Radio communication

Marconi had born in Italy in 1874. He was privately educated. During his early years Marconi had an interest in science and electricity. At the age of 18, Marconi became a neighbor of university of Bologna physicist Aigusto Righi who had done research on Heinrich Herd’s work. Righi permitted Marconi to attend lectures at the university and also use the university laboratory and library.

In the early1890s, he began working on the idea of wireless telegraphy and began to conduct experiments on radio waves; Building much of his own equipment in the attic of his home. As no encouragement was coming from Italy government, he went to England with his mother and met the chief engineer of post office London. In 1896 his inventions of “wireless telegraphy “were demonstrated at Royal society London.

·         1897- Marconi transmitted Morse code signal over a distance of six Kms. He established a Marconi company. Wireless telegraphy was born.

·         1898- The wireless signal was transmitted on a 12 miles distance.

·         1901- He established a wireless transmission station, at Wexford, to link England and Ireland.

·         This signal was also received in Canada, where he used 150m high antenna for signal detection. The distance covered was 3500 Km. for this; the transmission wavelength used was nearly 350m (850kHzs). It was observed that during night, the signal reached farther and farther but in day time it was reduces to half the distance about 1100Kms.

·         1902- The signal crossed Atlantic.

·         1904- A commercial service was established to transmit night news summaries to ships.

·         1907- A regular Trans Atlantic radio telegraph service was begun.

·        1909-  Marconi shared Nobel Prize in physics for his radio work.

·         The company struggled to provide reliable communication to others. Long after it was apparent that the future of radio communication lay with continuous wave transmissions.

·         1915- After the introduction of the oscillating vacuum tube (valve), the first radio broad-casting began in 1920.

·         1922- Regular entertainment broadcasting service commissioned for BBC.

              

      Wireless communication

        Marconi was born into the Italian nobility as Guglielmo Giovanni Maria Marconi in Bologna on 25 April 1874,his mother being from Ireland.he was educated privately. During his early years, Marconi had an interest in science and electricity and in the early 1890s he began working on the idea of "wireless telegraphy",A relatively new development came from Heinrich Hertz, who in 1888 demonstrated that one could produce and detect electromagnetic radiation, generally referred to as radio waves.

Marconi, then twenty years old, began to conduct experiments in radio waves, building much of his own equipment in the attic of his home at the Villa Griffone in Pontecchio (now an administrative subdivision of Sasso Marconi), Italy with the help of his butler Mignani. In the summer of 1894, he built a storm alarm made up of a battery, a coherer, and an electric bell, which went off when it picked up the radio waves generated by lightning. He continued to work in the attic. Late one night in December 1894 he demonstrated a radio transmitter and receiver to his mother, a set-up that made a bell ring on the other side of the room by pushing a telegraphic button on a bench.. In 1895 he succeeded in sending wireless signals over a distance of one and half mile.

Finding little interest or appreciation for his work in Italy, Marconi travelled to London in early 1896 at the age of 21, accompanied by his mother, to seek support for his work.  While there, Marconi gained the interest and support of William Preece, the Chief Electrical Engineer of the British Post. Marconi made his first demonstration of his system for the British government in July 1896. A further series of demonstrations for the British followed—by March 1897, Marconi had transmitted Morse code signals over a distance of about 6 kilometres  across Salisbury PlainOffice. On 13 May 1897, Marconi sent the world's first ever wireless communication over open sea. The experiment, based in Wales, witnessed a message transversed over the Bristol Channel from Flat Holm Island to Lavernock Point in Penarth, a distance of 6 kilometres. The message read "Are you ready". The transmitting equipment was almost immediately relocated to Brean Down Fort on the Somerset coast, stretching the range to 16 kilometres . Impressed by these and other demonstrations, Preece introduced Marconi's ongoing work to the general public at two important London lectures: "Telegraphy without Wires", at the Toynbee Hall on 11 December 1896; and "Signaling through Space without Wires", given to the Royal Institution on 4 June 1897. In 1897 Marconi wireless Telegraph Company born.

 In December 1898, the British lightship service authorized the establishment of wireless communication between the South Foreland lighthouse at Doverand the East Goodwin lightship, twelve miles distant. On 17 March 1899 the East Goodwin lightship sent a signal on behalf of the merchant vessel Elbewhich had run aground on Goodwin Sands. The message was received by the radio operator of the South Foreland lighthouse, who summoned the aid of the Ramsgate lifeboat. In 1899 he established wireless communication between France and England across the English Channel. He was awarded a patent no 7777 for his "tuned or syntonic telegraphy".

 Marconi began investigating the means to signal completely across the Atlantic in order to compete with the transatlantic telegraph cables. Marconi established a wireless transmitting station at Marconi House, Rosslare Strand, Co. Wexford in 1901 to act as a link between Poldhu in Cornwall, England and Clifden in Co. Galway, Ireland. He soon made the announcement that the message was received at Signal Hill in St John's, Newfoundland (now part of Canada) on 12 December 1901, using a 500-foot (150 m) kite-supported antenna for reception—signals transmitted by the company's new high-power station at Poldhu, Cornwall. The distance between the two points was about 2,200 miles (3,500 km). The exact wavelength used is not known, but it is fairly reliably determined to have been in the neighbourhood of 350 meters (frequency ≈850 kHz). 

Marconi prepared a better organized and documented test. In February 1902, the SS Philadelphia sailed west from Great Britain with Marconi aboard, carefully recording signals sent daily from the Poldhu station. The test results produced coherer-tape reception up to 1,550 miles (2,490 km), and audio reception up to 2,100 miles (3,400 km). The maximum distances were achieved at night, and these tests were the first to show that radio signals for medium wave and longwave transmissions travel much farther at night than in the day. During the daytime, signals had been received up to only about 700 miles (1,100 km), less than half of the distance claimed earlier at Newfoundland, where the transmissions had also taken place during the day.

On 17 December 1902, a transmission from the Marconi station in Glace Bay, Nova Scotia, Canada became the world's first radio message to cross the Atlantic from North America. In 1901, Marconi built a station near South Wellfleet, Massachusetts that sent a message of greetings on 18 January 1903 from United States President Theodore Roosevelt to King Edward VII of the United Kingdom. However, consistent transatlantic signalling was difficult to establish.

In 1904, a commercial service was established to transmit nightly news summaries to subscribing ships, which could incorporate them into their on-board newspapers. A regular transatlantic radio-telegraph service was finally begun on 17 October 1907 between Clifden, Ireland and Glace Bay, but even after this the company struggled for many years to provide reliable communication to others.

Over the years, the Marconi companies gained a reputation for being technically conservative, in particular by continuing to use inefficient spark-transmitter technology, which could be used only for radio-telegraph operations, long after it was apparent that the future of radio communication lay with continuous-wave transmissions which were more efficient and could be used for audio transmissions. Somewhat belatedly, the company did begin significant work with continuous-wave equipment beginning in 1915, after the introduction of the oscillating vacuum tube (valve). The New Street Works factory in Chelmsford was the location for the first entertainment radio broadcasts in the United Kingdom in 1920, employing a vacuum tube transmitter and featuring Dame Nellie Melba. In 1922, regular entertainment broadcasts commenced from the Marconi Research Centre at Great Baddow, forming the prelude to the BBC, and he spoke of the close association of aviation and wireless telephony in that same year at a private gathering with Florence Tyzack Parbury, and even spoke of interplanetary wireless communication.

Born in Bologna, Italy, in 1874, Guglielmo Marconi was a Nobel Prize-winning physicist and inventor credited with the groundbreaking work necessary for all future radio technology. Through his experiments in wireless telegraphy, Marconi developed the first effective system of radio communication.

In 1914, Marconi was made a Senator in the Italian Senate and appointed Honorary Knight Grand Cross of the Royal Victorian Orderin the UK. During World War I, Italy joined the Allied side of the conflict, and Marconi was placed in charge of the Italian military's radio service. He attained the rank of lieutenant in the Italian Army and of commander in the Italian Navy. In 1929, he was made a marquess by King Victor Emmanuel III.

Italian inventor and engineer Guglielmo Marconi (1874-1937) developed, demonstrated and marketed the first successful long-distance wireless telegraph and in 1901 broadcast the first transatlantic radio signal. His company’s Marconi radios ended the isolation of ocean travel and saved hundreds of lives, including all of the surviving passengers from the sinking Titanic. In 1909 he shared the Nobel Prize in Physics for his radio work.

Goodbye to Sparks

By the late 1920s most radio transmitters were using vacuum tubes rather than sparks to generate radio waves. And then the vacuum tubes were abandoned in favor of transistors.

Scientists and engineers have continued to innovate quickly in the field of radio technology. Radio, television, satellite communications, mobile phones, radar, and many other inventions and gadgets have made Hertz’s discovery an indispensable part of modern life.

Crystal detectors.

A natural mineral crystal forms the semiconductor side of the junction. The most common crystal used was galena (PbS, lead sulfide), a naturally occurring ore of lead, although many other minerals were also used including silicon, iron pyrite, molybdenite and carborundum.[3] Galena is a semiconductor with a small bandgap of about 0.4 eV and is used without treatment directly as it is mined.

Historically, many other minerals and compounds besides galena were used for the crystal, the most important being iron pyrite ("fool's gold", iron disulfide, FeS2), silicon, molybdenite (MoS2), and silicon carbide (carborundum, SiC). Some of these other junctions, particularly carborundum, were stable enough that they were equipped with a more permanent spring-loaded contact rather than a cat's whisker.[7] For this reason, carborundum detectors were preferred for use in large commercial wireless stations and military and shipboard stations that were subject to vibration from waves and gunnery exercises. Carborundum detectors, which used large-area contacts, were also particularly robust in this regard. To increase sensitivity, some of these junctions such as silicon carbide were biased by connecting a battery and potentiometer across them to provide a small constant forward voltage across the junction. Later, when AM radio transmission was developed to transmit sound, around World War I, crystal detectors proved able to receive this transmission as well.

After about 1920, receivers using crystal detectors were largely superseded by the first amplifying receivers, which used vacuum tubes. These did not require the fussy adjustments that crystals required, were more sensitive, and also were powerful enough to drive loudspeakers. The point-contact semiconductor detector was subsequently resurrected around World War II because of the military requirement for microwave radardetectors. Vacuum-tube detectors do not work at microwave frequencies Silicon and germanium point-contact diodes were developed. Wartime research on p-n junctions in crystals paved the way for the invention of the point-contact transistor in 1947.The germanium diodes that became widely available after the war proved to be as sensitive as galena and did not require any adjustment, so germanium diodes replaced cat's-whisker detectors in the few crystal radios still being made, largely putting an end to the manufacture of this antique radio component.

De Forest quickly refined his device into the triode, which became the basis of long-distance telephone and radio communications, radars, and early digital computers for 50 years, until the advent of the transistor in the 1960s.

 In 1915, AT&T used the innovation to conduct the first transcontinental telephone calls, in conjunction with the Panama-Pacific International Exposition at San Francisco. In October, 1915 AT&T conducted test radio transmissions from the Navy's station in Arlington, Virginia that were heard as far away as Paris and Hawaii.

Beginning in 1913 Armstrong prepared papers and gave demonstrations that comprehensively documented how to employ three-element vacuum tubes in circuits that amplified signals to stronger levels than previously thought possible, and that could also generate high-power oscillations usable for radio transmission. In late 1913 Armstrong applied for patents covering the regenerative circuit, and on October 6, 1914 U.S. patent 1,113,149 was issued for his discovery.

Electromagnetic wave equations

Where 

 is a vector differential operator.

From the start, Maxwell’s theory was the most elegant of all… the fundamental hypothesis of Maxwell’s theory contradicted the usual views, and was not supported by evidence from decisive experiments.”

Producing and Detecting Radio Waves

In November 1886 Hertz constructed the apparatus shown below.

The Oscillator. At the ends are two hollow zinc spheres of diameter 30 cm. The spheres are each connected to copper wires which run into the middle where there is a gap for sparks to jump between.

He applied high voltage a.c. electricity across the central spark-gap, creating sparks.

The sparks caused violent pulses of electric current within the copper wires. These pulses reverberated within the wires, surging back and forth at a rate of roughly 100 million per second.

As Maxwell had predicted, the oscillating electric charges produced electromagnetic waves – radio waves – which spread out through the air around the wires. Some of the waves reached a loop of copper wire 1.5 meters away, producing surges of electric current within it. These surges caused sparks to jump across a spark-gap in the loop

This was an experimental triumph. Hertz had produced and detected radio waves. He had passed electrical energy through the air from one device to another one located over a meter away. Over the next three years, in a series of brilliant experiments, Hertz fully verified Maxwell’s theory. He proved beyond doubt that his apparatus was producing electromagnetic waves, demonstrating that the energy radiating from his electrical oscillators could be reflected, refracted, produce interference patterns, and produce standing waves just like light. No connecting wires were needed. 

Strangely, though, Hertz did not appreciate the monumental practical importance of the electromagnetic waves he had produced.  He said “I do not think that the wireless waves I have discovered will have any practical application.”

The waves Hertz first generated in November 1886 quickly changed the world.

By 1896 Guglielmo Marconi had applied for a patent for wireless communications. By 1901 he had transmitted a wireless signal across the Atlantic Ocean from Britain to Canada.

Scientists and non-scientists alike owe a lot to Heinrich Hertz. At the age of 35 Hertz became very ill, suffering severe migraines. Heinrich Rudolf Hertz died aged 36 in Bonn on January 1, 1894 of blood-vessel inflammation resulting from immune system problems.

“An electric spark generates electro-magnetic radiation.” A circular coil placed away from the source, can receive these signals at a distance. An induction coil can generate Alternating Current, from a Direct Current source. Therefore the secondary of induction coil can be used to generate sparks (signal). Marconi built his wireless telegraphy on these principles.

Modern chemistry

A decisive moment came when 'chemistry' was distinguished from alchemy by Robert Boyle in his work The Sceptical Chymist, in 1661.Other important steps included the gravimetric experimental practices of medical chemists like William Cullen, Joseph Black, Torbern Bergman and Pierre Macquer and through the work of Antoine Lavoisier(Father of Modern Chemistry) on oxygen and the law of conservation of mass, which refuted phlogiston theory. The theory that all matter is made of atoms, which are the smallest constituents of matter that cannot be broken down without losing the basic chemical and physical properties of that matter, was provided by John Dalton in 1803. In 1869, Dmitri Mendeleev composed his periodic table of elements on the basis of Dalton's discoveries.

The synthesis of urea by Friedrich Wöhler opened a new research field, organic chemistry, and by the end of the 19th century, scientists were able to synthesize hundreds of organic compound. The 20th century also saw the integration of physics and chemistry, with chemical properties explained as the result of the electronic structure of the atom. Linus Pauling's book on The Nature of the Chemical Bond used the principles of quantum mechanics to deduce bond angles in ever-more complicated Pauling's work culminated in the physical modelling of DNA, the secret of life.

Midway through the 19th century, the focus of geology shifted from description and classification to attempts to understand how the surface of the Earth had changed. Geologists' embrace of plate tectonics became part of a broadening of the field from a study of rocks into a study of the Earth as a planet.

Antoine-Laurent de Lavoisier  was a French nobleman and chemist who was central to the 18th-century chemical revolution and who had a large influence on both the history of chemistry and the history of biology. He is widely considered in popular literature as the "father of modern chemistry".
It is generally accepted that Lavoisier's great accomplishments in chemistry largely stem from his changing the science from a qualitative to a quantitative one. Lavoisier is most noted for his discovery of the role oxygen plays in combustion. He recognized and named oxygen (1778) and hydrogen (1783) and opposed the phlogiston theory. Lavoisier helped construct the metric system, wrote the first extensive list of elements, and helped to reform chemical nomenclature. He predicted the existence of silicon (1787) and was also the first to establish that sulfur was an element (1777) rather than a compound. He discovered that, although matter may change its form or shape, its mass always remains the same.

Oxygen theory of combustion

.

During late 1772 Lavoisier turned his attention to the phenomenon of combustion, the topic on which he was to make his most significant contribution to science. He reported the results of his first experiments on combustion in a note to the Academy on 20 October, in which he reported that when phosphorus burned, it combined with a large quantity of air to produce acid spirit of phosphorus, and that the phosphorus increased in weight on burning. In a second sealed note deposited with the Academy a few weeks later (1 November) Lavoisier extended his observations and conclusions to the burning of sulfur and went on to add that "what is observed in the combustion of sulfur and phosphorus may well take place in the case of all substances that gain in weight by combustion and calcination: and I am persuaded that the increase in weight of metallic calces is due to the same cause."

Joseph Black's "fixed air"

During 1773 Lavoisier determined to review thoroughly the literature on air, particularly "fixed air," and to repeat many of the experiments of other workers in the field. He published an account of this review in 1774 in a book entitled Physical and Chemical Essays. In the course of this review he made his first full study of the work of Joseph Black, the Scottish chemist who had carried out a series of classic quantitative experiments on the mild and caustic alkalies. Black had shown that the difference between a mild alkali, for example, chalk (CaCO₃), and the caustic form, for example, quicklime (CaO), lay in the fact that the former contained "fixed air," not common air fixed in the chalk, but a distinct chemical species, now understood to be carbon dioxide (CO₂), which was a constituent of the atmosphere. Lavoisier recognized that Black's fixed air was identical with the air evolved when metal calces were reduced with the charcoal and even suggested that the air which combined with metals on calcination and increased the weight might be Black's fixed air, that is, CO₂.

Joseph Priestley

Joseph Priestley, an English chemist known for isolating oxygen, which he termed "dephlogisticated air."

In the spring of 1774 Lavoisier carried out experiments on the calcination of tin and lead in sealed vessels which conclusively confirmed that the increase in weight of metals in combustion was due to combination with air. But the question remained about whether it was combination with common atmospheric air or with only a part of atmospheric air. In October the English chemist Joseph Priestley visited Paris, where he met Lavoisier and told him of the air which he had produced by heating the red calx of mercury with a burning glass and which had supported combustion with extreme vigor. Priestley at this time was unsure of the nature of this gas, but he felt that it was an especially pure form of common air. Lavoisier carried out his own researches on this peculiar substance. The result was his famous memoir On the Nature of the Principle Which Combines with Metals during Their Calcination and Increases Their Weight, read to the Academy on 26 April 1775. In the original memoir Lavoisier showed that the mercury calx was a true metallic calx in that it could be reduced with charcoal, giving off Black's fixed air in the process. When reduced without charcoal, it gave off an air which supported respiration and combustion in an enhanced way. He concluded that this was just a pure form of common air, and that it was the air itself "undivided, without alteration, without decomposition" which combined with metals on calcination.
After returning from Paris, Priestley took up once again his investigation of the air from mercury calx. His results now showed that this air was not just an especially pure form of common air but was "five or six times better than common air, for the purpose of respiration, inflammation, and ... every other use of common air." He called the air dephlogisticated air, as he thought it was common air deprived of its phlogiston. Since it was therefore in a state to absorb a much greater quantity of phlogiston given off by burning bodies and respiring animals, the greatly enhanced combustion of substances and the greater ease of breathing in this air were explained

Pioneer of stoichiometry

Lavoisier's researches included some of the first truly quantitative chemical experiments. He carefully weighed the reactants and products of a chemical reaction in a sealed glass vessel so that no gases could escape, which was a crucial step in the advancement of chemistry.In 1774, he showed that, although matter can change its state in a chemical reaction, the total mass of matter is the same at the end as at the beginning of every chemical change. Thus, for instance, if a piece of wood is burned to ashes, the total mass remains unchanged if gaseous reactants and products are included. Lavoisier's experiments supported the law of conservation of mass. In France it is taught as Lavoisier's Law and is paraphrased from a statement in his "Nothing is lost, nothing is created, everything is transformed. Mikhail Lomonosov (1711–1765) had previously expressed similar ideas in 1748 and proved them in experiments; others whose ideas pre-date the work of Lavoisier include Jean Rey (1583–1645), Joseph Black (1728–1799), and Henry Cavendish (1731–1810).

Modern Chemistry (20th Century Chemistry) - Mid 19th Century to Present; This is the era chemistry flourished. Lavoisier's thesis gave chemists the first sound understanding of the nature of chemical reactions. Lavoisier's work led an English school teacher by the name of John Dalton to formulate his atomic theory. Around the same time an Italian chemist, Amedeo Avogadro formulated his own theory (Avogadro's Law) concerning molecules and their relation to temperature and pressure.  By the middle of the 19th century, there were approximately 60 known elements. John A.R. Newlands, Stanislao Cannizzaro and A.E.B. de Chancourtois first noticed that all of these elements were very much alike in structure. Their work led Dmitri Mendeleev to publish the first periodic table.  Mendeleev's work set the foundation of theoretical chemistry. In 1896 Henri Becquerel and the Curies discovered the phenomenon known as radioactivity. This laid the foundation for nuclear chemistry. In 1919, Ernest Rutherford became discovered that elements could be transmutated. Rutherford's work laid the basis for interpreting the structure of the atom. Soon after, another chemist, Niels Bohr finalized the atomic theory. These and other major advanced in chemistry have led to many distinct branches of chemistry. These branches include, but are not limited to: biochemistry, nuclear chemistry, chemical engineering, organic chemistry.

Rare Earth Elements

Monazite is a rare phosphate mineral with a chemical composition of (Ce,La,Nd,Th)(PO4,SiO4). It usually occurs in small isolated grains, as an accessory mineral in igneous and metamorphic rocks such as granite, pegmatite, schist, and gneiss. These grains are resistant to weathering and become concentrated in soils and sediments downslope from the host rock. When in high enough concentrations, they are mined for their rare earth and thorium content.

Monazite Mineral Group
Mineral	Chemical Composition
Brabantite	CaTh(PO4)2
Cheralite	(Ca,Ce,Th)(P,Si)O4
Gasparite-(Ce)	(Ce,La,Nd)AsO4
Monazite-(Ce)	CePO4
Monazite-(La)	LaPO4
Monazite-(Nd)	NdPO4
Monazite-(Sm)	SmPO4
Rooseveltite	BiAsO4

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            Monazite is a yellowish brown to reddish brown or greenish brown mineral with a resinous to vitreous luster

Monazite is known more for where it accumulates instead of where it forms. It forms during the crystallization of igneous rocks and during the metamorphism of clastic sedimentary rocks. When these rocks weather, monazite is one of the more resistant minerals and becomes concentrated in the weathering debris. The soils and sediments found near a weathering outcrop can have a higher concentration of monazite than the source rock.
The liberated grains of monazite then begin a journey downslope. Eventually they are brought to a stream or a dry wash. There, the actions of gravity and running water help the heavy grains of monazite and other heavy minerals segregate from lighter minerals. They accumulate behind boulders, on the inside bends of stream channels and work their way down into the lower portions of the sediment deposit. Some are washed to the sea where they accumulate in deltaic, beach, or shallow water sediments.

Today, most of the world's monazite is produced in the offshore waters of India, Malaysia, Vietnam, and Brazil. Southern India and Sri Lanka have the most extensive offshore monazite resources known. Australia was once the world's largest producer of monazite and is thought to have the world's largest monazite resource. It has not been a significant producer since the 1990s, after public objection shut down mining on Frasier IslandRare earth elements play an essential role in our national defense. The military uses night-vision goggles, precision-guided weapons, communications equipment, GPS equipment, batteries, and other defense electronics. These give the United States military an enormous advantage. Rare earth metals are key ingredients for making the very hard alloys used in armored vehicles and projectiles that shatter upon impact.

Before 1965 there was relatively little demand for rare earth elements. At that time, most of the world's supply was being produced from placer deposits in India and Brazil. In the 1950s, South Africa became the leading producer from rare earth bearing monazite deposits. At that time, the Mountain Pass Mine in California was producing minor amounts of rare earth oxides from a Precambrian carbonatite.

The demand for rare earth elements saw its first explosion in the mid-1960s, as the first color television sets were entering the market. Europium was the essential material for producing the color images. The Mountain Pass Mine began producing europium from bastnasite, which contained about 0.1% europium. This effort made the Mountain Pass Mine the largest rare earth producer in the world and placed the United States as the leading producer.

"Rare earths are relatively abundant in the Earth's crust, but discovered minable concentrations are less common than for most other ores. U.S. and world resources are contained primarily in bastnäsite and monazite. Bastnäsite deposits in China and the United States constitute the largest percentage of the world's rare-earth economic resources, while monazite deposits in Australia, Brazil, China, India, Malaysia, South Africa, Sri Lanka, Thailand, and the United States constitute the second largest segment.

The scientific revolution 

The scientific revolution is a concept used by historians to describe the emergence of modern science during the early modern period, when developments in mathematics, physics, astronomy, biology (including human anatomy) and chemistry transformed the views of society about nature.  While its dates are debated, the publication in 1543 of Nicolaus Copernicus's De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) is often cited as marking the beginning of the scientific revolution.The beginning of the scientific revolution, the Scientific Renaissance, was focused on the recovery of the knowledge of the ancients; this is generally considered to have ended in 1632 with publication of Galileo's Dialogue Concerning the Two Chief World Systems.^[8] The completion of the scientific revolution is attributed to the "grand synthesis" of Isaac Newton's 1687 Principia, that formulated the laws of motion and universal gravitation, and completed the synthesis of a new cosmology.

Great advances in science have been termed "revolutions" since the 18th century. In 1747, Clairaut wrote that "Newton was said in his own lifetime to have created a revolution".^[10] The word was also used in the preface to Lavoisier's 1789 work announcing the discovery of oxygen. "Few revolutions in science have immediately excited so much general notice as the introduction of the theory of oxygen ... Lavoisier saw his theory accepted by all the most eminent men of his time, and established over a great part of Europe within a few years from its first promulgation.

"A new view of nature emerged, replacing the Greek view that had dominated science for almost 2,000 years. Science became an autonomous discipline, distinct from both philosophy and technology and came to be regarded as having utilitarian goals. The scientific revolution is traditionally assumed to start with the Copernican Revolution (initiated in 1543) and to be complete in the "grand synthesis" of Isaac Newton's 1687 Principia. Much of the change of attitude came from Francis Baconwhose "confident and emphatic announcement" in the modern progress of science inspired the creation of scientific societies such as the Royal Society, and Galileo who championed Copernicus and developed the science of motion.

Rapid accumulation of knowledge, which has characterized the development of science since the 17th century, had never occurred before that time. The new kind of scientific activity emerged only in a few countries of Western Europe, and it was restricted to that small area for about two hundred years.

It is also true that many of the important figures of the scientific revolution shared in the general Renaissance respect for ancient learning and cited ancient pedigrees for their innovations. Nicolaus Copernicus (1473–1543),^[25] Kepler (1571–1630),^[26] Newton (1642–1727),^[27] and Galileo Galilei (1564–1642)^{[1][2][3][28]} all traced different ancient and medieval ancestries for the heliocentric system. In the Axioms Scholium of his Principia, Newton said its axiomatic three laws of motion were already accepted by mathematicians such as Huygens (1629–1695), Wallace, Wren and others. While preparing a revised edition of his Principia, Newton attributed his law of gravity and his first law of motion to a range of historical figures.

By the end of the scientific revolution the qualitative world of book-reading philosophers had been changed into a mechanical, mathematical world to be known through experimental research. Though it is certainly not true that Newtonian science was like modern science in all respects, it conceptually resembled ours in many ways. Many of the hallmarks of modern science, especially with regard to its institutionalization and professionalization, did not become standard until the mid-19th century.

The term British empiricism came into use to describe philosophical differences perceived between two of its founders Francis Bacon, described as empiricist, and René Descartes, who was described as a rationalist. Thomas Hobbes, George Berkeley, and David Hume were the philosophy's primary exponents, who developed a sophisticated empirical tradition as the basis of human knowledge.

Bacon proposed a great reformation of all process of knowledge for the advancement of learning divine and human, which he called Instauratio Magna (The Great Instauration). For Bacon, this reformation would lead to a great advancement in science and a progeny of new inventions that would relieve mankind's miseries and needs. Bacon considered that it is of greatest importance to science not to keep doing intellectual discussions or seeking merely contemplative aims, but that it should work for the bettering of mankind's life by bringing forth new inventions, having even stated that "inventions are also, as it were, new creations and imitations of divine works".^{[35][page needed]} He explored the far-reaching and world-changing character of inventions, such as the printing press, gunpowder and the compass.

Galileo Galilei has been called the "father of modern observational astronomy",^[42] the "father of modern physics",^[43][44] the "father of science",^[44][45] and "the Father of Modern Science".^[46] His original contributions to the science of motion were made through an innovative combination of experiment and mathematics.  his work marked another step towards the eventual separation of science from both philosophy and religion; a major development in human thought. He was often willing to change his views in accordance with observation. In order to perform his experiments, Galileo had to set up standards of length and time, so that measurements made on different days and in different laboratories could be compared in a reproducible fashion. This provided a reliable foundation on which to confirm mathematical laws using inductive reasoning.

Galileo showed a remarkably modern appreciation for the proper relationship between mathematics, theoretical physics, and experimental physics. He understood the parabola, both in terms of conic sections and in terms of the ordinate (y) varying as the square of the abscissa (x). Galilei further asserted that the parabola was the theoretically ideal trajectory of a uniformly accelerated projectile in the absence of friction and other disturbances. He conceded that there are limits to the validity of this theory, noting on theoretical grounds that a projectile trajectory of a size comparable to that of the Earth could not possibly be a parabola,^[50] but he nevertheless maintained that for distances up to the range of the artillery of his day, the deviation of a projectile's trajectory from a parabola would be only very slight.

 Gravity, interpreted as an innate attraction between every pair of particles of matter, was an occult quality in the same sense as the scholastics' "tendency to fall" had been.... By the mid eighteenth century that interpretation had been almost universally accepted, and the result was a genuine reversion (which is not the same as a retrogression) to a scholastic standard. Innate attractions and repulsions joined size, shape, position and motion as physically irreducible primary properties of matter.

The French established the Academy of Sciences in 1666. In contrast to the private origins of its British counterpart, the Academy was founded as a government body by Jean-Baptiste Colbert. Its rules were set down in 1699 by King Louis XIV, when it received the name of 'Royal Academy of Sciences' and was installed in the Louvre in Paris.

Practical attempts to improve the refining of ores and their extraction to smelt metals was an important source of information for early chemists in the 16th century, among them Georg Agricola (1494–1555), who published his great work De re metallica in 1556.^[82] His work describes the highly developed and complex processes of mining metal ores, metal extraction and metallurgy of the time. His approach removed the mysticism associated with the subject, creating the practical base upon which others could build.

English chemist Robert Boyle (1627–1691) is considered to have refined the modern scientific method for alchemy and to have separated chemistry further from alchemy.^[84] Although his research clearly has its roots in the alchemical tradition, Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of modern chemistry, and one of the pioneers of modern experimental scientific method. Although Boyle was not the original discover, he is best known for Boyle's law, which he presented in 1662:^[85] the law describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system. Importantly, he advocated a rigorous approach to scientific experiment: he believed all theories must be tested experimentally before being regarded as true. The work contains some of the earliest modern ideas of atoms, molecules, and chemical reaction, and marks the beginning of the history of modern chemistry. Robert Boyle also worked frequently at the new science of electricity, and added several substances to Gilbert's list of electrics. He left a detailed account of his researches under the title of Experiments on the Origin of Electricity.^[92] Boyle, in 1675, stated that electric attraction and repulsion can act across a vacuum. One of his important discoveries was that electrified bodies in a vacuum would attract light substances, this indicating that the electrical effect did not depend upon the air as a medium. He also added resin to the then known list of electrics.

John Napier introduced logarithms as a powerful mathematical tool. With the help of the prominent mathematician Henry Briggstheir logarithmic tables embodied a computational advance that made calculations by hand much quicker.^[97] His Napier's bones used a set of numbered rods as a multiplication tool using the system of lattice multiplication. The way was opened to later scientific advances, particularly in astronomy and dynamics.

Abraham Darby I (1678–1717) was the first, and most famous, of three generations of the Darby family who played an important role in the Industrial Revolution. He developed a method of producing high-grade iron in a blast furnace fueled by coke rather than charcoal. This was a major step forward in the production of iron as a raw material for the Industrial Revolution.

Evangelista Torricelli (1607–1647) was best known for his invention of the mercury barometer. The motivation for the invention was to improve on the suction pumps that were used to raise water out of the mines. Torricelli constructed a sealed tube filled with mercury, set vertically into a basin of the same substance. The column of mercury fell downwards, leaving a Torricellian vacuum above.