The Wright brothers and Wilbur, were two American aviation pioneers credited with inventing and flying the world's first successful airplane. They made the first controlled, sustained flight of a powered, heavier-than-air aircraft with the Wright Flyer on December 17, 1903, four miles south of Kitty Hawk, North Carolina. In 1904–05, the brothers developed their flying machine into the first practical fixed-wing aircraft, the Wright Flyer III. Although not the first to build experimental aircraft, the Wright brothers were the first to invent aircraft controls that made fixed-wing powered flight possible; the brothers' breakthrough was their creation of a three-axis control system, which enabled the pilot to steer the aircraft and to maintain its equilibrium. This method remains standard on fixed-wing aircraft of all kinds. From the beginning of their aeronautical work, the Wright brothers focused on developing a reliable method of pilot control as the key to solving "the flying problem"; this approach differed from other experimenters of the time who put more emphasis on developing powerful engines.
Using a small homebuilt wind tunnel, the Wrights collected more accurate data than any before, enabling them to design more efficient wings and propellers. Their first U. S. patent did not claim invention of a flying machine, but a system of aerodynamic control that manipulated a flying machine's surfaces. The brothers gained the mechanical skills essential to their success by working for years in their Dayton, Ohio-based shop with printing presses, bicycles and other machinery, their work with bicycles in particular influenced their belief that an unstable vehicle such as a flying machine could be controlled and balanced with practice. From 1900 until their first powered flights in late 1903, they conducted extensive glider tests that developed their skills as pilots, their shop employee Charlie Taylor became an important part of the team, building their first airplane engine in close collaboration with the brothers. The Wright brothers' status as inventors of the airplane has been subject to counter-claims by various parties.
Much controversy persists over the many competing claims of early aviators. Edward Roach, historian for the Dayton Aviation Heritage National Historical Park, argues that they were excellent self-taught engineers who could run a small company, but they did not have the business skills or temperament to dominate the growing aviation industry; the Wright brothers were two of seven children born to Milton Wright, of English and Dutch ancestry, Susan Catherine Koerner, of German and Swiss ancestry. Milton Wright's mother, Catherine Reeder, was descended from the progenitor of the Vanderbilt family and the Huguenot Gano family of New Rochelle, New York. Wilbur was born near Millville, Indiana, in 1867; the brothers never married. The other Wright siblings were Reuchlin, Lorin and twins Otis and Ida; the direct paternal ancestry goes back to a Samuel Wright who sailed to America and settled in Massachusetts in 1636. None of the Wright children had middle names. Instead, their father tried hard to give them distinctive first names.
Wilbur was named for Wilbur Fisk and Orville for Orville Dewey, both clergymen that Milton Wright admired. They were "Will" and "Orv" to their friends and in Dayton, their neighbors knew them as "the Bishop's kids", or "the Bishop's boys"; because of their father's position as a bishop in the Church of the United Brethren in Christ, he traveled and the Wrights moved — twelve times before returning permanently to Dayton in 1884. In elementary school, Orville was once expelled. In 1878 when the family lived in Cedar Rapids, their father brought home a toy helicopter for his two younger sons; the device was based on an invention of French aeronautical pioneer Alphonse Pénaud. Made of paper and cork with a rubber band to twirl its rotor, it was about a foot long. Wilbur and Orville played with it until it broke, built their own. In years, they pointed to their experience with the toy as the spark of their interest in flying. Both brothers did not receive diplomas; the family's abrupt move in 1884 from Richmond, Indiana, to Dayton, where the family had lived during the 1870s, prevented Wilbur from receiving his diploma after finishing four years of high school.
The diploma was awarded posthumously to Wilbur on April 16, 1994, which would have been his 127th birthday. In late 1885 or early 1886 Wilbur was struck in the face by a hockey stick while playing an ice-skating game with friends, resulting in the loss of his front teeth, he had been vigorous and athletic until and although his injuries did not appear severe, he became withdrawn. He had planned to attend Yale. Instead, he spent the next few years housebound. During this time he cared for his mother, terminally ill with tuberculosis, read extensively in his father's library and ably assisted his father during times of controversy within the Brethren Church, but expressed unease over his own lack of ambition. Orville dropped out of high school after his junior year to start a printing business in 1889, having designed and built his own printing press with Wilbur's help. Wilbur joined the print shop, in March the brothers launched a weekly newspaper, the West Side News. Subsequent issues listed Orville as Wilbur as editor on the masthead.
In April 1890 they converted the paper to a daily, The Evening Item, but it lasted only f
2000 Library of Congress bimetallic ten dollar coin
The 2000 Library of Congress bimetallic ten-dollar coin is a modern U. S. commemorative coin issued in a ten dollar denomination. It is the first platinum bimetallic coin to be issued by the United States Mint, it was issued in business strike qualities. The issue price was $405 for the uncirculated version; the bimetallic coin design was inspired by the graceful architecture of the library's Jefferson Building. The outer ring is stamped from a sheet of gold a solid core of platinum is placed within the ring; the gold ring and platinum core are stamped forming an annular bead where the two precious metals meet. The obverse depicts the hand of Minerva, the Goddess of Wisdom, raising the torch of learning aside the dome of the Thomas Jefferson Building; the coin's reverse is marked with the Library of Congress seal encircled by a laurel wreath, symbolizing its national accomplishment. Mintage: 200,000; the final mintages were 6,683 uncirculated, 27,652 proof. U. S. Mint Facility: West Point, NY Public Law: 105-268 Modern United States commemorative coins Original press release US Mint Special Programs page US Mint Coin Library
In science and engineering, the weight of an object is related to the amount of force acting on the object, either due to gravity or to a reaction force that holds it in place. Some standard textbooks define weight as a vector quantity, the gravitational force acting on the object. Others define weight as the magnitude of the gravitational force. Others define it as the magnitude of the reaction force exerted on a body by mechanisms that keep it in place: the weight is the quantity, measured by, for example, a spring scale. Thus, in a state of free fall, the weight would be zero. In this sense of weight, terrestrial objects can be weightless: ignoring air resistance, the famous apple falling from the tree, on its way to meet the ground near Isaac Newton, would be weightless; the unit of measurement for weight is that of force, which in the International System of Units is the newton. For example, an object with a mass of one kilogram has a weight of about 9.8 newtons on the surface of the Earth, about one-sixth as much on the Moon.
Although weight and mass are scientifically distinct quantities, the terms are confused with each other in everyday use. Further complications in elucidating the various concepts of weight have to do with the theory of relativity according to which gravity is modelled as a consequence of the curvature of spacetime. In the teaching community, a considerable debate has existed for over half a century on how to define weight for their students; the current situation is that a multiple set of concepts co-exist and find use in their various contexts. Discussion of the concepts of heaviness and lightness date back to the ancient Greek philosophers; these were viewed as inherent properties of objects. Plato described weight as the natural tendency of objects to seek their kin. To Aristotle and levity represented the tendency to restore the natural order of the basic elements: air, earth and water, he ascribed absolute weight to earth and absolute levity to fire. Archimedes saw weight as a quality opposed to buoyancy, with the conflict between the two determining if an object sinks or floats.
The first operational definition of weight was given by Euclid, who defined weight as: "weight is the heaviness or lightness of one thing, compared to another, as measured by a balance." Operational balances had, been around much longer. According to Aristotle, weight was the direct cause of the falling motion of an object, the speed of the falling object was supposed to be directly proportionate to the weight of the object; as medieval scholars discovered that in practice the speed of a falling object increased with time, this prompted a change to the concept of weight to maintain this cause effect relationship. Weight was split into a "still weight" or pondus, which remained constant, the actual gravity or gravitas, which changed as the object fell; the concept of gravitas was replaced by Jean Buridan's impetus, a precursor to momentum. The rise of the Copernican view of the world led to the resurgence of the Platonic idea that like objects attract but in the context of heavenly bodies. In the 17th century, Galileo made significant advances in the concept of weight.
He proposed a way to measure the difference between the weight of a moving object and an object at rest. He concluded weight was proportionate to the amount of matter of an object, not the speed of motion as supposed by the Aristotelean view of physics; the introduction of Newton's laws of motion and the development of Newton's law of universal gravitation led to considerable further development of the concept of weight. Weight became fundamentally separate from mass. Mass was identified as a fundamental property of objects connected to their inertia, while weight became identified with the force of gravity on an object and therefore dependent on the context of the object. In particular, Newton considered weight to be relative to another object causing the gravitational pull, e.g. the weight of the Earth towards the Sun. Newton considered space to be absolute; this allowed him to consider concepts as true velocity. Newton recognized that weight as measured by the action of weighing was affected by environmental factors such as buoyancy.
He considered this a false weight induced by imperfect measurement conditions, for which he introduced the term apparent weight as compared to the true weight defined by gravity. Although Newtonian physics made a clear distinction between weight and mass, the term weight continued to be used when people meant mass; this led the 3rd General Conference on Weights and Measures of 1901 to declare "The word weight denotes a quantity of the same nature as a force: the weight of a body is the product of its mass and the acceleration due to gravity", thus distinguishing it from mass for official usage. In the 20th century, the Newtonian concepts of absolute time and space were challenged by relativity. Einstein's equivalence principle put all observers, accelerating, on the same footing; this led to an ambiguity as to what is meant by the force of gravity and weight. A scale in an accelerating elevator cannot be distinguished from a scale in a gravitational field. Gravitational force and weight thereby became frame-dependent quantities.
This prompted the abandonment of the concept as superfluous in the fundamental sciences such as physics and chemistry. Nonetheless, the concept remained important in the teaching of physics; the ambiguities introduced by relativity led, starting in the 1960s, to considerable debate in the teaching community as how to define weight for their s
A double eagle is a gold coin of the United States with a denomination of $20. The coins are made from a 90% gold and 10% copper alloy and have a total weight of 1.0750 troy ounces. The "eagle", "half eagle", "quarter eagle" were given these names in the Act of Congress that authorized them; the double eagle was created as such by name in the Coinage Act of 1849. Prior to 1850, eagles with a denomination of $10 were the largest denomination of US coin; the $10 eagles were produced beginning in 1795, just two years after the first U. S. mint opened. Since the $20 gold piece had twice the value of the eagle, these coins were designated "double eagles"; the first double eagle was minted in 1849. In that year, the mint produced two pieces in proof; the first resides in the Smithsonian Institution in Washington, D. C.. The second was presented to Treasury Secretary William M. Meredith and was sold as part of his estate—the present location of this coin remains unknown. In 1904, President Theodore Roosevelt sought to beautify American coinage, proposed Augustus Saint-Gaudens as an artist capable of the task.
Although the sculptor had poor experiences with the Mint and its chief engraver, Charles E. Barber, Saint-Gaudens accepted Roosevelt's call; the work was subject to considerable delays, due to Saint-Gaudens's declining health and difficulties because of the high relief of his design. Saint-Gaudens died in 1907, after designing the eagle and double eagle, but before the designs were finalized for production; the new coin became known as the Saint-Gaudens double eagle. Regular production continued until 1933, when the official price of gold was changed to $35/oz by the Gold Reserve Act; the 1933 double eagle is among the most valuable of U. S. coins, with the sole example known to be in private hands selling in 2002 for $7,590,020. Regular issue double eagles come in two major types and six minor varieties as follows: Liberty head 1849–1907 Liberty head, no motto, value "twenty D." 1849–1866 Liberty head, with motto, value "twenty D." 1866–1876 Liberty head, with motto, value "twenty dollars" 1877–1907 Saint Gaudens' 1907–1933 Saint Gaudens', high relief, Roman numerals, no motto 1907 Saint Gaudens', low relief, Arabic numerals, no motto 1907–1908 Saint Gaudens', low relief, Arabic numerals, with motto 1908–1933 Due to the less desirable artwork and therefore lower demand, liberty coronet $20 gold pieces are less encountered, the common subtype commands less than the St.-Gaudens' type.
In 1866, the motto "In God We Trust" was added to the liberty coronet double eagle, creating a second subtype. In 1877, the coin's denomination design on the reverse was changed from "twenty D" to "twenty dollars" creating a third and final subtype for the series. An 1879 pattern coin was made for the quintuple stella using a design combining features of the liberty head double eagle and stella pattern coin and using the same alloy as the stella; however this coin was stolen in July 2008. The Saint-Gaudens double eagle is named for the designer, Augustus Saint-Gaudens, one of the premier sculptors in American history. Theodore Roosevelt imposed upon him in his last few years to redesign the nation's coinage at the beginning of the 20th century. Saint-Gaudens' work on the high-relief $20 gold piece is considered to be one of the most extraordinary pieces of art on any American coin; the mint insisted on a low-relief version, as the high-relief coin took up to eleven strikes to bring up the details and did not stack for banking purposes.
Only 12,367 of these coins were struck in 1907. These coins top the $10,000 price in circulated grades, but can reach nearly a half million dollars in the best states of preservation. There were several changes in the early years of this design; the first coins issued in 1907 design featured a date in Roman numerals, but this was changed that year to the more convenient Arabic numerals. The motto "In God We Trust" was omitted from the initial design, as Roosevelt felt that putting the name of God on money that could be used for immoral purposes was inappropriate. By act of Congress, the motto was added in mid-1908; the design of the Saint-Gaudens coin was changed once more when New Mexico and Arizona became states in 1912, the number of stars along the rim was accordingly increased from 46 to 48. Double eagles were minted through 1933, although few of the last years' coinages were released before the gold recall legislation of that year. Accordingly, these issues bring high prices; the Saint-Gaudens obverse design was reused in the American eagle gold bullion coins that were instituted in 1986.
The early 1907 double eagles and the 1986-1991 gold American eagles are the only instances of Roman numerals denoting the date on American coinage. On January 22, 2009, the U. S. Mint released ultra-high relief double eagles using the deep design that Saint-Gaudens envisioned, so that the U. S. Mint could, as its web site states "fulfill Augustus Saint-Gaudens' vision of an ultra high relief coin that could not be realized in 1907 with his legendary Double Eagle liberty design." Despite that claim, the mint reaffirmed just what doomed the first attempts in 1907. The coin's abradable 0.9999 fine gol
The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre. One millimetre is equal to 1000000 nanometres. A millimetre is equal to 5⁄127 of an inch. Since 1983, the metre has been defined as "the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second". A millimetre, 1/1000 of a metre, is therefore the distance travelled by light in 1/299792458000 of a second. A common shortening of millimetre in spoken English is "mil"; this can cause confusion since in the United States, "mil" traditionally means a thousandth of an inch. For the purposes of compatibility with Chinese and Korean characters, Unicode has symbols for: millimetre - code U+339C square millimetre - code U+339F cubic millimetre - code U+33A3In Japanese typography, these square symbols were used for laying out unit symbols without distorting the grid layout of text characters.
On a metric ruler, the smallest measurements are millimetres. High-quality engineering rules may be graduated in increments of 0.5 mm. Digital callipers are capable of reading increments as small as 0.01 mm. Microwaves with a frequency of 300 GHz have a wavelength of 1 mm. Using wavelengths between 30 GHz and 300 GHz for data transmission, in contrast to the 300 MHz to 3 GHz used in mobile devices, has the potential to allow data transfer rates of 10 gigabits per second; the smallest distances the human eye can resolve is around 0.02 to 0.04 mm the width of a human hair. A sheet of paper is between 0.07 mm and 0.18 mm thick, with ordinary printer paper or copy paper a tenth of a millimetre thick. Metric system Orders of magnitude Submillimeter
The quarter eagle was a gold coin issued by the United States with a denomination of two hundred and fifty cents, or two dollars and fifty cents. It was given its name as a derivation from the US ten-dollar eagle coin, its purchasing power in 1800 would be equivalent to $71.12 in 2015 dollars. Designed by Robert Scot, the quarter eagle denomination was struck at the main mint at Philadelphia, branch mints in Charlotte, New Orleans, Denver; the first issues weighed 67.5 grains, fineness.9167, until the weight was modified to 64.5 grains and the fineness changed to.8992 by the Act of June 28, 1834. The Act of January 18, 1837 established a fineness of.900. This means that 1837 and quarter eagles contain 0.121 Troy Oz. of gold content. As fewer coins were struck prior to 1834, combined with their higher gold content, all of the early issues range from scarce to rare; the first issues were struck in 1796. Any proof date prior to 1856 is rare, will command a premium in any condition; the quarter eagle denomination was discontinued in 1933 with the removal of the United States from the Gold Standard, although the last date of issue was 1929.
Known as the "Turban Head", this interpretation of Liberty wearing a turban-like cap was designed by Robert Scot and was minted from 1796 to 1807. There were three varieties of this design. First came the Capped Bust facing right variety. There were two variations of this design, no stars on the obverse, stars on the obverse. The'no stars' variety was produced only in 1796, replaced with the stars. In 1808, Liberty was redesigned by John Reich, to be wearing more of a traditional cap rather than a turban; this design was minted for 1808 only, but in 1821 the mint reinstated the quarter eagle and it was produced again until 1827 scaled down to 18.5 millimeters from the original 20. In 1829, the quarter eagle was reduced in size again to 18.2 mm, featured smaller letters and stars. This version of the design was produced until 1834; the "Classic Head" variety was designed by William Kneass, which featured a traditional maiden with a ribbon binding her long, curly hair. This variety omitted. In 1840, a coronet and smaller head were designed to conform with the appearance of the larger gold coins, therefore making the Classic Head design obsolete.
The Classic Head design was produced from 1834 to 1839. Known as the "Coronet Head", the Liberty head was designed to match the styles of the other gold Eagles the government was producing; the Liberty Head design was created by Christian Gobrecht and was produced from 1840 to 1907, the most popular of all of the models. Like its predecessor, this variety omitted E Pluribus Unum from the reverse. One notable date is 1848, when 230 ounces of gold were sent to the Secretary of War Marcy by Colonel R. B. Mason, the military governor of California; the gold was promptly made into quarter eagles. The distinguishing mark CAL. was punched above the heraldic eagle on the reverse side of the coin. Only 1,389 of these coins were minted and are sought after by collectors. There are several specimens with proof-like surfaces and the coins are sought after by collectors fetching prices from $30,000 to $100,000 if in good enough condition; the "Indian Head" design and the similar Half Eagle piece were created by Boston sculptor Bela Lyon Pratt.
The coin was a departure from other examples of American coinage because it had no raised edges, instead featuring a design sunk into the planchet. The public had much distaste for the experimental and unusual design. Many feared that the recessed surfaces would collect germs, others thought it was ugly. Numismatists took little interest in the coin; this resulted in few examples in uncirculated condition and the coin slipped into obscurity for many years. Today, collectors adore the exotic design and the coin is recognized as part of the creative renaissance of American coinage; the Indian Head design was produced from 1908 to 1929. Two of the Early United States commemorative coins are Quarter eagles; the 1915-S was produced for the Panama-Pacific Exposition in San Francisco. The obverse depicts Liberty riding a Hippocampus. With only 6,749 sold it is quite valuable. More common is the 1926 issue struck to commemorate the Sesquicentennial Exposition in Philadelphia. A total of 46,019 pieces were sold.
The obverse shows Liberty standing on a globe and holding a torch and the Declaration of Independence, while the reverse pictures Independence Hall. Since the resumption of commemorative gold coin mintage in 1984 none have been struck in this denomination. US Quarter Eagle by year and type. Histories and more. 1915-S PANAMA-PACIFIC COMMEMORATIVE QUARTER EAGLE 1926 SESQUICENTENNIAL QUARTER EAGLE
The copper-nickel three-cent piece called a three-cent nickel piece or three-cent nickel, was designed by US Mint Chief Engraver James B. Longacre and struck by the United States Bureau of the Mint from 1865 to 1889, it was popular, but its place in commerce was supplanted by the five-cent piece, or nickel. With precious metal federal coinage hoarded during the economic turmoil of the American Civil War, including the silver three-cent piece, the copper-nickel cent commanding a premium, Congress issued paper money in denominations as small as three cents to replace the hoarded coins in commerce; these small slips of paper became ragged and dirty, the public came to hate "shinplasters". After the issuance in 1864 of a lighter bronze cent and a two-cent piece of that metal, both of which circulated there were proposals for a three-cent piece in copper-nickel to replace the three-cent note; the advocates were led by Pennsylvania industrialist Joseph Wharton, who controlled the domestic supply of nickel ore.
On the last legislative day of the congressional session, March 3, 1865, a bill for a three-cent piece in copper-nickel alloy was introduced in Congress, passed both houses without debate, was signed by President Abraham Lincoln. The three-cent nickel piece circulated well, but became less popular when the five-cent nickel was introduced in 1866, a larger, more convenient coin, with a value of five cents better fitting the decimal system. After 1870, most years saw low annual mintages for the three-cent nickel, in 1890 Congress abolished it; the last were struck in 1889. The issue is not collected, prices for rare dates remain low by the standards of American collectible coinage; the great influx of bullion from the California Gold Rush and other finds caused the price of silver relative to gold to increase starting in 1848, silver coins were hoarded or exported for melting. In 1851, a bill for a three-cent piece in 75% silver and 25% copper was introduced in Congress by New York Senator Daniel S. Dickinson, who wanted to lower postage rates from five to three cents.
This percentage of silver was less than the normal 90% so that the coins would circulate at a time of hoarding. The copper large cent did not circulate in the Pacific Coast region or South due to prejudice against coins that did not contain precious metal, some means of allowing the purchase of a postage stamp without the use of copper cents was necessary. Dickinson's bill passed on March 3, 1851, in addition to authorizing the new three-cent silver, lowered rates for most domestic mails. By 1854, the imbalance had abated, Congress increased the silver content of the three-cent piece to the standard 90% for silver coins, though its weight was reduced; the large cent was replaced by a smaller version made of 88% copper and 12% nickel in 1857. In 1861, the Civil War began, when efforts to finance the war via borrowing failed, the Treasury stopped paying out gold in December 1861; the United States shifted to a paper money-based economy with little disruption. By June 1862, the price of silver had risen to the point where coins of that metal vanished from circulation, many exported to Canada, where they were both acceptable in circulation, could be exchanged for gold.
This departure of low-value coins was far more disruptive to commerce than the loss of the high-denomination gold coins, change in transactions was made by a variety of makeshifts. These included currency issues by cities and businesses, encased postage stamps, federally issued fractional currency—paper notes in denominations as small as three cents; the low-value paper currency, whether issued by government or business, were called shinplasters by the public, which disliked them. On the Pacific Coast, where paper money was not favored and gold continued to circulate. Since fractional currency in three-cent denominations did not appear until late 1864, the cent was the only means circulating of making change from the five-cent note, came, in 1862 and 1863, to command a premium when sold in lots, of about 4%; the Philadelphia Mint tried to keep up with demand, limiting public purchases of cents to five dollars, sending shipments to major cities. Despite these attempts, Mint Director James Pollock noted in his annual reports that cents were unobtainable, hoarded despite the fact that their metallic value remained less than one cent each.
Numismatist Neil Carothers theorized that they were put aside by the public as the only circulating federal coinage, made of metal at a time when the public was forced to accept flimsy pieces of paper instead of silver and gold. With cents from the Philadelphia Mint selling at a premium, many private token issues were issued in 1863, passed as cents in commerce. Mint officials took notice that the tokens made of bronze rather than the copper-nickel alloy being used in the cent, were not hoarded and began to consider issuing bronze coins; when Pollock proposed legislation for bronze one-, two-, three-cent pieces, it was opposed by industrialist Joseph Wharton, owner of the major source of nickel in the United States at the time, a mine at Gap, Pennsylvania. Pollock's bill, as introduced, provided for one- and two-cent pieces of bronze, the Wharton interests opposed it. According to Carothers, Congress declined to compromise with the nickel interests... In the House, its opponents managed to delay its passage for a month.
Thaddeus Stevens, one of the most influential men in the House, fought it bitterly, however, that he objected to it because it adversely affected Wharton's interests. The Coinage Act of 1864 passed into law on April 22 of that year. After entering circulation several months the bronze cent an