Accademia dei Lincei
The Accademia dei Lincei is an Italian science academy, located at the Palazzo Corsini on the Via della Lungara in Rome, Italy. Founded in the Papal States in 1603 by Federico Cesi, the academy was named after the lynx, an animal whose sharp vision symbolizes the observational prowess that science requires. Galileo Galilei was the intellectual centre of the academy and adopted "Galileo Galilei Linceo" as his signature. "The Lincei did not long survive the death in 1630 of Cesi, its founder and patron", "disappeared in 1651". During the nineteenth century, it was revived, first in the Vatican and in the nation of Italy, thus the Pontifical Academy of Science, founded in 1847, claims this heritage as the Accademia Pontificia dei Nuovi Lincei, descending from the first two incarnations of the Academy. A lynx-eyed academy of the 1870s became the national academy of Italy, encompassing both literature and science among its concerns; the first Accademia dei Lincei was founded in 1603 by Federico Cesi, an aristocrat from Umbria, passionately interested in natural history – botany.
Cesi's father disapproved of the research career. His mother, Olimpia Orsini, supported him both morally; the Academy struggled due to this disapproval, but after the death of Frederico's father he had enough money to allow the academy to flourish. The academy, hosted in Palazzo Cesi-Armellini near Saint Peter, replaced the first scientific community Giambattista della Porta's Academia Secretorum Naturae in Naples, closed by the Inquisition. Cesi founded the Accademia dei Lincei with three friends: the Dutch physician Johannes van Heeck and two fellow Umbrians, mathematician Francesco Stelluti and polymath Anastasio de Filiis. At the time of the Accademia's founding Cesi was only 18, the others only 8 years older. Cesi and his friends aimed to understand all of the natural sciences; the literary and antiquarian emphasis set the "Lincei" apart from the host of sixteenth and seventeenth century Italian Academies. Cesi envisioned a program of free experiment, respectful of tradition, yet unfettered by blind obedience to authority that of Aristotle and Ptolemy, whose theories the new science called into question.
While a private association, the Academy became a semi-public establishment during the Napoleonic domination of Rome. This shift allowed local scientific elite to carve out a place for themselves in larger scientific networks. However, as a semi-public establishment, the Academy's focus was directed by Napoleonic politics; this focus directed the member's efforts towards stimulating industry, turning public opinion in favor of the French regime and secularizing the country. The name "Lincei" came from Giambattista della Porta's book "Magia Naturalis," which had an illustration of the fabled cat on the cover and the words "...with lynx like eyes, examining those things which manifest themselves, so that having observed them, he may zealously use them". Accademia dei Lincei's symbols were both an eagle; the academy's motto, chosen by Cesi, was: "Take care of small things if you want to obtain the greatest results". According to T. O'Conor Sloane, their other motto was Sagacius ista; when Cesi visited Naples, he met with many scientists in fields of interest to him including the botanist, Fabio Colonna, the natural history writer, Ferrante Imperato, the polymath della Porta.
Della Porta was impressed with Cesi, dedicated three works to the Linceans including a treatise on distillation called De Distillatione, a book on curvilinear geometry called Elementa Curvilinea, The Transformations of the Atmosphere. Della Porta encouraged Cesi to continue with his endeavours. Giambattista della Porta joined Cesi's academy in 1610. While in Naples, Cesi met with Nardo Antonio Recchi to negotiate the acquisition of a collection of material describing Aztec plants and animals written by Francisco Hernández de Toledo; this collection of material would become the Tesoro Messicano. The goal was anything less than the assembly of modern science reflected on the method of observation: the church of knowledge; the Academy was to possess in each quarter of the global communes with adequate endowments to retain membership. These communes were complete with libraries, museums, printing presses, botanical gardens. Members wrote letters around their observations; the Lyncæis denounced marriage as a mollis and effeminata requies.
Membership was banned to monks. Members were ordered to "penetrate into the interior of things in order to know the causes and operations of nature, as it is said the lynx does, which sees not only what is outside, but what is hidden within."Galileo was inducted to the exclusive Academy on April 25, 1611, became its intellectual center. Galileo felt honoured by his association with the Academy for he adopted Galileo Galilei Linceo as his signature; the Academy supported him during his disputes with the Roman Inquisition. Among the Academy's early publications in the fields of astronomy and botany were Galileo's "Letters on Sunspots" and "The Assayer", the Tesoro Messicano describing the flora and drugs of the New World, which took decades of labor, down to 1651. With this publicati
Italy the Italian Republic, is a country in Southern Europe. Located in the middle of the Mediterranean Sea, Italy shares open land borders with France, Austria and the enclaved microstates San Marino and Vatican City. Italy covers an area of 301,340 km2 and has a temperate seasonal and Mediterranean climate. With around 61 million inhabitants, it is the fourth-most populous EU member state and the most populous country in Southern Europe. Due to its central geographic location in Southern Europe and the Mediterranean, Italy has been home to a myriad of peoples and cultures. In addition to the various ancient peoples dispersed throughout modern-day Italy, the most famous of which being the Indo-European Italics who gave the peninsula its name, beginning from the classical era and Carthaginians founded colonies in insular Italy and Genoa, Greeks established settlements in the so-called Magna Graecia, while Etruscans and Celts inhabited central and northern Italy respectively; the Italic tribe known as the Latins formed the Roman Kingdom in the 8th century BC, which became a republic with a government of the Senate and the People.
The Roman Republic conquered and assimilated its neighbours on the peninsula, in some cases through the establishment of federations, the Republic expanded and conquered parts of Europe, North Africa and the Middle East. By the first century BC, the Roman Empire emerged as the dominant power in the Mediterranean Basin and became the leading cultural and religious centre of Western civilisation, inaugurating the Pax Romana, a period of more than 200 years during which Italy's technology, economy and literature flourished. Italy remained the metropole of the Roman Empire; the legacy of the Roman Empire endured its fall and can be observed in the global distribution of culture, governments and the Latin script. During the Early Middle Ages, Italy endured sociopolitical collapse and barbarian invasions, but by the 11th century, numerous rival city-states and maritime republics in the northern and central regions of Italy, rose to great prosperity through shipping and banking, laying the groundwork for modern capitalism.
These independent statelets served as Europe's main trading hubs with Asia and the Near East enjoying a greater degree of democracy than the larger feudal monarchies that were consolidating throughout Europe. The Renaissance began in Italy and spread to the rest of Europe, bringing a renewed interest in humanism, science and art. Italian culture flourished, producing famous scholars and polymaths such as Michelangelo, Leonardo da Vinci, Raphael and Machiavelli. During the Middle Ages, Italian explorers such as Marco Polo, Christopher Columbus, Amerigo Vespucci, John Cabot and Giovanni da Verrazzano discovered new routes to the Far East and the New World, helping to usher in the European Age of Discovery. Italy's commercial and political power waned with the opening of trade routes that bypassed the Mediterranean. Centuries of infighting between the Italian city-states, such as the Italian Wars of the 15th and 16th centuries, left the region fragmented, it was subsequently conquered and further divided by European powers such as France and Austria.
By the mid-19th century, rising Italian nationalism and calls for independence from foreign control led to a period of revolutionary political upheaval. After centuries of foreign domination and political division, Italy was entirely unified in 1871, establishing the Kingdom of Italy as a great power. From the late 19th century to the early 20th century, Italy industrialised, namely in the north, acquired a colonial empire, while the south remained impoverished and excluded from industrialisation, fuelling a large and influential diaspora. Despite being one of the main victors in World War I, Italy entered a period of economic crisis and social turmoil, leading to the rise of a fascist dictatorship in 1922. Participation in World War II on the Axis side ended in military defeat, economic destruction and the Italian Civil War. Following the liberation of Italy and the rise of the resistance, the country abolished the monarchy, reinstated democracy, enjoyed a prolonged economic boom and, despite periods of sociopolitical turmoil became a developed country.
Today, Italy is considered to be one of the world's most culturally and economically advanced countries, with the sixth-largest worldwide national wealth. Its advanced economy ranks eighth-largest in the world and third in the Eurozone by nominal GDP. Italy owns the third-largest central bank gold reserve, it has a high level of human development, it stands among the top countries for life expectancy. The country plays a prominent role in regional and global economic, military and diplomatic affairs. Italy is a founding and leading member of the European Union and a member of numerous international institutions, including the UN, NATO, the OECD, the OSCE, the WTO, the G7, the G20, the Union for the Mediterranean, the Council of Europe, Uniting for Consensus, the Schengen Area and many more; as a reflection
A swept wing is a wing that angles either backward or forward from its root rather than in a straight sideways direction. Wing sweep has the effect of delaying the shock waves and accompanying aerodynamic drag rise caused by fluid compressibility near the speed of sound, improving performance. Swept wings are therefore used on jet aircraft designed to fly at these speeds. Swept wings are sometimes used for other reasons, such as structural convenience or visibility. Wing sweep at high speeds was first investigated in Germany as early as 1935, but it found no application until just before the end of the Second World War. Swept wings became common on advanced first-generation jet fighters like the MiG-15 and F-86 Sabre, which demonstrated a decisive superiority over the slower first generation of straight-wing jet fighters during the Korean War. Since swept wings have become universal on all but the slowest jets; the term "swept wing" is used to mean "swept back", but other swept variants include forward sweep, variable sweep wings and oblique wings in which one side sweeps forward and the other back.
The delta wing incorporates the same advantages as part of its layout. The characteristic "sweep angle" is measured by drawing a line from root to tip, 25% of the way back from the leading edge, comparing that to the perpendicular to the longitudinal axis of the aircraft. Typical sweep angles vary from 0 for a straight-wing aircraft, to 45 degrees or more for fighters and other high-speed designs. Early aircraft adhered to the basic design of square wings at right angles to the body of the machine, but there were experimentalists who explored other geometries to achieve better aerodynamic results; the swept wing geometry appeared before World War I, was conceived as a means of permitting the design of safe and tailless flying wings. It imposed "self-damping" inherent stability upon the flying wing, and, as a result, many flying wing gliders and some powered aircraft appeared in the interwar years. One of the earliest swept wing designs was used by José Weiss to construct a swept-wing tail-less glider in 1908 in England.
He followed this up with a version powered by an Anzani engine driving two propellers. At the same time the Anglo-Irish engineer J. W. Dunne was experimenting along similar lines, obsessed with achieving innate stability in flight, he was able to employ swept wings in his tailless aircraft as a means of creating positive longitudinal static stability. For a low-speed aircraft, swept wings are useful to avoid problems with the center of gravity, to move the wing spar into a more convenient location, or to improve the sideways view from the pilot's position. In 1905 he had built a glider with swept wings and by 1913 he had constructed successful powered variants that were able to cross the English Channel; the Dunne D.5 was exceptionally aerodynamically stable for the time and the D.8 was sold to the Royal Flying Corps and the United States Navy. His work ceased with the onset of war in 1914, but the idea was taken up by Westland Aircraft in England, who designed a series of gliders and aircraft to Dunne's guidelines, notably the Westland-Hill Pterodactyl in 1931.
However, Dunne's theories met with little acceptance from the leading aircraft designers and companies at the time. The Curtiss XP-55 was the first American swept wing airplane, although it was not considered successful; the idea of using swept wings to reduce high-speed drag was developed in Germany in the 1930s. At a Volta Conference meeting in 1935 in Italy, Dr. Adolf Busemann suggested the use of swept wings for supersonic flight, he noted that the airspeed over the wing was dominated by the normal component of the airflow, not the freestream velocity, so by setting the wing at an angle the forward velocity at which the shock waves would form would be higher. Albert Betz suggested the same effect would be useful in the transonic. After the presentation the host of the meeting, Arturo Crocco, jokingly sketched "Busemann's airplane of the future" on the back of a menu while they all dined. Crocco's sketch showed a classic 1950's fighter design, with swept wings and tail surfaces, although he sketched a swept propeller powering it.
At the time, there was no way to power an aircraft to these sorts of speeds, the fastest aircraft of the era were only approaching 400 km/h. The presentation was of academic interest, soon forgotten. Notable attendees including Theodore von Kármán and Eastman Jacobs did not recall the presentation 10 years when it was re-introduced to them. Hubert Ludewieg of the High-Speed Aerodynamics Branch at the AVA Göttingen in 1939 conducted the first wind tunnel tests to investigate Busemann's theory. Two wings, one with no sweep, one with 45 degrees of sweep were tested at Mach numbers of 0.7 and 0.9 in the 11 x 13 cm wind tunnel. The results of these tests confirmed; the results of the tests were communicated to Albert Betz who passed them on to Willy Messerschmitt in December 1939. The tests were expanded in 1940 to include wings with 15, 30 and -45 degrees of sweep and Mach numbers as high as 1.21. With the introduction of jets in the half of World War II applying sweep became relevant; the German jet-powered Messerschmitt Me 262 and rocket-powered Messerschmitt Me 163 suffered from compressibility effects that made them difficult to control at high speeds.
In addition, the speeds put them into the wave drag regime, anything that could reduce this drag would increas
A ramjet, sometimes referred to as a flying stovepipe or an athodyd, is a form of airbreathing jet engine that uses the engine's forward motion to compress incoming air without an axial compressor or a centrifugal compressor. Because ramjets cannot produce thrust at zero airspeed, they cannot move an aircraft from a standstill. A ramjet-powered vehicle, requires an assisted take-off like a rocket assist to accelerate it to a speed where it begins to produce thrust. Ramjets work most efficiently at supersonic speeds around Mach 3; this type of engine can operate up to speeds of Mach 6. Ramjets can be useful in applications requiring a small and simple mechanism for high-speed use, such as missiles. Weapon designers are looking to use ramjet technology in artillery shells to give added range, they have been used though not efficiently, as tip jets on the end of helicopter rotors. Ramjets differ from pulsejets; as speed increases, the efficiency of a ramjet starts to drop as the air temperature in the inlet increases due to compression.
As the inlet temperature gets closer to the exhaust temperature, less energy can be extracted in the form of thrust. To produce a usable amount of thrust at yet higher speeds, the ramjet must be modified so that the incoming air is not compressed nearly as much; this means that the air flowing through the combustion chamber is still moving fast, in fact it will be supersonic—hence the name supersonic-combustion ramjet, or scramjet. L'Autre Monde: ou les États et Empires de la Lune was the first of three satirical novels written by Cyrano de Bergerac, that are considered among the first science fiction stories. Arthur C Clarke credited this book with inventing the ramjet, being the first example of a rocket-powered space flight; the ramjet was conceived in 1913 by French inventor René Lorin, granted a patent for his device. Attempts to build a prototype failed due to inadequate materials. In 1915, Hungarian inventor Albert Fonó devised a solution for increasing the range of artillery, comprising a gun-launched projectile, to be united with a ramjet propulsion unit, thus giving a long range from low muzzle velocities, allowing heavy shells to be fired from lightweight guns.
Fonó submitted his invention to the Austro-Hungarian Army. After World War I, Fonó returned to the subject of jet propulsion, in May 1928 describing an "air-jet engine" which he described as being suitable for high-altitude supersonic aircraft, in a German patent application. In an additional patent application, he adapted the engine for subsonic speed; the patent was granted in 1932 after four years of examination. In the Soviet Union, a theory of supersonic ramjet engines was presented in 1928 by Boris Stechkin. Yuri Pobedonostsev, chief of GIRD's 3rd Brigade, carried out a great deal of research into ramjet engines; the first engine, the GIRD-04, was designed by I. A. Merkulov and tested in April 1933. To simulate supersonic flight, it was fed by air compressed to 20,000 kilopascals, was fueled with hydrogen; the GIRD-08 phosphorus-fueled ramjet was tested by firing it from an artillery cannon. These shells may have been the first jet-powered projectiles to break the speed of sound. In 1939, Merkulov did further ramjet tests using a two-stage rocket, the R-3.
That August, he developed the first ramjet engine for use as an auxiliary motor of an aircraft, the DM-1. The world's first ramjet-powered airplane flight took place in December 1940, using two DM-2 engines on a modified Polikarpov I-15. Merkulov designed a ramjet fighter "Samolet D" in 1941, never completed. Two of his DM-4 engines were installed on the Yak-7 PVRD fighter, during World War II. In 1940, the Kostikov-302 experimental plane was designed, powered by a liquid fuel rocket for take-off and ramjet engines for flight; that project was cancelled in 1944. In 1947, Mstislav Keldysh proposed a long-range antipodal bomber, similar to the Sänger-Bredt bomber, but powered by ramjet instead of rocket. In 1954, NPO Lavochkin and the Keldysh Institute began development of a Mach 3 ramjet-powered cruise missile, Burya; this project competed with the R-7 ICBM being developed by Sergei Korolev, was cancelled in 1957. On March 1, 2018 President Vladimir Putin announced Russia had developed a nuclear powered ramjet cruise missile capable of extended long range flight.
In 1936, Hellmuth Walter constructed a test engine powered by natural gas. Theoretical work was carried out at BMW and Junkers, as well as DFL. In 1941, Eugen Sänger of DFL proposed a ramjet engine with a high combustion chamber temperature, he constructed large ramjet pipes with 500 millimetres and 1,000 millimetres diameter and carried out combustion tests on lorries and on a special test rig on a Dornier Do 17Z at flight speeds of up to 200 metres per second. With petrol becoming scarce in Germany due to wartime conditions, tests were carried out with blocks of pressed coal dust as a fuel, which were not successful due to slow combustion; the US Navy developed a series of air-to-air missiles under the name of "Gorgon" using different propulsion mechanisms, including ramjet propulsion. The ramjet Gorgon IVs, made by Glenn Martin, were tested in 1948 and 1949 at Naval Air Station Point Mugu; the ramjet engine itself was designed at the University of Southe
Werner Karl Heisenberg was a German theoretical physicist and one of the key pioneers of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent series of papers with Max Born and Pascual Jordan, during the same year, this matrix formulation of quantum mechanics was elaborated, he is known for the Heisenberg uncertainty principle, which he published in 1927. Heisenberg was awarded the 1932 Nobel Prize in Physics "for the creation of quantum mechanics", he made important contributions to the theories of the hydrodynamics of turbulent flows, the atomic nucleus, cosmic rays, subatomic particles, he was instrumental in planning the first West German nuclear reactor at Karlsruhe, together with a research reactor in Munich, in 1957. He was a principal scientist in the Nazi German nuclear weapon project during World War II, he travelled to occupied Copenhagen where he discussed the German project with Niels Bohr. Following World War II, he was appointed director of the Kaiser Wilhelm Institute for Physics, which soon thereafter was renamed the Max Planck Institute for Physics.
He was director of the institute until it was moved to Munich in 1958, when it was expanded and renamed the Max Planck Institute for Physics and Astrophysics. Heisenberg was president of the German Research Council, chairman of the Commission for Atomic Physics, chairman of the Nuclear Physics Working Group, president of the Alexander von Humboldt Foundation. Werner Karl Heisenberg was born in Würzburg, Germany, to Kaspar Ernst August Heisenberg, a secondary school teacher of classical languages who became Germany's only ordentlicher Professor of medieval and modern Greek studies in the university system, his wife, Annie Wecklein, he studied physics and mathematics from 1920 to 1923 at the Ludwig Maximilian University of Munich and the Georg-August University of Göttingen. At Munich, he studied under Wilhelm Wien. At Göttingen, he studied physics with James Franck and mathematics with David Hilbert, he received his doctorate at Munich under Sommerfeld. At Göttingen, under Born, he completed his habilitation in 1924 with a Habilitationsschrift on the anomalous Zeeman effect.
Because Sommerfeld had a sincere interest in his students and knew of Heisenberg's interest in Niels Bohr's theories on atomic physics, Sommerfeld took Heisenberg to Göttingen to attend the Bohr Festival of June 1922. At the event, Bohr was a guest lecturer and gave a series of comprehensive lectures on quantum atomic physics. There, Heisenberg met Bohr for the first time, it had a significant and continuing effect on him. Heisenberg's doctoral thesis, the topic of, suggested by Sommerfeld, was on turbulence; the problem of stability was investigated by the use of the Orr–Sommerfeld equation, a fourth order linear differential equation for small disturbances from laminar flow. He returned to this topic after World War II. In his youth he was a member and Scoutleader of the Neupfadfinder, a German Scout association and part of the German Youth Movement. In August 1923 Robert Honsell and Heisenberg organized a trip to Finland with a Scout group of this association from Munich. Heisenberg arrived at Munich in 1919 as a member of the Freikorps to fight the Bavarian Soviet Republic established a year earlier.
Five decades he recalled those days as youthful fun, like "playing cops and robbers and so on. From 1924 to 1927, Heisenberg was a Privatdozent at Göttingen, meaning he was qualified to teach and examine independently, without having a chair. From 17 September 1924 to 1 May 1925, under an International Education Board Rockefeller Foundation fellowship, Heisenberg went to do research with Niels Bohr, director of the Institute of Theoretical Physics at the University of Copenhagen, his seminal paper, "Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen", was published in September 1925. He returned to Göttingen and, with Max Born and Pascual Jordan over a period of about six months, developed the matrix mechanics formulation of quantum mechanics. On 1 May 1926, Heisenberg began his appointment as a university lecturer and assistant to Bohr in Copenhagen, it was in Copenhagen, in 1927, that Heisenberg developed his uncertainty principle, while working on the mathematical foundations of quantum mechanics.
On 23 February, Heisenberg wrote a letter to fellow physicist Wolfgang Pauli, in which he first described his new principle. In his paper on the principle, Heisenberg used the word "Ungenauigkeit", not uncertainty, to describe it. In 1927, Heisenberg was appointed ordentlicher Professor of theoretical physics and head of the department of physics at the University of Leipzig. In his first paper published from Leipzig, Heisenberg used the Pauli exclusion principle to solve the mystery of ferromagnetism. During Heisenberg's tenure at Leipzig, the high quality of the doctoral students and post-graduate and research associates who studied and worked with him is clear from the acclaim many earned. At various times they included Erich Bagge, Felix Bloch, Ugo Fano, Siegfried Flügge, William Vermillion Houston, Friedrich Hund, Robert S. Mulliken, Rudolf Peierls, George Placzek, Isidor Isaac Rabi, Fritz Sauter, John C. Slater, Edward Teller, John Hasbrouck van Vleck, Victor Frederick Weisskopf, Carl Friedrich von Weizsäcker, Gregor Wentzel, Clarence Zener.
In the context of the history of the 20th century, the interwar period was the period between the end of the First World War in November 1918 and the beginning of the Second World War in September 1939. Despite the short period of time, this period represented an era of significant changes worldwide. Petroleum and associated mechanisation expanded leading to the Roaring Twenties, a period of economic prosperity and growth for the middle class in North America and many other parts of the world. Automobiles, electric lighting, radio broadcasts and more became commonplace among populations in the developed world; the indulgences of this era subsequently were followed by the Great Depression, an unprecedented worldwide economic downturn which damaged many of the world's largest economies. Politically, this era coincided with the rise of communism, starting in Russia with the October Revolution and Russian Civil War, at the end of World War I, ended with the rise of fascism in Germany and in Italy.
China was in the midst of long period of instability and civil war between the Kuomintang and the Communist Party of China. The Empires of Britain and others faced challenges as imperialism was viewed negatively in Europe, independence movements in British India, French Indochina and other regions gained momentum; the Ottoman, Austro-Hungarian and German empires were dismantled, while the Ottoman and German colonies were redistributed among the Allies, chiefly the United Kingdom and France. The western parts of the Russian Empire, Finland, Latvia and Poland became independent nations in their own right, while Bessarabia chose to reunify with Romania; the Russian communists managed to regain control of the other East Slavic states, Central Asia, the Caucasus, forming the Soviet Union. Ireland was partitioned between the independent Irish Free State and the British-controlled Northern Ireland. In the Middle East and Iraq gained independence. During the Great Depression, Latin American countries nationalised many foreign companies in a bid to strengthen their own economies.
The territorial ambitions of the Soviets, Japan and Germany led to the expansion of their empires, setting the stage for the subsequent World War. The Interwar Period is accepted to have ended in September 1939, with the invasion of Poland and the beginning of World War II. However, in Asia, it is considered to have ended with the Marco Polo Bridge Incident and the beginning of the Second Sino-Japanese War. Following the Armistice of Compiègne on November 11th, 1918 that ended World War I, the years 1918–24 were marked by turmoil as the Russian Civil War continued to rage on, Eastern Europe struggled to recover from the devastation of the First World War and the destabilising effects of not just the collapse of the Russian Empire, but the destruction of the German Empire, the Austro-Hungarian Empire, the Ottoman Empire, as well. There were numerous new nations in Eastern Europe, some small in size, such as Lithuania or Latvia, some large and vast, such as Poland and Yugoslavia; the United States gained dominance in world finance.
Thus, when Germany could no longer afford war reparations to Britain and other former members of the Entente, the Americans came up with the Dawes Plan and Wall Street invested in Germany, which repaid its reparations to nations that, in turn, used the dollars to pay off their war debts to Washington. By the middle of the decade, prosperity was widespread, with the second half of the decade known as the Roaring Twenties; the important stages of interwar diplomacy and international relations included resolutions of wartime issues, such as reparations owed by Germany and boundaries. Disarmament was a popular public policy. However, the League of Nations played little role in this effort, with the United States and Britain taking the lead. U. S. Secretary of State Charles Evans Hughes sponsored the Washington Naval Conference of 1921 in determining how many capital ships each major country was allowed; the new allocations were followed and there were no naval races in the 1920s. Britain played a leading role in the 1927 Geneva Naval Conference and the 1930 London Conference that led to the London Naval Treaty, which added cruisers and submarines to the list of ship allocations.
However the refusal of Japan, Germany and the USSR to go along with this led to the meaningless Second London Naval Treaty of 1936. Naval disarmament had collapsed and the issue became rearmi
Alessandro Giuseppe Antonio Anastasio Volta was an Italian physicist, a pioneer of electricity and power, credited as the inventor of the electric battery and the discoverer of methane. He invented the Voltaic pile in 1799, reported the results of his experiments in 1800 in a two-part letter to the President of the Royal Society. With this invention Volta proved that electricity could be generated chemically and debunked the prevalent theory that electricity was generated by living beings. Volta's invention sparked a great amount of scientific excitement and led others to conduct similar experiments which led to the development of the field of electrochemistry. Alessandro Volta drew admiration from Napoleon Bonaparte for his invention, was invited to the Institute of France to demonstrate his invention to the members of the Institute. Volta enjoyed a certain amount of closeness with the Emperor throughout his life and he was conferred numerous honours by him. Alessandro Volta held the chair of experimental physics at the University of Pavia for nearly 40 years and was idolised by his students.
Despite his professional success, Volta tended to be a person inclined towards domestic life and this was more apparent in his years. At this time he tended to live secluded from public life and more for the sake of his family until his eventual death in 1827 from a series of illnesses which began in 1823; the SI unit of electric potential is named in his honour as the volt. Volta was born in Como, a town in present-day northern Italy, on 18 February 1745. In 1794, Volta married an aristocratic lady from Como, Teresa Peregrini, with whom he raised three sons: Zanino and Luigi, his father, Filippo Volta, was of noble lineage. His mother, Donna Maddalena, came from the family of the Inzaghis. In 1774, he became a professor of physics at the Royal School in Como. A year he improved and popularised the electrophorus, a device that produced static electricity, his promotion of it was so extensive that he is credited with its invention though a machine operating on the same principle was described in 1762 by the Swedish experimenter Johan Wilcke.
In 1777, he travelled through Switzerland. There he befriended H. B. de Saussure. In the years between 1776 and 1778, Volta studied the chemistry of gases, he researched and discovered methane after reading a paper by Benjamin Franklin of the United States on "flammable air". In November 1776, he found methane at Lake Maggiore, by 1778 he managed to isolate methane, he devised experiments such as the ignition of methane by an electric spark in a closed vessel. Volta studied what we now call electrical capacitance, developing separate means to study both electrical potential and charge, discovering that for a given object, they are proportional; this is called Volta's Law of Capacitance, it was for this work the unit of electrical potential has been named the volt. In 1779 he became a professor of experimental physics at the University of Pavia, a chair that he occupied for 40 years. Luigi Galvani, an Italian physicist, discovered something he named, "animal electricity" when two different metals were connected in series with a frog's leg and to one another.
Volta realised that the frog's leg served as both a conductor of electricity and as a detector of electricity. He replaced the frog's leg with brine-soaked paper, detected the flow of electricity by other means familiar to him from his previous studies. In this way he discovered the electrochemical series, the law that the electromotive force of a galvanic cell, consisting of a pair of metal electrodes separated by electrolyte, is the difference between their two electrode potentials; this may be called Volta's Law of the electrochemical series. In 1800, as the result of a professional disagreement over the galvanic response advocated by Galvani, Volta invented the voltaic pile, an early electric battery, which produced a steady electric current. Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and copper, he experimented with individual cells in series, each cell being a wine goblet filled with brine into which the two dissimilar electrodes were dipped.
The voltaic pile replaced the goblets with cardboard soaked in brine. In announcing his discovery of the voltaic pile, Volta paid tribute to the influences of William Nicholson, Tiberius Cavallo, Abraham Bennet; the battery made by Volta is credited as one of the first electrochemical cells. It consists of two electrodes: one made of zinc, the other of copper; the electrolyte is either sulfuric acid mixed with a form of saltwater brine. The electrolyte exists in the form 2H+ and SO42−; the zinc, higher in the electrochemical series than both copper and hydrogen, reacts with the negatively charged sulfate. The positively charged hydrogen ions capture electrons from the copper, forming bubbles of hydrogen gas, H2; this makes the copper rod the positive electrode. Thus, there are two terminals, an electric current will flow if they are connected; the chemical reactions in this voltaic cell are as follows: Zinc: Zn → Zn2+ + 2e−Sulfuric acid: 2H+ + 2e− → H2The copper does not react, but rather it functions as an electrode for the electric current.
However, this cell has some disadvantages. It is unsafe to handle, since sulfuric acid if diluted, can be hazardous; the power of the cell diminishes over time because the hydrogen gas is not released. Instead, it accumulates on the surface of