed, was 9,638 officers and 221,070 enlisted men, the southern boundary was as has been previously mentioned. Before the advance, the 1st Division passed to the command of the III Corps, the four bridges available for crossing the river within the Coblenz bridgehead were the pontoon bridge and railroad bridge at Coblenz, the railroad bridges at Engers and Remagen. On 13 December the advance began with the American khaki crossing the Rhine into advanced positions. On the same day the 42d Division passes to the command of the IV Corps, which, in support of the III Corps, continued its march to occupy the Kreise of Mayen, Ahrweiler, Adenau, and Cochem. The VII Corps occupied under the order that portion of the Regierungsbezirk of Trier within army limits. On 15 December, Third Army Headquarters at Mayen opened at Coblenz, III Corps Headquarters at Polch opened at Neuwied and IV Corps Headquarters remained at Cochem, with the VII Corps at Grevenmacher. In crossing the Rhine on the shortened front—from Rolandseck to Rhens on the west bank—the Third Army encountered no hostile act of any sort, in the occupied area both food and coal supplies were sufficient. By the night of 14 December, Third Army troops had occupied their positions on the perimeter of the Coblenz bridgehead, during January 1919, the Third Army was engaged in training and preparing the troops under its command for any contingency. A letter of instruction was circulated to lower commanders prescribing a plan of action in case hostilities were resumed, installations were set up throughout the Army area to facilitate command. On 4 February, the control of the Stadtkreis of Trier was transferred from GHQ to the Third Army
Third Army (United States)
–
CFLCC Logo
Third Army (United States)
–
Shoulder sleeve insignia of Third Army
Third Army (United States)
–
"This old castle perched on a hilltop above the Moselle River and the town of Cochem, Germany, is headquarters of the U.S. Fourth Army Corps. In foreground is Cpl. James C. Sulzer, Fourth Army Corps, Photo Unit. January 9, 1919."
Third Army (United States)
–
American flag over
Festung Ehrenbreitstein after the occupation of
Koblenz by the 3rd Army, 1945
35.
Convoy ON-166
–
Convoy ON166 was the 166th of the numbered ON series of merchant ship convoys Outbound from the British Isles to North America. However, only 20 percent of the 180 trans-Atlantic convoys sailing from the end of July 1942 until the end of April 1943 lost ships to U-boat attack, on 20 February U-604 sighted the convoy scattered by sailing eight days in a northwesterly gale. U-332 torpedoed the straggling Norwegian Stigstad on the morning of 21 February, u-623 was sunk by a No.120 Squadron RAF B-24 Liberator that afternoon, and Campbell attacked a U-boat that evening. Postwar analysis concluded that Campbell sank U-225, but more recent re-evaluation indicates the attack may have destroyed U-529, u-92 torpedoed the British Empire Trader at 2032 and the Norwegian NT Nielsen Alonso at 0153 on the night of February 21–22. Both ships were hit by a torpedo on the port side, flooding the forward hold. ORP Burza from the following convoy ONS167 was ordered to reinforce the convoy escort, U-606 torpedoed the British Empire Redshank and American Chattanooga City and Expositor after sunset 22 February, but was damaged by depth charges from the recently arrived Burza. Campbell was disabled in a collision with U-606, twelve men were rescued from the crew of the sinking U-boat. Burza left the convoy to tow Campbell back to port, the convoy rescue ship Stockport was sunk by U-604 while returning to the convoy after rescuing men from the three ships torpedoed by U-606. U-628 torpedoed the Panamanian Winkler at 0420 and Norwegian Glittre at 0425, u-186 torpedoed the American Hastings about 0430 and British Eulima at 0458 on 23 February. Spencer, Rosthern and Chilliwack remained with the convoy and Dianthus left to refuel, u-600 torpedoed the Norwegian Ingria at 0520 before dawn on 24 February. U-653 torpedoed the straggling American Liberty ship Jonathan Sturges, u-628 hit the British Manchester Merchant with two torpedoes on the starboard side at 0527 before dawn 25 February. The U-boats discontinued the attack on 26 February, the surviving ships in the convoy were joined by Empire Cavalier from Halifax, Nova Scotia on 28 February with escorts New Westminster, Blairmore and Rimouski. They reached New York City on 3 March 1943, convoy Battles of World War II Hague, Arnold. History of United States Naval Operations in World War II, Volume I The Battle of the Atlantic 1939-1943, rohwer, J. Hummelchen, G. Chronology of the War at Sea 1939-1945
Convoy ON-166
–
A
depth charge being loaded onto a depth-charge thrower aboard the corvette HMS Dianthus
36.
Merchant ship
–
A merchant vessel or trading vessel is a boat or ship that transports cargo or carries passengers for hire. This excludes pleasure craft that do not carry passengers for hire, most countries of the world operate fleets of merchant ships. However, due to the costs of operations, today these fleets are in many cases sailing under the flags of nations that specialize in providing manpower. Such flags are known as flags of convenience, currently, Liberia and Panama are particularly favoured. Ownership of the vessels can be by any country, however, the Greek-owned fleet is the largest in the world. Today, the Greek fleet accounts for some 16 per cent of the world’s tonnage, during wars, merchant ships may be used as auxiliaries to the navies of their respective countries, and are called upon to deliver military personnel and materiel. The term commercial vessel is defined by the United States Coast Guard as any vessel engaged in trade or that carries passengers for hire. In English, Merchant Navy without further clarification is used to refer to the British Merchant Navy, general cargo ships include multi-purpose and project vessels and roll-on/roll-off cargo. A cargo ship or freighter is any sort of ship or vessel that carries cargo, goods, thousands of cargo carriers ply the worlds seas and oceans each year, they handle the bulk of international trade. Cargo ships are usually designed for the task, often being equipped with cranes and other mechanisms to load and unload. Dry cargo ships today are mainly bulk carriers and container ships, bulk carriers or bulkers are used for the transportation of homogeneous cargo such as coal, rubber, copra, tin, and wheat. Container ships are used for the carriage of miscellaneous goods, a bulk carrier is an ocean-going vessel used to transport bulk cargo items such as iron ore, bauxite, coal, cement, grain and similar cargo. Bulk carriers can be recognized by large box-like hatches on deck, the dimensions of bulk carriers are often determined by the ports and sea routes that they need to serve, and by the maximum width of the Panama Canal. Most lakes are too small to accommodate bulk carriers, but a large fleet of lake freighters has been plying the Great Lakes, container ships are cargo ships that carry all of their load in truck-size containers, in a technique called containerization. They form a common means of commercial freight transport. A tanker is a designed to transport liquids in bulk. Tankers can range in size from several hundred tons, designed to serve small harbours and coastal settlements, to several hundred thousand tons, gas Carriers such as LNG carriers as they are typically known, are a relatively rare tanker designed to carry liquefied natural gas. It has a deadweight of 565 thousand metric tons and length of about 458 meters, the use of such large ships is in fact very unprofitable, due to the inability to operate them at full cargo capacity, hence, the production of supertankers has currently ceased
Merchant ship
–
Historical merchant trading ship: a Dutch
fluyt cargo vessel from the late 17th-century
Merchant ship
–
Sabrina I carries bulk cargo inside her holds.
Merchant ship
–
The
Colombo Express, one of the largest container ships in the world, owned and operated by
Hapag-Lloyd of
Germany
Merchant ship
–
Commercial crude oil
supertanker AbQaiq
37.
British Isles
–
The British Isles are a group of islands off the north-western coast of continental Europe that consist of the islands of Great Britain, Ireland and over six thousand smaller isles. Situated in the North Atlantic, the islands have an area of approximately 315,159 km2. Two sovereign states are located on the islands, Ireland and the United Kingdom of Great Britain, the oldest rocks in the group are in the north west of Scotland, Ireland and North Wales and are 2,700 million years old. During the Silurian period the north-western regions collided with the south-east, the topography of the islands is modest in scale by global standards. Ben Nevis rises to an elevation of only 1,344 metres, and Lough Neagh, the climate is temperate marine, with mild winters and warm summers. The North Atlantic Drift brings significant moisture and raises temperatures 11 °C above the average for the latitude. This led to a landscape which was dominated by temperate rainforest. The region was re-inhabited after the last glacial period of Quaternary glaciation, Ireland, which became an island by 12,000 BC, was not inhabited until after 8000 BC. Great Britain became an island by 5600 BC, Hiberni, Pictish and Britons tribes, all speaking Insular Celtic, inhabited the islands at the beginning of the 1st millennium AD. Much of Brittonic-controlled Britain was conquered by the Roman Empire from AD43, the first Anglo-Saxons arrived as Roman power waned in the 5th century and eventually dominated the bulk of what is now England. Viking invasions began in the 9th century, followed by permanent settlements. Most of Ireland seceded from the United Kingdom after the Irish War of Independence, the term British Isles is controversial in Ireland, where there are objections to its usage due to the association of the word British with Ireland. The Government of Ireland does not recognise or use the term, as a result, Britain and Ireland is used as an alternative description, and Atlantic Archipelago has had limited use among a minority in academia, while British Isles is still commonly employed. Within them, they are sometimes referred to as these islands. The earliest known references to the islands as a group appeared in the writings of sea-farers from the ancient Greek colony of Massalia. The original records have been lost, however, later writings, e. g. Avienuss Ora maritima, in the 1st century BC, Diodorus Siculus has Prettanikē nēsos, the British Island, and Prettanoi, the Britons. Strabo used Βρεττανική, and Marcian of Heraclea, in his Periplus maris exteri, historians today, though not in absolute agreement, largely agree that these Greek and Latin names were probably drawn from native Celtic-language names for the archipelago. Along these lines, the inhabitants of the islands were called the Πρεττανοί, the shift from the P of Pretannia to the B of Britannia by the Romans occurred during the time of Julius Caesar
British Isles
–
Satellite image of the British Isles, excluding
Shetland and the
Channel Islands (out of frame)
British Isles
–
Some female red deer in
Killarney National Park, Ireland.
British Isles
–
The Alfred Jewel (9th century)
British Isles
–
James VI of Scotland (James I of England)
38.
North America
–
North America is a continent entirely within the Northern Hemisphere and almost all within the Western Hemisphere. It can also be considered a subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers, about 16. 5% of the land area. North America is the third largest continent by area, following Asia and Africa, and the fourth by population after Asia, Africa, and Europe. In 2013, its population was estimated at nearly 565 million people in 23 independent states, or about 7. 5% of the worlds population, North America was reached by its first human populations during the last glacial period, via crossing the Bering land bridge. The so-called Paleo-Indian period is taken to have lasted until about 10,000 years ago, the Classic stage spans roughly the 6th to 13th centuries. The Pre-Columbian era ended with the migrations and the arrival of European settlers during the Age of Discovery. Present-day cultural and ethnic patterns reflect different kind of interactions between European colonists, indigenous peoples, African slaves and their descendants, European influences are strongest in the northern parts of the continent while indigenous and African influences are relatively stronger in the south. Because of the history of colonialism, most North Americans speak English, Spanish or French, the Americas are usually accepted as having been named after the Italian explorer Amerigo Vespucci by the German cartographers Martin Waldseemüller and Matthias Ringmann. Vespucci, who explored South America between 1497 and 1502, was the first European to suggest that the Americas were not the East Indies, but a different landmass previously unknown by Europeans. In 1507, Waldseemüller produced a map, in which he placed the word America on the continent of South America. He explained the rationale for the name in the accompanying book Cosmographiae Introductio, for Waldseemüller, no one should object to the naming of the land after its discoverer. He used the Latinized version of Vespuccis name, but in its feminine form America, following the examples of Europa, Asia and Africa. Later, other mapmakers extended the name America to the continent, In 1538. Some argue that the convention is to use the surname for naming discoveries except in the case of royalty, a minutely explored belief that has been advanced is that America was named for a Spanish sailor bearing the ancient Visigothic name of Amairick. Another is that the name is rooted in a Native American language, the term North America maintains various definitions in accordance with location and context. In Canadian English, North America may be used to refer to the United States, alternatively, usage sometimes includes Greenland and Mexico, as well as offshore islands
North America
–
Map of North America, from 1621.
North America
–
North America
North America
–
The
El Castillo pyramid, at
Chichén Itzá, Mexico.
North America
–
Benjamin West 's
The Death of General Wolfe (1771) depicting the
Battle of the Plains of Abraham.
39.
HMM-166
–
Marine Medium Tiltrotor Squadron 166 is a United States Marine Corps tiltrotor squadron consisting of MV-22 Osprey transport aircraft. The squadron, known as the SeaElk, is based at Marine Corps Air Station Miramar, activated in 1985, HMM-166 was the youngest CH-46 helicopter squadron in the Marine Corps. The squadron was redesignated as a squadron on June 23,2010. The squadron was activated on September 13,1985 at Marine Corps Air Station Tustin, California and they relocated during 1995 to Marine Corps Air Station El Toro, California and again during 1999 to MCAS Miramar, California. During this deployment they participated in the Battle of Najaf, on November 5,2007 the squadron deployed to the Western Pacific as the aviation combat element of the 11th Marine Expeditionary Unit. The crash resulted in the fatalities of the two pilots, Jessica Conkling,27, and Aaron Cox,26. The SuperCobra had departed Naval Air Facility El Centro 30–40 minutes earlier for Marine Corps Air Station Miramar, the cause of the crash was an improperly secured transmission cover which came off in flight and struck the tail rotor. In September 2009, HMM-166 again deployed as the combat element of the 11th Marine Expeditionary Unit. They participated in exercises in East Timor, Indonesia, United Arab Emirates, Kuwait and they returned from the deployment in April 2010. The squadron was redesignated as VMM-166 on June 23,2010 and is in the process of transitioning to the MV-22 Osprey, a unit citation or commendation is an award bestowed upon an organization for the action cited. Members of the unit who participated in said actions are allowed to wear on their uniforms the awarded unit citation
HMM-166
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VMM-166 insignia
HMM-166
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Phrog from HMM-166 spreads the ashes of its former CO over
Camp Pendleton in July 2005
HMM-166
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Meritorious Unit Commendation Streamer with one Bronze Star
40.
United States Marine Corps
–
The U. S. Marine Corps is one of the four armed service branches in the U. S. Department of Defense and one of the seven uniformed services of the United States. The current Chairman of the Joint Chiefs of Staff, the military officer in the U. S. Armed Forces, is a Marine Corps general, the Marine Corps has been a component of the U. S. Department of the Navy since 30 June 1834, working closely with naval forces for training, transportation, and logistics. The USMC operates posts on land and aboard sea-going amphibious warfare ships around the world, two battalions of Continental Marines were formed on 10 November 1775 in Philadelphia as a service branch of infantry troops capable of fighting for independence both at sea and on shore. The role of the Corps has since grown and evolved, expanding to aerial warfare and earning popular titles such as, Americas third air force, and, second land army. By the mid-20th century, the U. S. Marine Corps had become a major theorist of and its ability to rapidly respond on short notice to expeditionary crises gives it a strong role in the implementation and execution of American foreign policy. As of 2016, the USMC has around 182,000 active duty members and it is the smallest of the U. S. The USMC serves as an expeditionary force-in-readiness and this last clause, while seemingly redundant given the Presidents position as Commander-in-chief, is a codification of the expeditionary responsibilities of the Marine Corps. It derives from similar language in the Congressional acts For the Better Organization of the Marine Corps of 1834, in 1951, the House of Representatives Armed Services Committee called the clause one of the most important statutory – and traditional – functions of the Marine Corps. In addition to its duties, the Marine Corps conducts Visit, Board, Search, and Seizure operations, as well as missions in direct support of the White House. The Marine Band, dubbed the Presidents Own by Thomas Jefferson, Marines from Ceremonial Companies A & B, quartered in Marine Barracks, Washington, D. C. The Executive Flight Detachment also provides transport to Cabinet members. The relationship between the Department of State and the U. S. Marine Corps is nearly as old as the corps itself, for over 200 years, Marines have served at the request of various Secretaries of State. After World War II, an alert, disciplined force was needed to protect American embassies, consulates, in 1947, a proposal was made that the Department of War furnish Marine Corps personnel for Foreign Service guard duty under the provisions of the Foreign Service Act of 1946. A formal Memorandum of Agreement was signed between the Department of State and the Secretary of the Navy on December 15,1948, during the first year of the MSG program,36 detachments were deployed worldwide. Continental Marines manned raiding parties, both at sea and ashore, the Advanced Base Doctrine of the early 20th century codified their combat duties ashore, outlining the use of Marines in the seizure of bases and other duties on land to support naval campaigns. Throughout the late 19th and 20th centuries, Marine detachments served aboard Navy cruisers, battleships, Marine detachments served in their traditional duties as a ships landing force, manning the ships weapons and providing shipboard security. Marines would develop tactics and techniques of amphibious assault on defended coastlines in time for use in World War II, during World War II, Marines continued to serve on capital ships
United States Marine Corps
United States Marine Corps
–
United States Marine Corps portal
United States Marine Corps
United States Marine Corps
–
A Marine
Corporal and
Lance Corporal of
3rd Battalion, 6th Marines engaging the enemy during
Operation Moshtarak in Afghanistan's
Helmand Province.
41.
Helicopter
–
A helicopter is a type of rotorcraft in which lift and thrust are supplied by rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and these attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft and many forms of VTOL aircraft cannot perform. English language nicknames for helicopter include chopper, copter, helo, heli, Helicopters were developed and built during the first half-century of flight, with the Focke-Wulf Fw 61 being the first operational helicopter in 1936. Some helicopters reached limited production, but it was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production, with 131 aircraft built. Though most earlier designs used more than one rotor, it is the single main rotor with anti-torque tail rotor configuration that has become the most common helicopter configuration. Tandem rotor helicopters are also in use due to their greater payload capacity. Coaxial helicopters, tiltrotor aircraft, and compound helicopters are all flying today, quadcopter helicopters pioneered as early as 1907 in France, and other types of multicopter have been developed for specialized applications such as unmanned drones. The earliest references for vertical flight came from China, since around 400 BC, Chinese children have played with bamboo flying toys. This bamboo-copter is spun by rolling a stick attached to a rotor, the spinning creates lift, and the toy flies when released. The 4th-century AD Daoist book Baopuzi by Ge Hong reportedly describes some of the ideas inherent to rotary wing aircraft, designs similar to the Chinese helicopter toy appeared in Renaissance paintings and other works. In the 18th and early 19th centuries Western scientists developed flying machines based on the Chinese toy. It was not until the early 1480s, when Leonardo da Vinci created a design for a machine that could be described as an aerial screw, that any recorded advancement was made towards vertical flight. His notes suggested that he built flying models, but there were no indications for any provision to stop the rotor from making the craft rotate. As scientific knowledge increased and became accepted, people continued to pursue the idea of vertical flight. In July 1754, Russian Mikhail Lomonosov had developed a small coaxial modeled after the Chinese top but powered by a spring device. It was powered by a spring, and was suggested as a method to lift meteorological instruments. Sir George Cayley, influenced by a fascination with the Chinese flying top, developed a model of feathers, similar to that of Launoy and Bienvenu. By the end of the century, he had progressed to using sheets of tin for rotor blades and his writings on his experiments and models would become influential on future aviation pioneers
Helicopter
–
A police department
Bell 206 helicopter
Helicopter
–
A decorated Japanese taketombo bamboo-copter
Helicopter
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Leonardo's "aerial screw"
Helicopter
–
Prototype created by
M. Lomonosov, 1754
42.
USCGC Tamaroa (WMEC-166)
–
USCGC Tamaroa was a United States Coast Guard cutter, originally the United States Navy Cherokee-class fleet tug USS Zuni. Following the USCG custom of naming cutters in this class of ship after Native American tribes and she was one of 70 built in her class for the US Navy. She saw action in World War II, including the Marianas, Philippines, after the war she was transferred to the USCG. She was involved in the tort case, Ira S. Bushey & Sons. An employer will be liable under respondeat superior if the actions of the employee arise out of the course of his employment. Held, the ship is liable for anything ship-connected persons cause it to do, the bulk of her USCG career was spent patrolling, working in drug interdiction, and fisheries protection. She was the first Coast Guard Cutter to arrive at the sinking Andrea Doria. She is perhaps most famous for a rescue described in the book The Perfect Storm, after she was decommissioned from the USCG, she was donated to the Intrepid Sea-Air-Space Museum in New York City. She was noticed tied up next to the Intrepid in 1994 by a crewman who began a campaign to restore her. The foundation attempted to preserve the ship in an operational condition and she is currently sitting in Norfolk, VA, waiting to be environmentally cleaned, scuttled and turned into an artificial reef. org, USCGC Tamaroa
USCGC Tamaroa (WMEC-166)
–
USCGC Tamaroa (WMEC-166) in 1990, formerly USS Zuni (ATF-95).
43.
United States Coast Guard
–
The United States Coast Guard is a branch of the United States Armed Forces and one of the countrys seven uniformed services. This has happened twice, in 1917, during World War I, created by Congress on 4 August 1790 at the request of Alexander Hamilton as the Revenue Marine, it is the oldest continuous seagoing service of the United States. As Secretary of the Treasury, Hamilton headed the Revenue Marine, by the 1860s, the service was known as the U. S. Revenue Cutter Service and the term Revenue Marine gradually fell into disuse, the modern Coast Guard was formed by a merger of the Revenue Cutter Service and the U. S. Life-Saving Service on 28 January 1915, under the U. S. Department of the Treasury. As one of the five armed services, the Coast Guard has been involved in every U. S. war from 1790 to the Iraq War. As of 2014 the Coast Guard had over 36,000 men and women on duty,7,350 reservists,29,620 auxiliarists. In terms of size, the U. S. Coast Guard by itself is the worlds 12th largest naval force. Because of its authority, the Coast Guard can conduct military operations under the U. S. Department of Defense or directly for the President in accordance with Title 14 USC 1–3. The Coast Guards enduring roles are maritime safety, security, to carry out those roles, it has 11 statutory missions as defined in 6 U. S. C. §468, which include enforcing U. S. law in the worlds largest exclusive economic zone of 3.4 million square miles, the Coast Guards motto is the Latin phrase, Semper Paratus. In a 2005 article in Time magazine following Hurricane Katrina, the author wrote, the Coast Guards most valuable contribution to may be as a model of flexibility, and most of all, spirit. Wil Milam, a swimmer from Alaska told the magazine, In the Navy. Practicing for war, training for war, in the Coast Guard, it was, take care of our people and the mission will take care of itself. The Coast Guard carries out three basic roles, which are subdivided into eleven statutory missions. Both agencies maintain rescue coordination centers to coordinate this effort, and have responsibility for military and civilian search and rescue. The two services jointly provide instructor staff for the National Search and Rescue School that trains SAR mission planners and coordinators, previously located on Governors Island, New York, the school is now located at Coast Guard Training Center Yorktown at Yorktown, Virginia. The NRC also takes Maritime Suspicious Activity and Security Breach Reports, details on the NRC organization and specific responsibilities can be found in the National Oil and Hazardous Substances Pollution Contingency Plan. The Marine Information for Safety and Law Enforcement database system is managed and used by the Coast Guard for tracking pollution, the five uniformed services that make up the U. S
United States Coast Guard
–
A boatswain's mate watches from the side port door as
Coast Guard Cutter Bertholf's Over-The-Horizon small boat departs to receive personnel from Coast Guard Cutter Chandeleur in 2008.
United States Coast Guard
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The official seal of the United States Coast Guard, adopted in December 1966.
United States Coast Guard
–
A Coast Guard
Aviation Survival Technician assisting with the rescue of a pregnant woman during
Hurricane Katrina.
United States Coast Guard
–
Search and Rescue Program Logo of the United States Coast Guard.
44.
Cutter (ship)
–
A cutter is typically a small, but in some cases a medium-sized, watercraft designed for speed rather than for capacity. Traditionally a cutter sailing vessel is a small single-masted boat, fore-and-aft rigged, the cutters mast may be set farther back than on a sloop. In modern usage, a cutter can be either a small- or medium-sized vessel whose occupants exercise official authority, examples are harbor pilots cutters and cutters of the U. S. Coast Guard or UK Border Force. Cutters can also be a small boat serving a one to ferry passengers or light stores between larger boats and the shore. This type of cutter may be powered by oars, sails or a motor, the cutter is one of several types of sailboats. Traditionally the sloop rig was a rig with a single mast located forward of 70% of the length of the sailplan, in this traditional definition a sloop could have multiple jibs on a fixed bowsprit. Cutters had a rig with a single mast more centrally located, which could vary from 50% to 70% of the length of the sailplan, with multiple headsails, a mast located aft of 50% would be considered a mast aft rig. Somewhere in the 1950s or 1960s there was a shift in these definitions such that a sloop only flew one headsail, in this modern idiom, a cutter is a sailing vessel with more than one head sail and one mast. Cutters carry a staysail directly in front of the mast, set from the forestay, a traditional vessel would also normally have a bowsprit to carry one or more jibs from its end via jibstay on travelers. In modern vessels the jib may be set from a permanent stay fixed to the end of a fixed bowsprit, or directly to the stem fitting of the bow itself. In these cases, that may be referred to as the forestay, and the inner one, a sloop carries only one head sail, called either the foresail or jib. These could be managed without the need for crews, winches, or complex tackles, making the cutter especially suitable for pilot, customs. For example, a pilot cutter may only have two people on board for its outward trip—the pilot to be delivered to a ship and an assistant who had to sail the cutter back to port single-handed. The cutter sailing rig became so ubiquitous for these tasks that the modern-day motorised vessels now engaged in these duties are known as cutters, the open cutter carried aboard naval vessels in the 18th Century was rowed by pairs of men sitting side-by-side on benches. The cutter, with its transom, was broader in proportion compared to the longboat, the Watermen of London used similar boats in the 18th Century often decorated as depicted in historical prints and pictures of the River Thames in the 17th & 18th Centuries. The modern Waterman’s Cutter is based on drawings of these boats and they are 34 feet long with a beam of 4 ft 6 in They can have up to six oarsmen either rowing or sculling and can carry a cox and passengers. The organisers of the Great River Race developed the modern version in the 1980s, watermen’s Cutters also compete annually in the Port of London Challenge, and the Port Admirals’ Challenge. Cutter races are also to be found at various town rowing and skiffing regattas, in addition the cutters perform the role of ceremonial Livery Barges with the canopies and armorial flags flying on special occasions
Cutter (ship)
–
A gaff cutter, Kleine Freiheit, with a
genoa jib set
Cutter (ship)
–
French cutter
Cutter (ship)
–
1/50-scale Model of the 14-
carronade cutters that were in service in the
French Navy during the 1830s.
Cutter (ship)
–
Cutter race at
Sunbury Amateur Regatta
45.
USS Alcedo (SP-166)
–
USS Alcedo was a yacht in the United States Navy. She was the first American vessel lost in World War I, Alcedo was built in 1895 at Glasgow, Scotland, by D. and W. Henderson and Company. She was purchased by the Navy on 1 June 1917 from Mr. George W. C, drexel of Philadelphia, Pennsylvania, and commissioned at New York City on 28 July 1917, Lieutenant Commander William T. Conn, Jr. in command. Assigned to the Patrol Force, Alcedo departed Newport, Rhode Island on 5 August 1917, steaming via Newfoundland and the Azores, the yacht arrived at Brest, France on the 30th. During her brief Navy career, the yacht conducted anti-submarine patrols, on two occasions, she rescued crew members of torpedoed merchantmen. On 17 October, the little warship picked up 118 men from the troop transport steamer SS Antilles, twelve days later, she saved another 85 survivors from SS Finland. At about 01,45 the following morning, while the convoy was steaming some 75 mi west of Belle He, almost instantaneously with the sounding of the alarm, the German submarine UC-71 fired a single torpedo in a surface attack. Alcedo attempted to change course to evade the torpedo, but she answered her helm sluggishly, the torpedo struck the yacht on the port side well forward, and Alcedo began to settle fast. Soon after the hit, the commanding officer ordered her abandoned. The yacht lost one officer, Lieutenant, junior grade John Melvin, the remainder of her crew took to the boats in two separate groups. After a long time rowing, one group — which included the commanding officer — was picked up by a French torpedo boat, the other was towed to safety by French fishermen. Alcedos name was struck from the Naval Vessel Register on 17 December 1917 and this article incorporates text from the public domain Dictionary of American Naval Fighting Ships. The entry can be found here, photo gallery of USS Alcedo at NavSource Naval History
USS Alcedo (SP-166)
–
USS Alcedo
46.
United States Navy
–
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U. S. Navy is the largest, most capable navy in the world, the U. S. Navy has the worlds largest aircraft carrier fleet, with ten in service, two in the reserve fleet, and three new carriers under construction. The service has 323,792 personnel on duty and 108,515 in the Navy Reserve. It has 274 deployable combat vessels and more than 3,700 operational aircraft as of October 2016, the U. S. Navy traces its origins to the Continental Navy, which was established during the American Revolutionary War and was effectively disbanded as a separate entity shortly thereafter. It played a role in the American Civil War by blockading the Confederacy. It played the role in the World War II defeat of Imperial Japan. The 21st century U. S. Navy maintains a global presence, deploying in strength in such areas as the Western Pacific, the Mediterranean. The Navy is administratively managed by the Department of the Navy, the Department of the Navy is itself a division of the Department of Defense, which is headed by the Secretary of Defense. The Chief of Naval Operations is an admiral and the senior naval officer of the Department of the Navy. The CNO may not be the highest ranking officer in the armed forces if the Chairman or the Vice Chairman of the Joint Chiefs of Staff. The mission of the Navy is to maintain, train and equip combat-ready Naval forces capable of winning wars, deterring aggression, the United States Navy is a seaborne branch of the military of the United States. The Navys three primary areas of responsibility, The preparation of naval forces necessary for the prosecution of war. The development of aircraft, weapons, tactics, technique, organization, U. S. Navy training manuals state that the mission of the U. S. Armed Forces is to prepare and conduct prompt and sustained combat operations in support of the national interest, as part of that establishment, the U. S. Navys functions comprise sea control, power projection and nuclear deterrence, in addition to sealift duties. It follows then as certain as that night succeeds the day, that without a decisive naval force we can do nothing definitive, the Navy was rooted in the colonial seafaring tradition, which produced a large community of sailors, captains, and shipbuilders. In the early stages of the American Revolutionary War, Massachusetts had its own Massachusetts Naval Militia, the establishment of a national navy was an issue of debate among the members of the Second Continental Congress. Supporters argued that a navy would protect shipping, defend the coast, detractors countered that challenging the British Royal Navy, then the worlds preeminent naval power, was a foolish undertaking. Commander in Chief George Washington resolved the debate when he commissioned the ocean-going schooner USS Hannah to interdict British merchant ships, and reported the captures to the Congress
United States Navy
United States Navy
–
United States Navy portal
United States Navy
–
USS Constellation vs L'Insurgente during the
Quasi-War
United States Navy
–
USS Constitution vs HMS Guerriere during the
War of 1812
47.
Yacht
–
A yacht /ˈjɒt/ is a recreational boat or ship. In modern use of the term, yachts differ from working ships mainly by their leisure purpose, there are two different classes of yachts, sailing and power boats. With the rise of the steamboat and other types of powerboat, sailing vessels in general came to be perceived as luxury, later the term came to encompass large motor boats for primarily private pleasure purposes as well. Yacht lengths normally range from 10 metres up to dozens of meters, a luxury craft smaller than 12 metres is more commonly called a cabin cruiser or simply a cruiser. A superyacht generally refers to any yacht above 24 m and a megayacht generally refers to any yacht over 50 metres and this size is small in relation to typical cruise liners and oil tankers. A few countries have a special flag worn by recreational boats or ships, although inspired by the national flag, the yacht ensign does not always correspond with the civil or merchant ensign of the state in question. Yacht ensigns differ from merchant ensigns in order to signal that the yacht is not carrying cargo that requires a customs declaration, carrying commercial cargo on a boat with a yacht ensign is deemed to be smuggling in many jurisdictions. Until the 1950s, almost all yachts were made of wood or steel, although wood hulls are still in production, the most common construction material is fibreglass, followed by aluminium, steel, carbon fibre, and ferrocement. The use of wood has changed and is no longer limited to traditional board-based methods, wood is mostly used by hobbyists or wooden boat purists when building an individual boat. Apart from materials like carbon fibre and aramid fibre, spruce veneers laminated with epoxy resins have the best weight-to-strength ratios of all boatbuilding materials. Sailing yachts can range in length from about 6 metres to well over 30 metres. Most privately owned yachts fall in the range of about 7 metres -14 metres, in the United States, sailors tend to refer to smaller yachts as sailboats, while referring to the general sport of sailing as yachting. Within the limited context of racing, a yacht is any sailing vessel taking part in a race. Many modern racing yachts have efficient sail-plans, most notably the Bermuda rig. This capability is the result of a sail-plan and hull design oriented towards this capability, day sailing yachts are usually small, at under 6 metres in length. Sometimes called sailing dinghies, they often have a keel, centreboard. Most day sailing yachts do not have a cabin, as they are designed for hourly or daily use and not for overnight journeys. They may have a cabin, where the front part of the hull has a raised solid roof to provide a place to store equipment or to offer shelter from wind or spray
Yacht
–
Sailing Yacht "Zapata II"
Yacht
–
The "Lazzara" 80' "Alchemist" runs at full speed up the California Coast
Yacht
–
A yacht in
Lorient,
Brittany,
France
Yacht
–
Aerial view of a
yacht club and
marina - Yacht Harbour Residence "Hohe Düne" in
Rostock,
Germany.
48.
Destroyer escort
–
Destroyer escort was the United States Navy mid-20th century classification for a 20-knot warship designed with endurance to escort mid-ocean convoys of merchant marine ships. Kaibōkan were designed for a role in the Imperial Japanese Navy. The Royal Navy and Commonwealth forces identified such warships as frigates, Destroyer escorts, frigates and kaibōkan were mass-produced for World War II as a less expensive anti-submarine warfare alternative to fleet destroyers. Post-war destroyer escorts and frigates were larger than those produced during wartime, with increased anti-aircraft capability, as Cold War destroyer escorts became as large as wartime destroyers, the United States Navy converted some of their World War II destroyers to escort destroyers. Full-size destroyers must be able to steam as fast or faster than the fast capital ships such as carriers and cruisers. This typically requires a speed of 25–35 knots and they must carry torpedoes and a smaller caliber of cannon to use against enemy ships, as well as anti-submarine detection equipment and weapons. A destroyer escort needed only to be able to maneuver relative to a slow convoy and these lower requirements greatly reduce the size, cost, and crew required for the destroyer escort. Destroyer escorts were optimized for anti-submarine warfare, having a turning radius. Their much slower speed was not a liability in this context, Destroyer escorts were also considerably more sea-kindly than corvettes. Electric drive was selected because it does not need gearboxes to adjust engine speed to the much lower optimum speed for the propellers, Destroyer escorts were also useful for coastal anti-submarine and radar picket ship duty. During World War II, seven destroyer escorts were converted to radar picket destroyer escorts, although these were relegated to secondary roles after the war, in the mid-1950s twelve more DEs were converted to DERs, serving as such until 1960-1965. Their mission was to extend the Distant Early Warning line on coasts, in conjunction with sixteen Guardian-class radar picket ships, which were converted Liberty ships. In World War II, some 95 destroyer escorts were converted by the US to high-speed transports and this involved adding an extra deck which allowed space for about 10 officers and 150 men. Two large davits were installed, one on either side of the ship. This enabled the UK to commission the US to design, build and supply an escort vessel that was suitable for anti-submarine warfare in deep open ocean situations, cochrane of the American Bureau of Shipping came up with a design which was known as the British Destroyer Escort. S. Navy and one to the Royal Navy, after World War II United States Navy destroyer escorts were referred to as ocean escorts, but retained the hull classification symbol DE. However other navies, most notably those of NATO countries and the USSR, in order to remedy this problem the 1975 ship reclassification reclassified ocean escorts as frigates. This brought the USNs nomenclature more in line with NATO, as of 2006 there are no plans for future frigates for the US Navy
Destroyer escort
–
USS Evarts (DE-5), an example of the Evarts subclass.
Destroyer escort
–
USS Dealey (DE-1006)
Destroyer escort
–
HMS Dacres, converted to act as a headquarters ship during
Operation Neptune
49.
USS Bush (DD-166)
–
USS Bush was a Wickes-class destroyer built for the United States Navy during World War I. The Wickes class was an improved and faster version of the preceding Caldwell-class, two different designs were prepared to the same specification that mainly differed in the turbines and boilers used. The ships displaced 1, 202–1,208 long tons at load and 1. They had a length of 314 feet 4 inches, a beam of 30 feet 11 inches. They had a crew of 6 officers and 108 enlisted men, performance differed radically between the ships of the class, often due to poor workmanship. The Wickes class was powered by two turbines, each driving one propeller shaft, using steam provided by four water-tube boilers. The turbines were designed to produce a total of 27,000 shaft horsepower intended to reach a speed of 35 knots, the ships carried 225 long tons of fuel oil which was intended gave them a range of 2,500 nautical miles at 20 knots. The ships were armed with four 4-inch guns in single mounts and were fitted with two 1-pdr guns for anti-aircraft defense and their primary weapon, though, was their torpedo battery of a dozen 21-inch torpedo tubes in four triple mounts. In many ships a shortage of 1-pounders caused them to be replaced by 3-inch anti-aircraft guns and they also carried a pair of depth charge rails. A Y-gun depth charge thrower was added to many ships and she was in reserve status until the summer of 1920. She then engaged in conducting training cruises for Naval Reserves, thereafter, she exercised alternately at Charleston, her winter base, and at Newport, Rhode Island, her summer base, until placed out of commission 21 June 1922 at Philadelphia Navy Yard. Bush was sold 8 September 1936, U. S. Destroyers, An Illustrated Design History. Gardiner, Robert & Gray, Randal, eds, conways All the Worlds Fighting Ships, 1906–1921. This article incorporates text from the public domain Dictionary of American Naval Fighting Ships, the entry can be found here
USS Bush (DD-166)
–
History