8.13.2016

F-15 Twin engine



F-15 
McDonnell Aircraft formalized the concept for the F-15 in 1967 when the company was selected to enter the second phase of the U.S Air Force's FX competition. Competing against Fairchild Hiller and North American Rockwell, McDonnell used lessons learned during the Vietnam War on the changing nature of jet age air-to-air combat, given that the F-4 Phantom II was earning its reputation as a formidable fighter. On Dec. 23, 1969, after more than two years of intensive testing and evaluation, the Air Force awarded McDonnell Douglas the F-15 Advanced Tactical Fighter contract. The McDonnell Douglas team had placed first among the three competitors in all phases of the competition and had the lowest contract price.

F-15
The F-15 is a twin-engine, high-performance, all-weather air superiority fighter known for its incredible acceleration and maneuverability. With a top speed in excess of Mach 2.5 (more than 1,600 mph or 2575 kph), it was the first U.S. fighter with enough thrust to accelerate vertically. The F-15 carries a large complement of missiles — including AIM-9 Sidewinders and AIM-7 Sparrows; the Boeing-built Small Diameter Bomb I, Joint Direct Attack Munition (JDAM) and Laser JDAM weapons; and an internal 20 mm Gatling gun — all vital for modern engagements.

F-15
On June 26, 1972, James S. McDonnell, founder of McDonnell Aircraft, christened the F-15 "Eagle." Test pilot Irv Burrows took the first F-15 Eagle to the air on July 27, 1972, at Edwards Air Force Base in California. Six months later, the Air Force approved the Eagle for full-rate production.
In early 1975, flying out of Grand Forks Air Force Base in North Dakota, an F-15A known as Streak Eagle set many time-to-climb world records. Between Jan. 16 and Feb. 1, 1975, the Streak Eagle broke eight time-to-climb world records. It reached an altitude of 98,425 feet just 3 minutes, 27.8 seconds from brake release at takeoff and coasted to nearly 103,000 feet before descending.
Eagles flown by Israel's air force were the first to face a true adversary in the air. They downed more than 50 Syrian fighters with no losses of their own. In service with the U.S. Air Force, the F-15 Eagle downed MiG fighters during the Balkan conflict and the majority of Iraq's fixed-wing aircraft during Operation Desert Storm.

F-15
To meet the U.S. Air Force requirement for air-to-ground missions, the F-15E Strike Eagle was developed. It made its first flight from St. Louis in December 1986. The Strike Eagle can carry 23,000 pounds of air-to-ground and air-to-air weapons and is equipped with an advanced navigation and an infrared targeting system, protecting the Strike Eagle from enemy defenses. This allows the Strike Eagle to fly at a low altitude while maintaining a high-speed, even during bad weather or at night.

F-15
The F-15 has been produced in single-seat A model and two-seat B versions. The two-seat F-15E Strike Eagle version is a dual-role fighter that can engage both ground and air targets.
F-15C, -D, and -E models participated in Operation Desert Storm in 1991. F-15 downed 32 of 36 U.S. Air Force air-to-air victories and struck Iraqi ground targets. F-15s served in Bosnia in 1994 and downed three Serbian MiG-29 fighters in Operation Allied Force in 1999. They enforced no-fly zones over Iraq in the 1990s. Eagles also hit Afghan targets in Operation Enduring Freedom, and the F-15E version performed air-to-ground missions in Operation Iraqi Freedom.
Boeing has continued to evolve the F-15 with advanced technology, and it is undefeated in air-to-air combat — 101 aerial victories and 0 defeats. Production continues today with advanced models for several international customers.

F-15
In all models, more than 1,500 F-15s have been built. F-15 will be a major player in the U.S. Air Force air superiority and dominance arsenal through the 2040 timeframe using leading-edge technology and capabilities that will keep the Advanced F-15 and its mission systems current.



Source: boeing
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Alfred Bernhard Nobel


Alfred Bernhard Nobel (21 October 1833 – 10 December 1896) was a Swedish chemist, engineer, innovator, and armaments manufacturer.

Alfred Bernhard Nobel

Known for inventing dynamite, Nobel also owned Bofors (Bofors AB is a Swedish arms manufacturing company. The name has been associated with the iron industry and artillery manufacturing for more than 350 years.), which he had redirected from its previous role as primarily an iron and steel producer to a major manufacturer of cannon and other armaments. Nobel held 355 different patents, dynamite being the most famous. After reading a premature obituary which condemned him for profiting from the sales of arms, he bequeathed his fortune to institute the Nobel Prizes. The synthetic element nobelium was named after him. His name also survives in modern-day companies such as Dynamit Nobel and AkzoNobel, which are descendants of mergers with companies Nobel himself established.

A Lance-Corporal from Finnish 43rd light anti-aircraft divison reloading 40mm Bofors AA-gun already in position near the township of Nokia/Finland, 25 April 1944, during Continuation War. Finland bought license for manufacturing 40-Bofors

Life and career
Born in Stockholm, Alfred Nobel was the third son of Immanuel Nobel (1801–1872), an inventor and engineer, and Carolina Andriette (Ahlsell) Nobel (1805–1889). The couple married in 1827 and had eight children. The family was impoverished, and only Alfred and his three brothers survived past childhood. Through his father, Alfred Nobel was a descendant of the Swedish scientist Olaus Rudbeck (1630–1702), and in his turn the boy was interested in engineering, particularly explosives, learning the basic principles from his father at a young age. Alfred Nobel's interest in technology was inherited from his father, an alumnus of Royal Institute of Technology in Stockholm.
Following various business failures, Nobel's father moved to Saint Petersburg in 1837 and grew successful there as a manufacturer of machine tools and explosives. He invented modern plywood and started work on the "torpedo". In 1842, the family joined him in the city. Now prosperous, his parents were able to send Nobel to private tutors and the boy excelled in his studies, particularly in chemistry and languages, achieving fluency in English, French, German and Russian. For 18 months, from 1841 to 1842, Nobel went to the only school he ever attended as a child, the Jacobs Apologistic School in Stockholm.
As a young man, Nobel studied with chemist Nikolai Zinin; then, in 1850, went to Paris to further the work. There he met Ascanio Sobrero, who had invented nitroglycerin three years before. Sobrero strongly opposed the use of nitroglycerin, as it was unpredictable, exploding when subjected to heat or pressure. But Nobel became interested in finding a way to control and use nitroglycerin as a commercially usable explosive, as it had much more power than gunpowder. At age 18, he went to the United States for four years to study chemistry, collaborating for a short period under inventor John Ericsson, who designed the American Civil War ironclad USS Monitor. Nobel filed his first patent, an English patent for a gas meter, in 1857, while his first Swedish patent, which he received in 1863, was on 'ways to prepare gunpowder'.
The family factory produced armaments for the Crimean War (1853–1856); but, had difficulty switching back to regular domestic production when the fighting ended and they filed for bankruptcy. In 1859, Nobel's father left his factory in the care of the second son, Ludvig Nobel (1831–1888), who greatly improved the business. Nobel and his parents returned to Sweden from Russia and Nobel devoted himself to the study of explosives, and especially to the safe manufacture and use of nitroglycerine (discovered in 1847 by Ascanio Sobrero, one of his fellow students under Théophile-Jules Pelouze at the University of Paris). Nobel invented a detonator in 1863; and, in 1865, he designed the blasting cap.
On 3 September 1864, a shed, used for the preparation of nitroglycerin, exploded at the factory in Heleneborg, Stockholm, killing five people, including Nobel's younger brother Emil. Dogged by more minor accidents but unfazed, Nobel went on to build further factories, focusing on improving the stability of the explosives he was developing. Nobel invented dynamite in 1867, a substance easier and safer to handle than the more unstable nitroglycerin. Dynamite was patented in the US and the UK and was used extensively in mining and the building of transport networks internationally. In 1875 Nobel invented gelignite, more stable and powerful than dynamite, and in 1887 patented ballistite, a predecessor of cordite.
Nobel was elected a member of the Royal Swedish Academy of Sciences in 1884, the same institution that would later select laureates for two of the Nobel prizes, and he received an honorary doctorate from Uppsala University in 1893.

Alfred Nobel's death mask, at Bjorkborn, Nobel's residence in Karlskoga, Sweden.

Nobel's brothers Ludvig and Robert exploited oilfields along the Caspian Sea and became hugely rich in their own right. Nobel invested in these and amassed great wealth through the development of these new oil regions. During his life Nobel issued 355 patents internationally and by his death his business had established more than 90 armaments factories, despite his belief in pacifism.
In 1888, the death of his brother Ludvig caused several newspapers to publish obituaries of Alfred in error. A French obituary stated "Le marchand de la mort est mort" ("The merchant of death is dead").

Death
Accused of “high treason against France” for selling Ballistite to Italy, Nobel moved from Paris to Sanremo, Italy in 1891. On December 10, 1896, Alfred Nobel succumbed to a lingering heart ailment, suffered a stroke, and died. Unbeknownst to his family, friends or colleagues, he had left most of his wealth in trust, in order to fund the awards that would become known as the Nobel Prizes. He is buried in Norra begravningsplatsen in Stockholm.

Inventions
Nobel found that when nitroglycerin was incorporated in an absorbent inert substance like kieselguhr (diatomaceous earth) it became safer and more convenient to handle, and this mixture he patented in 1867 as 'dynamite'. Nobel demonstrated his explosive for the first time that year, at a quarry in Redhill, Surrey, England. In order to help reestablish his name and improve the image of his business from the earlier controversies associated with the dangerous explosives, Nobel had also considered naming the highly powerful substance "Nobel's Safety Powder", but settled with Dynamite instead, referring to the Greek word for "power" .

Alfred Nobel with women mixing dynamite

Nobel later on combined nitroglycerin with various nitrocellulose compounds, similar to collodion, but settled on a more efficient recipe combining another nitrate explosive, and obtained a transparent, jelly-like substance, which was a more powerful explosive than dynamite. 'Gelignite', or blasting gelatin, as it was named, was patented in 1876; and was followed by a host of similar combinations, modified by the addition of potassium nitrate and various other substances.

Nobel fabrik dynamite wooden box

Gelignite was more stable, transportable and conveniently formed to fit into bored holes, like those used in drilling and mining, than the previously used compounds and was adopted as the standard technology for mining in the Age of Engineering bringing Nobel a great amount of financial success, though at a significant cost to his health. An offshoot of this research resulted in Nobel's invention of ballistite, the precursor of many modern smokeless powder explosives and still used as a rocket propellant.


Nobel Prizes
In 1888 Alfred's brother Ludvig died while visiting Cannes and a French newspaper erroneously published Alfred's obituary. It condemned him for his invention of dynamite and is said to have brought about his decision to leave a better legacy after his death. The obituary stated, Le marchand de la mort est mort ("The merchant of death is dead") and went on to say, "Dr. Alfred Nobel, who became rich by finding ways to kill more people faster than ever before, died yesterday." Alfred (who never had a wife or children) was disappointed with what he read and concerned with how he would be remembered.


Nobel Prize

On 27 November 1895, at the Swedish-Norwegian Club in Paris, Nobel signed his last will and testament and set aside the bulk of his estate to establish the Nobel Prizes, to be awarded annually without distinction of nationality. After taxes and bequests to individuals, Nobel's will allocated 94% of his total assets, 31,225,000 Swedish kronor, to establish the five Nobel Prizes. This converted to £1,687,837 (GBP) at the time. In 2012, the capital was worth around SEK 3.1 billion (USD 472 million, EUR 337 million), which is almost twice the amount of the initial capital, taking inflation into account.

Nobel Prize Award Ceremony, Stockholm 2007

The first three of these prizes are awarded for eminence in physical science, in chemistry and in medical science or physiology; the fourth is for literary work "in an ideal direction" and the fifth prize is to be given to the person or society that renders the greatest service to the cause of international fraternity, in the suppression or reduction of standing armies, or in the establishment or furtherance of peace congresses.
The formulation for the literary prize being given for a work "in an ideal direction" (i idealisk riktning in Swedish), is cryptic and has caused much confusion. For many years, the Swedish Academy interpreted "ideal" as "idealistic" (idealistisk) and used it as a reason not to give the prize to important but less romantic authors, such as Henrik Ibsen and Leo Tolstoy. This interpretation has since been revised, and the prize has been awarded to, for example, Dario Fo and José Saramago, who do not belong to the camp of literary idealism.
There was room for interpretation by the bodies he had named for deciding on the physical sciences and chemistry prizes, given that he had not consulted them before making the will. In his one-page testament, he stipulated that the money go to discoveries or inventions in the physical sciences and to discoveries or improvements in chemistry. He had opened the door to technological awards, but had not left instructions on how to deal with the distinction between science and technology. Since the deciding bodies he had chosen were more concerned with the former, the prizes went to scientists more often than engineers, technicians or other inventors.
In 2001, Alfred Nobel's great-great-nephew, Peter Nobel (b. 1931), asked the Bank of Sweden to differentiate its award to economists given "in Alfred Nobel's memory" from the five other awards. This request added to the controversy over whether the Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel is actually a legitimate "Nobel Prize".


Source: Wikipedia
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8.09.2016

SIR ISAAC NEWTON

Portrait of Sir Issac Newton by Jean-Leon Huens.
Newton, Sir Isaac (1642-1727), mathematician and physicist, one of the foremost scientific intellects of all time. Born at Woolsthorpe, near Grantham in Lincolnshire, where he attended school, he entered Cambridge University in 1661; he was elected a Fellow of Trinity College in 1667, and Lucasian Professor of Mathematics in 1669. He remained at the university, lecturing in most years, until 1696. Of these Cambridge years, in which Newton was at the height of his creative power, he singled out 1665-1666 (spent largely in Lincolnshire because of plague in Cambridge) as "the prime of my age for invention". During two to three years of intense mental effort he prepared Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) commonly known as the Principia, although this was not published until 1687.

Portrait of Newton in 1689 by Godfrey Kneller
As a firm opponent of the attempt by King James II to make the universities into Catholic institutions, Newton was elected Member of Parliament for the University of Cambridge to the Convention Parliament of 1689, and sat again in 1701-1702. Meanwhile, in 1696 he had moved to London as Warden of the Royal Mint. He became Master of the Mint in 1699, an office he retained to his death. He was elected a Fellow of the Royal Society of London in 1671, and in 1703 he became President, being annually re-elected for the rest of his life. His major work, Opticks, appeared the next year; he was knighted in Cambridge in 1705.
Newton in a 1702 portrait by Godfrey Kneller
As Newtonian science became increasingly accepted on the Continent, and especially after a general peace was restored in 1714, following the War of the Spanish Succession, Newton became the most highly esteemed natural philosopher in Europe. His last decades were passed in revising his major works, polishing his studies of ancient history, and defending himself against critics, as well as carrying out his official duties. Newton was modest, diffident, and a man of simple tastes. He was angered by criticism or opposition, and harboured resentment; he was harsh towards enemies but generous to friends. In government, and at the Royal Society, he proved an able administrator. He never married and lived modestly, but was buried with great pomp in Westminster Abbey.
isaac newton reflecting telescope
Newton has been regarded for almost 300 years as the founding examplar of modern physical science, his achievements in experimental investigation being as innovative as those in mathematical research. With equal, if not greater, energy and originality he also plunged into chemistry, the early history of Western civilization, and theology; among his special studies was an investigation of the form and dimensions, as described in the Bible, of Solomon's Temple in Jerusalem.

OPTICS
In 1664, while still a student, Newton read recent work on optics and light by the English physicists Robert Boyle and Robert Hooke; he also studied both the mathematics and the physics of the French philosopher and scientist René Descartes. He investigated the refraction of light by a glass prism; developing over a few years a series of increasingly elaborate, refined, and exact experiments, Newton discovered measurable, mathematical patterns in the phenomenon of colour. He found white light to be a mixture of infinitely varied coloured rays (manifest in the rainbow and the spectrum), each ray definable by the angle through which it is refracted on entering or leaving a given transparent medium. 
Sir Isaac Newton discovered the phenomenon of light dispersion in 1666, the splitting of white light into colours by a prism.
He correlated this notion with his study of the interference colours of thin films (for example, of oil on water, or soap bubbles), using a simple technique of extreme acuity to measure the thickness of such films. He held that light consisted of streams of minute particles. From his experiments he could infer the magnitudes of the transparent "corpuscles" forming the surfaces of bodies, which, according to their dimensions, so interacted with white light as to reflect, selectively, the different observed colours of those surfaces.
dispersion of colours by the prism
The roots of these unconventional ideas were with Newton by about 1668; when first expressed (tersely and partially) in public in 1672 and 1675, they provoked hostile criticism, mainly because colours were thought to be modified forms of homogeneous white light. Doubts, and Newton's rejoinders, were printed in the learned journals. Notably, the scepticism of Christiaan Huygens and the failure of the French physicist Edmé Mariotte to duplicate Newton's refraction experiments in 1681 set scientists on the Continent against him for a generation. The publication of Opticks, largely written by 1692, was delayed by Newton until the critics were dead. The book was still imperfect: the colours of diffraction defeated Newton. Nevertheless, Opticks established itself, from about 1715, as a model of the interweaving of theory with quantitative experimentation.

MATHEMATICS
In mathematics too, early brilliance appeared in Newton's student notes. He may have learnt geometry at school, though he always spoke of himself as self-taught; certainly he advanced through studying the writings of his compatriots William Oughtred and John Wallis, and of Descartes and the Dutch school. Newton made contributions to all branches of mathematics then studied, but is especially famous for his solutions to the contemporary problems in analytical geometry of drawing tangents to curves (differentiation) and defining areas bounded by curves (integration). Not only did Newton discover that these problems were inverse to each other, but he discovered general methods of resolving problems of curvature, embraced in his "method of fluxions" and "inverse method of fluxions", respectively equivalent to Leibniz's later differential and integral calculus. Newton used the term "fluxion" (from Latin meaning "flow") because he imagined a quantity "flowing" from one magnitude to another. Fluxions were expressed algebraically, as Leibniz's differentials were, but Newton made extensive use also (especially in the Principia) of analogous geometrical arguments. Late in life, Newton expressed regret for the algebraic style of recent mathematical progress, preferring the geometrical method of the Classical Greeks, which he regarded as clearer and more rigorous.
Newton's work on pure mathematics was virtually hidden from all but his correspondents until 1704, when he published, with Opticks, a tract on the quadrature of curves (integration) and another on the classification of the cubic curves. His Cambridge lectures, delivered from about 1673 to 1683, were published in 1707.

In the 1690s Newton's friends proclaimed the priority of Newton's methods of fluxions. Supporters of Leibniz asserted that he had communicated the differential method to Newton, although Leibniz had claimed no such thing. Newtonians then asserted, rightly, that Leibniz had seen papers of Newton's during a London visit in 1676; in reality, Leibniz had taken no notice of material on fluxions. A violent dispute sprang up, part public, part private, extended by Leibniz to attacks on Newton's theory of gravitation and his ideas about God and creation; it was not ended even by Leibniz's death in 1716. The dispute delayed the reception of Newtonian science on the Continent, and dissuaded British mathematicians from sharing the researches of Continental colleagues for a century.
Newton's own copy of his Principia, with hand written corrections for the second edition
MECHANICS AND GRAVITATION
According to the well-known story, it was on seeing an apple fall in his orchard at some time during 1665 or 1666 that Newton conceived that the same force governed the motion of the Moon and the apple. He calculated the force needed to hold the Moon in its orbit, as compared with the force pulling an object to the ground. He also calculated the centripetal force needed to hold a stone in a sling, and the relation between the length of a pendulum and the time of its swing. These early explorations were not soon exploited by Newton, though he studied astronomy and the problems of planetary motion.
Newton, apple and gravity
Correspondence with Hooke (1679-1680) redirected Newton to the problem of the path of a body subjected to a centrally directed force that varies as the inverse square of the distance; he determined it to be an ellipse, so informing Edmond Halley in August 1684. Halley's interest led Newton to demonstrate the relationship afresh, to compose a brief tract on mechanics, and finally to write the Principia.
Book I of the Principia states the foundations of the science of mechanics, developing upon them the mathematics of orbital motion round centres of force. Newton identified gravitation as the fundamental force controlling the motions of the celestial bodies. He never found its cause. To contemporaries who found the idea of attractions across empty space unintelligible, he conceded that they might prove to be caused by the impacts of unseen particles.
Book II inaugurates the theory of fluids: Newton solves problems of fluids in movement and of motion through fluids. From the density of air he calculated the speed of sound waves.
Book III shows the law of gravitation at work in the universe: Newton demonstrates it from the revolutions of the six known planets, including the Earth, and their satellites. However, he could never quite perfect the difficult theory of the Moon's motion. Comets were shown to obey the same law; in later editions, Newton added conjectures on the possibility of their return. He calculated the relative masses of heavenly bodies from their gravitational forces, and the oblateness of Earth and Jupiter, already observed. He explained tidal ebb and flow and the precession of the equinoxes from the forces exerted by the Sun and Moon. All this was done by exact computation.
Newton's work in mechanics was accepted at once in Britain, and universally after half a century. Since then it has been ranked among humanity's greatest achievements in abstract thought. It was extended and perfected by others, notably Pierre Simon de Laplace, without changing its basis and it survived into the late 19th century before it began to show signs of failing. See Quantum Theory; Relativity.

ALCHEMY AND CHEMISTRY
Newton left a mass of manuscripts on the subjects of alchemy and chemistry, then closely related topics. Most of these were extracts from books, bibliographies, dictionaries, and so on, but a few are original. He began intensive experimentation in 1669, continuing till he left Cambridge, seeking to unravel the meaning that he hoped was hidden in alchemical obscurity and mysticism. He sought understanding of the nature and structure of all matter, formed from the "solid, massy, hard, impenetrable, movable particles" that he believed God had created. Most importantly in the "Queries" appended to "Opticks" and in the essay "On the Nature of Acids" (1710), Newton published an incomplete theory of chemical force, concealing his exploration of the alchemists, which became known a century after his death.




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8.08.2016

JUPITER THE BIGGEST PLANET IN THE SOLAR SYSTEM

Jupiter

Jupiter is the fifth planet from the Sun and the largest in the Solar System. It is a giant planet with a mass one-thousandth that of the Sun, but two and a half times that of all the other planets in the Solar System combined. Jupiter is a gas giant, along with Saturn, with the other two giant planets, Uranus and Neptune, being ice giants. Jupiter was known to astronomers of ancient times.


Our solar system
The Romans named it after their god Jupiter. When viewed from Earth, Jupiter can reach an apparent magnitude of −2.94, bright enough for its reflected light to cast shadows, and making it on average the third-brightest object in the night sky after the Moon and Venus.


(Jupiter the roman god = Zeus the greek) Jupiter  is the king of the gods and the god of sky and thunder  in Ancient Roman religion and mythology


Jupiter is primarily composed of hydrogen with a quarter of its mass being helium, though helium comprises only about a tenth of the number of molecules. It may also have a rocky core of heavier elements, but like the other giant planets, Jupiter lacks a well-defined solid surface. Because of its rapid rotation, the planet's shape is that of an oblate spheroid (it has a slight but noticeable bulge around the equator). The outer atmosphere is visibly segregated into several bands at different latitudes, resulting in turbulence and storms along their interacting boundaries. A prominent result is the Great Red Spot, a giant storm that is known to have existed since at least the 17th century when it was first seen by telescope. Surrounding Jupiter is a faint planetary ring system and a powerful magnetosphere. Jupiter has at least 67 moons, including the four large Galilean moons discovered by Galileo Galilei in 1610. Ganymede, the largest of these, has a diameter greater than that of the planet Mercury.


This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of liquid metallic hydrogen.

Jupiter has been explored on several occasions by robotic spacecraft, most notably during the early Pioneer and Voyager flyby missions and later by the Galileo orbiter. In late February 2007, Jupiter was visited by the New Horizons probe, which used Jupiter's gravity to increase its speed and bend its trajectory en route to Pluto. The latest probe to visit the planet is Juno, which entered into orbit around Jupiter on July 4, 2016. Future targets for exploration in the Jupiter system include the probable ice-covered liquid ocean of its moon Europa.

Formation and migration
Earth and its neighbor planets may have formed from fragments of planets after collisions with Jupiter destroyed those super-Earths near the Sun. As Jupiter came toward the inner Solar System, in what theorists call the Grand Tack Hypothesis, gravitational tugs and pulls occurred causing a series of collisions between the super-Earths as their orbits began to overlap.
Astronomers have discovered nearly 500 planetary systems with multiple planets. Regularly these systems include a few planets with masses several times greater than Earth's (super-Earths), orbiting closer to their star than Mercury is to the Sun, and sometimes also Jupiter-mass gas giants close to their star.
Jupiter moving out of the inner Solar System would have allowed the formation of inner planets, including Earth.

Physical characteristics
Jupiter is composed primarily of gaseous and liquid matter. It is the largest of the four giant planets in the Solar System and hence its largest planet. It has a diameter of 142,984 km (88,846 mi) at its equator. The average density of Jupiter, 1.326 g/cm3, is the second highest of the giant planets, but lower than those of the four terrestrial planets.

Composition
Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules. A helium atom has about four times as much mass as a hydrogen atom, so the composition changes when described as the proportion of mass contributed by different atoms. Thus, Jupiter's atmosphere is approximately 75% hydrogen and 24% helium by mass, with the remaining one percent of the mass consisting of other elements. The interior contains denser materials, such that the distribution is roughly 71% hydrogen, 24% helium, and 5% other elements by mass. The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. The outermost layer of the atmosphere contains crystals of frozen ammonia. Through infrared and ultraviolet measurements, trace amounts of benzene and other hydrocarbons have also been found.

The atmospheric proportions of hydrogen and helium are close to the theoretical composition of the primordial solar nebula. Neon in the upper atmosphere only consists of 20 parts per million by mass, which is about a tenth as abundant as in the Sun. Helium is also depleted to about 80% of the Sun's helium composition. This depletion is a result of precipitation of these elements into the interior of the planet.

Based on spectroscopy, Saturn is thought to be similar in composition to Jupiter, but the other giant planets Uranus and Neptune have relatively less hydrogen and helium.

Mass and size
Jupiter's mass is 2.5 times that of all the other planets in the Solar System combined—this is so massive that its barycenter with the Sun lies above the Sun's surface at 1.068 solar radii from the Sun's center. Jupiter is much larger than Earth and considerably less dense: its volume is that of about 1,321 Earths, but it is only 318 times as massive. Jupiter's radius is about 1/10 the radius of the Sun, and its mass is 0.001 times the mass of the Sun, so the densities of the two bodies are similar. A "Jupiter mass" (MJ or MJup) is often used as a unit to describe masses of other objects, particularly extrasolar planets and brown dwarfs. So, for example, the extrasolar planet HD 209458 b has a mass of 0.69 MJ, while Kappa Andromedae b has a mass of 12.8 MJ.

mass comparison with earth

Theoretical models indicate that if Jupiter had much more mass than it does at present, it would shrink.[30] For small changes in mass, the radius would not change appreciably, and above about 500 M⊕(⊕:earth mass) (1.6 Jupiter masses) the interior would become so much more compressed under the increased pressure that its volume would decrease despite the increasing amount of matter. As a result, Jupiter is thought to have about as large a diameter as a planet of its composition and evolutionary history can achieve. The process of further shrinkage with increasing mass would continue until appreciable stellar ignition is achieved as in high-mass brown dwarfs having around 50 Jupiter masses.

Although Jupiter would need to be about 75 times as massive to fuse hydrogen and become a star, the smallest red dwarf is only about 30 percent larger in radius than Jupiter. Despite this, Jupiter still radiates more heat than it receives from the Sun; the amount of heat produced inside it is similar to the total solar radiation it receives. This additional heat is generated by the Kelvin–Helmholtz mechanism through contraction. This process causes Jupiter to shrink by about 2 cm each year. When it was first formed, Jupiter was much hotter and was about twice its current diameter.

Internal structure
Jupiter is thought to consist of a dense core with a mixture of elements, a surrounding layer of liquid metallic hydrogen with some helium, and an outer layer predominantly of molecular hydrogen. Beyond this basic outline, there is still considerable uncertainty. The core is often described as rocky, but its detailed composition is unknown, as are the properties of materials at the temperatures and pressures of those depths (see below). In 1997, the existence of the core was suggested by gravitational measurements, indicating a mass of from 12 to 45 times that of Earth, or roughly 4%–14% of the total mass of Jupiter. The presence of a core during at least part of Jupiter's history is suggested by models of planetary formation that require the formation of a rocky or icy core massive enough to collect its bulk of hydrogen and helium from the protosolar nebula. Assuming it did exist, it may have shrunk as convection currents of hot liquid metallic hydrogen mixed with the molten core and carried its contents to higher levels in the planetary interior. A core may now be entirely absent, as gravitational measurements are not yet precise enough to rule that possibility out entirely.

The uncertainty of the models is tied to the error margin in hitherto measured parameters: one of the rotational coefficients (J6) used to describe the planet's gravitational moment, Jupiter's equatorial radius, and its temperature at 1 bar pressure. The Juno mission, which arrived in July 2016, is expected to further constrain the values of these parameters for better models of the core.

The core region is surrounded by dense metallic hydrogen, which extends outward to about 78% of the radius of the planet. Rain-like droplets of helium and neon precipitate downward through this layer, depleting the abundance of these elements in the upper atmosphere.

Above the layer of metallic hydrogen lies a transparent interior atmosphere of hydrogen. At this depth, the pressure and temperature are above hydrogen's critical pressure of 1.2858 MPa and critical temperature of only 32.938 K. In this state, there are no distinct liquid and gas phases—hydrogen is said to be in a supercritical fluid state. It is convenient to treat hydrogen as gas in the upper layer extending downward from the cloud layer to a depth of about 1,000 km, and as liquid in deeper layers. Physically, there is no clear boundary—the gas smoothly becomes hotter and denser as one descends.

The temperature and pressure inside Jupiter increase steadily toward the core, due to the Kelvin–Helmholtz mechanism. At the "surface" pressure level of 10 bars, the temperature is around 340 K (67 °C; 152 °F). At the phase transition region where hydrogen—heated beyond its critical point—becomes metallic, it is calculated the temperature is 10,000 K (9,700 °C; 17,500 °F) and the pressure is 200 GPa. The temperature at the core boundary is estimated to be 36,000 K (35,700 °C; 64,300 °F) and the interior pressure is roughly 3,000–4,500 GPa.

Atmosphere
Jupiter has the largest planetary atmosphere in the Solar System, spanning over 5,000 km (3,000 mi) in altitude. Because Jupiter has no surface, the base of its atmosphere is usually considered to be the point at which atmospheric pressure is equal to 100 kPa (1.0 bar).
Jupiter is perpetually covered with clouds composed of ammonia crystals and possibly ammonium hydrosulfide. The clouds are located in the tropopause and are arranged into bands of different latitudes, known as tropical regions. These are sub-divided into lighter-hued zones and darker belts. The interactions of these conflicting circulation patterns cause storms and turbulence. Wind speeds of 100 m/s (360 km/h) are common in zonal jets. The zones have been observed to vary in width, color and intensity from year to year, but they have remained sufficiently stable for scientists to give them identifying designations.


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NIKOLA TESLA : THE BIOGRAPHY



Nikola Tesla contributed to the development of the alternating-current electrical system that's widely used today and discovered the rotating magnetic field (the basis of most AC machinery).

Nikola Tesla aged 34, (in 1890)
Synopsis

Inventor Nikola Tesla was born in July of 1856, in what is now Croatia. He came to the United States in 1884 and briefly worked with Thomas Edison before the two parted ways. He sold several patent rights, including those to his alternating-current machinery, to George Westinghouse. His 1891 invention, the "Tesla coil," is still used in radio technology today. Tesla died in New York City on January 7, 1943.


Early Life

Nikola Tesla was born on July 10, 1856, in what is now Smiljan, Croatia. Tesla's interest in electrical invention was spurred by his mother, Djuka Mandic, who invented small household appliances in her spare time while her son was growing up. Tesla's father, Milutin Tesla, was a priest and a writer, and he pushed for his son to join the priesthood. But Nikola's interests lay squarely in the sciences. After studying at the Realschule, Karlstadt (later renamed the Johann-Rudolph-Glauber Realschule Karlstadt); the Polytechnic Institute in Graz, Austria; and the University of Prague during the 1870s, Tesla moved to Budapest, where for a time he worked at the Central Telephone Exchange. It was while in Budapest that the idea for the induction motor first came to Tesla, but after several years of trying to gain interest in his invention, at age 28 Tesla decided to leave Europe for America.


Famed Inventor

In 1884 Tesla arrived the United States with little more than the clothes on his back and a letter of introduction to famed inventor and business mogul Thomas Edison, whose DC-based electrical works were fast becoming the standard in the country. Edison hired Tesla, and the two men were soon working tirelessly alongside each other, making improvements to Edison's inventions. However, several months later, the two parted ways due to a conflicting business-scientific relationship, attributed by historians to their incredibly different personalities: While Edison was a power figure who focused on marketing and financial success, Tesla was commercially out-of-tune and somewhat vulnerable.

After parting ways with Edison, in 1885 Tesla received funding for the Tesla Electric Light Company and was tasked by his investors to develop improved arc lighting. After successfully doing so, however, Tesla was forced out of the venture and for a time had to work as a manual laborer in order to survive. His luck changed in 1887, when he was able to find interest in his AC electrical system and funding for his new Tesla Electric Company. Setting straight to work, by the end of the year, Tesla had successfully filed several patents for AC-based inventions.   

Nikola Tesla alternating current

 Tesla's AC system eventually caught the attention of American engineer and business man George Westinghouse, who was seeking a solution to supplying the nation with long-distance power. Convinced that Tesla's inventions would help him achieve this, in 1888 he purchased his patents for $60,000 in cash and stock in the Westinghouse Corporation. As interest in an alternating-current system grew, Tesla and Westinghouse were put in direct competition with Thomas Edison, who was intent on selling his direct-current system to the nation. A negative-press campaign was soon waged by Edison, in an attempt to undermine interest in AC power. Tesla, for his part, continued in his work and would patent several more inventions during this period, including the "Tesla coil," which laid the foundation for wireless technologies and is still used in radio technology today.

A multiple exposure picture (one of 68 images created by Century Magazine photographer Dickenson Alley) of Tesla sitting in his Colorado Springs laboratory with his "magnifying transmitter" generating millions of volts. 

Unfortunately for Thomas Edison, the Westinghouse Corporation was chosen to supply the lighting at the 1893 World's Columbian Exposition in Chicago, and Tesla conducted demonstrations of his AC system there. Two years later, in 1895, Tesla designed what was among the first AC hydroelectric power plants in the United States, at Niagara Falls. The following year, it was used to power the city of Buffalo, New York, a feat that was highly publicized throughout the world. With its repeat successes and favorable press, the alternating-current system would quickly become the preeminent power system of the 20th century, and it has remained the worldwide standard ever since.

Spiral Coil of High-Frequency Transformer in New York, 1896

In addition to his AC system and coil, throughout his career, Tesla discovered, designed and developed ideas for a number of other important inventions—most of which were officially patented by other inventors—including dynamos (electrical generators similar to batteries) and the induction motor. He was also a pioneer in the discovery of radar technology, X-ray technology, remote control and the rotating magnetic field—the basis of most AC machinery.  

US Patent 406,968. Dynamo Electric Machine Nikola Tesla - July 16, 1889.


Portable X-ray Machine


The Fall from Grace

Having become obsessed with the wireless transmission of energy, around 1900 Nikola set to work on his boldest project yet: to build a global, wireless communication system—to be transmitted through a large electrical tower—for sharing information and providing free electricity throughout the world. With funding from a group of investors that included financial giant J. P. Morgan, in 1901 Tesla began work on the project in earnest, designing and building a lab with a power plant and a massive transmission tower on a site on Long Island, New York, that became known as Wardenclyffe. 

Nikola Tesla's Wardenclyffe Tower

However, when doubts arose among his investors about the plausibility of Tesla's system and his rival, Guglielmo Marconi—with the financial support of Andrew Carnegie and Thomas Edison—continued to make great advances with his own radio technologies, Tesla had no choice but to abandon the project. The Wardenclyffe staff was laid off in 1906 and by 1915 the site had fallen into foreclosure. Two years later Tesla declared bankruptcy and the tower was dismantled and sold for scrap to help pay the debts he had accrued.



Death and Legacy

After suffering a nervous breakdown, Tesla eventually returned to work, primarily as a consultant. But as time went on, his ideas became progressively more outlandish and impractical. He also grew increasingly eccentric, devoting much of his time to the care of wild pigeons in New York City's parks. He even drew the attention of the FBI with his talk of building a powerful "death beam," which had received some interest from the Soviet Union during World World II. 
Nikola Tesla, who died on January 7, 1943
Poor and reclusive, Nikola Tesla died on January 7, 1943, at the age of 86, in New York City, where he had lived for nearly 60 years. But the legacy of the work he left behind him lives on to this day.

Source: biography


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8.07.2016

THE HUBBLE SPACE TELESCOPE H.S.T

The Hubble Space Telescope (HST) is a space telescope that was launched into low Earth orbit in 1990, and remains in operation. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well known as both a vital research tool and a public relations boon for astronomy. The HST is named after the astronomer Edwin Hubble, and is one of NASA's Great Observatories, along with the Compton Gamma Ray Observatory, the Chandra X-ray Observatory, and the Spitzer Space Telescope.

Hubble Space Telescope over Earth during the STS-109 mission
With a 2.4-meter (7.9 ft) mirror, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared spectra. Hubble's orbit outside the distortion of Earth's atmosphere allows it to take extremely high-resolution images, with substantially lower background light than ground-based telescopes. Hubble has recorded some of the most detailed visible-light images ever, allowing a deep view into space and time. Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion of the universe.


One of Hubble's most famous images, "Pillars of Creation" shows stars forming in the Eagle Nebula
The HST was built by the United States space agency NASA, with contributions from the European Space Agency. The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center controls the spacecraft.
Space telescopes were proposed as early as 1923. Hubble was funded in the 1970s, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the Challenger disaster (1986). When finally launched in 1990, Hubble's main mirror was found to have been ground incorrectly, compromising the telescope's capabilities. The optics were corrected to their intended quality by a servicing mission in 1993.
Hubble is the only telescope designed to be serviced in space by astronauts. After launch by Space Shuttle Discovery in 1990, four subsequent Space Shuttle missions repaired, upgraded, and replaced systems on the telescope. A fifth mission was canceled on safety grounds following the Columbia disaster (2003). However, after spirited public discussion, NASA administrator Mike Griffin approved one final servicing mission, completed in 2009. The telescope is operating as of 2016, and could last until 2030–2040. Its scientific successor, the James Webb Space Telescope (JWST), is scheduled for launch in 2018.

The Hubble Space Telescope (HST) was put into orbit from the Space Shuttle Discovery

Quest for funding
The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established, the next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for the telescope project.
In response to this, a nationwide lobbying effort was coordinated among astronomers. Many astronomers met congressmen and senators in person, and large scale letter-writing campaigns were organized. The National Academy of Sciences published a report emphasizing the need for a space telescope, and eventually the Senate agreed to half of the budget that had originally been approved by Congress.

Grinding of Hubble's primary mirror at Perkin-Elmer, March 1979

The funding issues led to something of a reduction in the scale of the project, with the proposed mirror diameter reduced from 3 m to 2.4 m, both to cut costs  and to allow a more compact and effective configuration for the telescope hardware. A proposed precursor 1.5 m space telescope to test the systems to be used on the main satellite was dropped, and budgetary concerns also prompted collaboration with the European Space Agency. ESA agreed to provide funding and supply one of the first generation instruments for the telescope, as well as the solar cells that would power it, and staff to work on the telescope in the United States, in return for European astronomers being guaranteed at least 15% of the observing time on the telescope. Congress eventually approved funding of US$36 million for 1978, and the design of the LST began in earnest, aiming for a launch date of 1983. In 1983 the telescope was named after Edwin Hubble, who made one of the greatest scientific breakthroughs of the 20th century when he discovered that the universe is expanding.

Snow Angel S106 Nebula - Hubble Space Telescope



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