1.
Bern
–
The city of Bern or Berne is the de facto capital of Switzerland, referred to by the Swiss as their Bundesstadt, or federal city. With a population of 141,762, Bern is the fourth-most populous city in Switzerland, the Bern agglomeration, which includes 36 municipalities, had a population of 406,900 in 2014. The metropolitan area had a population of 660,000 in 2000, Bern is also the capital of the canton of Bern, the second-most populous of Switzerlands cantons. The official language in Bern is German, but the language is an Alemannic Swiss German dialect. In 1983, the old town in the centre of Bern became a UNESCO World Heritage Site. Bern is ranked among the top ten cities for the best quality of life. The etymology of the name Bern is uncertain and it has long been considered likely that the city was named after the Italian city of Verona, which at the time was known as Bern in Middle High German. As a result of the find of the Bern zinc tablet in the 1980s, it is now common to assume that the city was named after a pre-existing toponym of Celtic origin. The bear was the animal of the seal and coat of arms of Bern from at least the 1220s. The earliest reference to the keeping of bears in the Bärengraben dates to the 1440s. No archaeological evidence that indicates a settlement on the site of city centre prior to the 12th century has been found so far. In antiquity, a Celtic oppidum stood on the Engehalbinsel north of Bern, fortified since the second century BC, during the Roman era, a Gallo-Roman vicus was on the same site. The Bern zinc tablet has the name Brenodor, in the Early Middle Ages, a settlement in Bümpliz, now a city district of Bern, was some 4 km from the medieval city. The medieval city is a foundation of the Zähringer ruling family, according to 14th-century historiography, Bern was founded in 1191 by Berthold V, Duke of Zähringen. In 1218, after Berthold died without an heir, Bern was made an imperial city by the Goldene Handfeste of Holy Roman Emperor Frederick II. In 1353, Bern joined the Swiss Confederacy, becoming one of the eight cantons of the period of 1353 to 1481. The city grew out towards the west of the boundaries of the peninsula formed by the river Aare, the Zytglogge tower marked the western boundary of the city from 1191 until 1256, when the Käfigturm took over this role until 1345. It was, in turn, succeeded by the Christoffelturm until 1622, during the time of the Thirty Years War, two new fortifications – the so-called big and small Schanze – were built to protect the whole area of the peninsula
Bern
–
The construction of the Untertor-bridge in Bern, Tschachtlanchronik, late 15th century
Bern
–
Aerial view of the
Old City
Bern
–
Bern in 1638
Bern
–
View of Bern from the
ISS. The Old City is in the lower, right hand side.
2.
Gotthard railway
–
The Gotthard railway is the Swiss trans-alpine railway line from northern Switzerland to the canton of Ticino. The line forms a part of an important international railway link between northern and southern Europe, especially on the Rotterdam-Basel-Genoa corridor. The Gotthard Railway Company was the private railway company which financed the construction of, and originally operated. The railway comprises a main line from Immensee to Chiasso, together with branches, from Immensee to Lucerne and Rotkreuz, from Arth-Goldau to Zug, and from Bellinzona to Locarno and Luino. The main line, second highest standard railway in Switzerland, penetrates the Alps by means of the Gotthard Tunnel at 1,151 metres above sea level. The line then descends as far as Bellinzona, at 241 metres above sea level, before climbing again to the pass of Monte Ceneri, on the way to Lugano and Chiasso. The extreme differences in altitude necessitate the use of long ramped approaches on each side, construction of the line started in 1872, with some lowland sections opening by 1874. The full line opened in 1882, following completion of the Gotthard Tunnel, the line was incorporated into the Swiss Federal Railways in 1909, and electrified in 1922. By the early years of the 1870s, northern Switzerland possessed a significant network of railways, with links to the railways of Germany. To the west, a line had reached Brigue, in the upper Rhone valley, in the centre north, lines linked Olten, Lucerne, Zug and Zurich. The selected route was an ancient one, that had used by pilgrims. Treaties for the construction of the line were made with the Kingdom of Italy, in 1869, the Gotthard Railway Company was incorporated in Lucerne in 1871. The Italian government eventually contributed £2.25 million, with Switzerland, construction of the Gotthard railway started in 1872, and the first lowland sections from Biasca to Locarno and Lugano to Chiasso were opened by 1874. The whole line was inaugurated with festivities in Lucerne and Chiasso from 21 May to 25 May 1882, scheduled operation started on 1 June. At the time, the 15, 003-metre-long Gotthard Rail Tunnel was the worlds longest rail tunnel, soon after construction, the line was secured by the army with fortresses and ways to block the tunnel in case of an invasion. At the same time the Aargauische Südbahn completed the section from Rotkreuz to Immensee, the additional feeder lines from Lucerne to Immensee, and from Zug to Arth-Goldau were completed in 1887. The Gotthard Railway Company worked the Gotthard railway until 1909, when it became part of the Swiss Federal Railways and this was seven years after the creation of that state owned railway, and the Gotthard railway was the last major railway to be absorbed. In 1922, the line was electrified by Brown, Boveri & Cie with 15 kV 16 2⁄3 Hz AC supplied by overhead line
Gotthard railway
–
Longitudinal profile of Gotthardbahn incl. branchlines.
Gotthard railway
–
Map of the Gotthard railway
Gotthard railway
–
Contemporary drawing showing a construction locomotive
Gotthard railway
–
Lower Ticino Bridge during construction phase, with its original single beam truss structure.
3.
Telegraph
–
Telegraphy is the long-distance transmission of textual or symbolic messages without the physical exchange of an object bearing the message. Thus semaphore is a method of telegraphy, whereas pigeon post is not, telegraphy requires that the method used for encoding the message be known to both sender and receiver. Such methods are designed according to the limits of the medium used. The use of signals, beacons, reflected light signals. In the 19th century, the harnessing of electricity led to the invention of electrical telegraphy, the advent of radio in the early 20th century brought about radiotelegraphy and other forms of wireless telegraphy. The word telegraph was first coined by the French inventor of the Semaphore line, Claude Chappe, a telegraph is a device for transmitting and receiving messages over long distances, i. e. for telegraphy. The word telegraph alone now generally refers to an electrical telegraph, Wireless telegraphy is also known as CW, for continuous wave, as opposed to the earlier radio technique of using a spark gap. Contrary to the definition used by Chappe, Morse argued that the term telegraph can strictly be applied only to systems that transmit. This is to be distinguished from semaphore, which transmits messages. Smoke signals, for instance, are to be considered semaphore, according to Morse, telegraph dates only from 1832 when Pavel Schilling invented one of the earliest electrical telegraphs. A telegraph message sent by a telegraph operator or telegrapher using Morse code was known as a telegram. A cablegram was a sent by a submarine telegraph cable. Later, a Telex was a sent by a Telex network. A wire picture or wire photo was a picture that was sent from a remote location by a facsimile telegraph. A diplomatic telegram, also known as a cable, is the term given to a confidential communication between a diplomatic mission and the foreign ministry of its parent country. These continue to be called telegrams or cables regardless of the used for transmission. Commercial electrical telegraphs were introduced from 1837, the first telegraphs came in the form of optical telegraph, including the use of smoke signals, beacons, or reflected light, which have existed since ancient times. Early proposals for a telegraph system were made to the Royal Society by Robert Hooke in 1684 and were first implemented on an experimental level by Sir Richard Lovell Edgeworth in 1767
Telegraph
–
Replica of
Claude Chappe 's optical telegraph on the Litermont near
Nalbach, Germany
Telegraph
–
Demonstration of the semaphore
Telegraph
–
Pavel Schilling, an early pioneer of electrical telegraphy
Telegraph
–
Cooke and Wheatstone's five-needle, six-wire telegraph
4.
Signal (information theory)
–
A signal as referred to in communication systems, signal processing, and electrical engineering is a function that conveys information about the behavior or attributes of some phenomenon. The IEEE Transactions on Signal Processing states that the signal includes audio, video, speech, image, communication, geophysical, sonar, radar. Typically, signals are provided by a sensor, and often the form of a signal is converted to another form of energy using a transducer. For example, a microphone converts a signal to a voltage waveform. The formal study of the content of signals is the field of information theory. The information in a signal is accompanied by noise. The term noise usually means an undesirable random disturbance, but is extended to include unwanted signals conflicting with the desired signal. The prevention of noise is covered in part under the heading of signal integrity, the separation of desired signals from a background is the field of signal recovery, one branch of which is estimation theory, a probabilistic approach to suppressing random disturbances. Engineering disciplines such as electrical engineering have led the way in the design, study, and implementation of systems involving transmission, storage, definitions specific to sub-fields are common. For example, in theory, a signal is a codified message, that is. In the context of signal processing, arbitrary binary data streams are not considered as signals, in a communication system, a transmitter encodes a message to a signal, which is carried to a receiver by the communications channel. For example, the words Mary had a little lamb might be the message spoken into a telephone, the telephone transmitter converts the sounds into an electrical voltage signal. The signal is transmitted to the telephone by wires, at the receiver it is reconverted into sounds. In telephone networks, signalling, for example common-channel signaling, refers to number and other digital control information rather than the actual voice signal. Signals can be categorized in various ways, the most common distinction is between discrete and continuous spaces that the functions are defined over, for example discrete and continuous time domains. Discrete-time signals are often referred to as series in other fields. Continuous-time signals are often referred to as continuous signals even when the functions are not continuous. A second important distinction is between discrete-valued and continuous-valued, particularly in digital signal processing a digital signal is sometimes defined as a sequence of discrete values, that may or may not be derived from an underlying continuous-valued physical process
Signal (information theory)
–
A digital signal has two or more distinguishable waveforms, in this example, high voltage and low voltages, each of which can be mapped onto a digit. Characteristically, noise can be removed from digital signals provided it is not too large.
5.
Channel (communications)
–
A channel is used to convey an information signal, for example a digital bit stream, from one or several senders to one or several receivers. A channel has a capacity for transmitting information, often measured by its bandwidth in Hz or its data rate in bits per second. Communicating data from one location to another requires some form of pathway or medium and these pathways, called communication channels, use two types of media, cable and broadcast. Cable or wire line media use physical wires of cables to transmit data, twisted-pair wire and coaxial cables are made of copper, and fiber-optic cable is made of glass. In information theory, a channel refers to a theoretical channel model with certain error characteristics, in this more general view, a storage device is also a kind of channel, which can be sent to and received from. Examples of communications include, A connection between initiating and terminating nodes of a circuit. A single path provided by a transmission medium via either physical separation, such as by multipair cable or electrical separation, a path for conveying electrical or electromagnetic signals, usually distinguished from other parallel paths. A storage which can communicate a message over time as well as space The portion of a medium, such as a track or band. A buffer from which messages can be put and got, see Actor model and process calculi for discussion on the use of channels. In a communications system, the physical or logical link that connects a data source to a data sink, a specific radio frequency, pair or band of frequencies, usually named with a letter, number, or codeword, and often allocated by international agreement. Examples, Marine VHF radio uses some 88 channels in the VHF band for two-way FM voice communication, Channel 16, for example, is 156.800 MHz. In the US, seven additional channels, WX1 - WX7, are allocated for weather broadcasts, television channels such as North American TV Channel 2 =55.25 MHz, Channel 13 =211.25 MHz. Each channel is 6 MHz wide, besides these physical channels, television also has virtual channels. Wi-Fi consists of unlicensed channels 1-13 from 2412 MHz to 2484 MHz in 5 MHz steps, the radio channel between an amateur radio repeater and a ham uses two frequencies often 600 kHz apart. For example, a repeater that transmits on 146.94 MHz typically listens for a ham transmitting on 146.34 MHz, all of these communications channels share the property that they transfer information. The information is carried through the channel by a signal, a channel can be modelled physically by trying to calculate the physical processes which modify the transmitted signal. For example, in wireless communications the channel can be modelled by calculating the reflection off every object in the environment, a sequence of random numbers might also be added in to simulate external interference and/or electronic noise in the receiver. Statistical and physical modelling can be combined, for example, in wireless communications the channel is often modelled by a random attenuation of the transmitted signal, followed by additive noise
Channel (communications)
–
Old telephone wires are a challenging communications channel for modern digital communications.
6.
Radio
–
When radio waves strike an electrical conductor, the oscillating fields induce an alternating current in the conductor. The information in the waves can be extracted and transformed back into its original form, Radio systems need a transmitter to modulate some property of the energy produced to impress a signal on it, for example using amplitude modulation or angle modulation. Radio systems also need an antenna to convert electric currents into radio waves, an antenna can be used for both transmitting and receiving. The electrical resonance of tuned circuits in radios allow individual stations to be selected, the electromagnetic wave is intercepted by a tuned receiving antenna. Radio frequencies occupy the range from a 3 kHz to 300 GHz, a radio communication system sends signals by radio. The term radio is derived from the Latin word radius, meaning spoke of a wheel, beam of light, however, this invention would not be widely adopted. The switch to radio in place of wireless took place slowly and unevenly in the English-speaking world, the United States Navy would also play a role. Although its translation of the 1906 Berlin Convention used the terms wireless telegraph and wireless telegram, the term started to become preferred by the general public in the 1920s with the introduction of broadcasting. Radio systems used for communication have the following elements, with more than 100 years of development, each process is implemented by a wide range of methods, specialised for different communications purposes. Each system contains a transmitter, This consists of a source of electrical energy, the transmitter contains a system to modulate some property of the energy produced to impress a signal on it. This modulation might be as simple as turning the energy on and off, or altering more subtle such as amplitude, frequency, phase. Amplitude modulation of a carrier wave works by varying the strength of the signal in proportion to the information being sent. For example, changes in the strength can be used to reflect the sounds to be reproduced by a speaker. It was the used for the first audio radio transmissions. Frequency modulation varies the frequency of the carrier, the instantaneous frequency of the carrier is directly proportional to the instantaneous value of the input signal. FM has the capture effect whereby a receiver only receives the strongest signal, Digital data can be sent by shifting the carriers frequency among a set of discrete values, a technique known as frequency-shift keying. FM is commonly used at Very high frequency radio frequencies for high-fidelity broadcasts of music, analog TV sound is also broadcast using FM. Angle modulation alters the phase of the carrier wave to transmit a signal
Radio
–
The
Alexandra Palace radio transmitter mast
Radio
–
Classic radio
receiver dial
Radio
–
Rooftop
television antennas.
Yagi-Uda antennas like these six are widely used at
VHF and
UHF frequencies.
Radio
–
Bakelite radio at the Bakelite Museum, Orchard Mill, Williton, Somerset, UK.
7.
Semaphore line
–
A semaphore telegraph is a system of conveying information by means of visual signals, using towers with pivoting shutters, also known as blades or paddles. Information is encoded by the position of the elements, it is read when the shutter is in a fixed position. The most widely used system was invented in 1792 in France by Claude Chappe and they were much faster than post riders for conveying a message over long distances, and also had cheaper long-term operating costs, once constructed. Semaphore lines were a precursor of the telegraph, which would replace them half a century later, and would also be cheaper, faster. The distance that an optical telegraph can bridge is limited by geography and weather, thus, in practical use and this also prevented the optical telegraph from crossing wide expanses of water, unless a convenient island could be used for a relay station. Modern derivatives of the system include flag semaphore and the heliograph. The word semaphore was coined in 1801 by the French inventor of the line itself. He composed it from the Greek elements σῆμα, and from φορός, Chappe also coined the word telegraph. The word semaphoric was first printed in English in 1808, The newly constructed Semaphoric telegraphs, semaphore telegraphs are also called optical telegraphs, shutter telegraph chains, Chappe telegraphs or Napoleonic semaphore. Optical telegraphy dates from ancient times, in the form of hydraulic telegraphs, torches, the system was never put into practice. One of the first experiments of optical signalling was carried out by the Anglo-Irish landowner and inventor and he placed a bet with his friend, the horse racing gambler Lord Marsh, that he could transmit knowledge of the outcome of the race in just one hour. Using a network of signalling sections erected on ground, the signal would be observed from one station to the next by means of a telescope. The signal itself consisted of a pointer that could be placed into eight possible positions in 45 degree increments. A series of two such signals gave a total 64 code elements and a third signal took it up to 512 and he only returned to his idea in 1795, after hearing of Chappes system. Le système Chappe was used for military and national communications until the 1850s, during 1790–1795, at the height of the French Revolution, France needed a swift and reliable communication system to thwart the war efforts of its enemies. France was surrounded by the forces of Britain, the Netherlands, Prussia, Austria, and Spain, the cities of Marseille and Lyon were in revolt, the only advantage France held was the lack of cooperation between the allied forces due to their inadequate lines of communication. On 2 March 1791 at 11am, they sent the message “si vous réussissez, the first means used a combination of black and white panels, clocks, telescopes, and codebooks to send their message. However, in the summer of 1792 Claude was appointed Ingénieur-Télégraphiste and it was used to carry dispatches for the war between France and Austria
Semaphore line
–
A replica of one of
Chappe's semaphore towers in Nalbach, Germany
Semaphore line
–
Illustration of signaling by semaphore in 18th century France. The operators would move the semaphore arms to successive positions to spell out text messages in semaphore code, and the people in the next tower would read them.
Semaphore line
–
Demonstration of the semaphore
Semaphore line
–
A Chappe semaphore tower near
Saverne,
France
8.
Telecommunication
–
Telecommunication is the transmission of signs, signals, messages, writings, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems. Telecommunication occurs when the exchange of information between communication participants includes the use of technology and it is transmitted either electrically over physical media, such as cables, or via electromagnetic radiation. Such transmission paths are divided into communication channels which afford the advantages of multiplexing. The term is used in its plural form, telecommunications. Early means of communicating over a distance included visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, other examples of pre-modern long-distance communication included audio messages such as coded drumbeats, lung-blown horns, and loud whistles. Zworykin, John Logie Baird and Philo Farnsworth, the word telecommunication is a compound of the Greek prefix tele, meaning distant, far off, or afar, and the Latin communicare, meaning to share. Its modern use is adapted from the French, because its use was recorded in 1904 by the French engineer. Communication was first used as an English word in the late 14th century, in the Middle Ages, chains of beacons were commonly used on hilltops as a means of relaying a signal. Beacon chains suffered the drawback that they could pass a single bit of information. One notable instance of their use was during the Spanish Armada, in 1792, Claude Chappe, a French engineer, built the first fixed visual telegraphy system between Lille and Paris. However semaphore suffered from the need for skilled operators and expensive towers at intervals of ten to thirty kilometres, as a result of competition from the electrical telegraph, the last commercial line was abandoned in 1880. Homing pigeons have occasionally used throughout history by different cultures. Pigeon post is thought to have Persians roots and was used by the Romans to aid their military, frontinus said that Julius Caesar used pigeons as messengers in his conquest of Gaul. The Greeks also conveyed the names of the victors at the Olympic Games to various cities using homing pigeons, in the early 19th century, the Dutch government used the system in Java and Sumatra. And in 1849, Paul Julius Reuter started a service to fly stock prices between Aachen and Brussels, a service that operated for a year until the gap in the telegraph link was closed. Sir Charles Wheatstone and Sir William Fothergill Cooke invented the telegraph in 1837. Also, the first commercial electrical telegraph is purported to have constructed by Wheatstone and Cooke. Both inventors viewed their device as an improvement to the electromagnetic telegraph not as a new device, samuel Morse independently developed a version of the electrical telegraph that he unsuccessfully demonstrated on 2 September 1837
Telecommunication
–
A satellite communication antenna at the biggest facility for satellite communication in Raisting, Bavaria, Germany
Telecommunication
–
Visualization from the
Opte Project of the various routes through a portion of the Internet.
Telecommunication
–
A replica of one of
Chappe's semaphore towers.
Telecommunication
–
Optical fiber provides cheaper bandwidth for long distance communication.
9.
Communication
–
Communication is the act of conveying intended meanings from one entity or group to another through the use of mutually understood signs and semiotic rules. The main steps inherent to all communication are, The forming of communicative motivation or reason, transmission of the encoded message as a sequence of signals using a specific channel or medium. Noise sources such as forces and in some cases human activity begin influencing the quality of signals propagating from the sender to one or more receivers. Reception of signals and reassemblying of the message from a sequence of received signals. Decoding of the encoded message. Interpretation and making sense of the original message. The channel of communication can be visual, auditory, tactile and haptic, olfactory, electromagnetic, human communication is unique for its extensive use of abstract language. Development of civilization has been linked with progress in telecommunication. Nonverbal communication describes the process of conveying information in the form of non-linguistic representations, examples of nonverbal communication include haptic communication, chronemic communication, gestures, body language, facial expressions, eye contact, and how one dresses. Nonverbal communication also relates to intent of a message, examples of intent are voluntary, intentional movements like shaking a hand or winking, as well as involuntary, such as sweating. Speech also contains nonverbal elements known as paralanguage, e. g. rhythm, intonation, tempo and it affects communication most at the subconscious level and establishes trust. Likewise, written texts include nonverbal elements such as handwriting style, spatial arrangement of words, Nonverbal communication demonstrates one of Wazlawicks laws, you cannot not communicate. Once proximity has formed awareness, living creatures begin interpreting any signals received, Nonverbal cues are heavily relied on to express communication and to interpret others’ communication and can replace or substitute verbal messages. There are several reasons as to why non-verbal communication plays a role in communication. Written communication can also have non-verbal attributes, e-mails and web chats allow individual’s the option to change text font colours, stationary, emoticons, and capitalization in order to capture non-verbal cues into a verbal medium. Many different non-verbal channels are engaged at the time in communication acts. “Non-verbal behaviours may form a language system. ”Smiling, crying, pointing, caressing. Such non-verbal signals allow the most basic form of communication when verbal communication is not effective due to language barriers, Verbal communication is the spoken or written conveyance of a message
Communication
–
Communication major dimensions scheme
Communication
–
Shannon and Weaver Model of Communication
Communication
–
Berlo's Sender-Message-Channel-Receiver Model of Communication
Communication
–
Transactional model of communication
10.
Electric spark
–
Michael Faraday described this phenomenon as the beautiful flash of light attending the discharge of common electricity. The rapid transition from a non-conducting to a conductive state produces an emission of light. A spark is created when the electric field exceeds the dielectric breakdown strength of the intervening medium. For air, the strength is about 30 kV/cm at sea level. At the beginning stages, free electrons in the gap are accelerated by the electrical field, as they collide with air molecules, they create additional ions and newly freed electrons which are also accelerated. The exponentially-increasing electrons and ions rapidly cause regions of the air in the gap to become conductive in a process called dielectric breakdown. Once the gap breaks down, current flow is limited by the charge or by the impedance of the external power supply. If the power supply continues to supply current, the spark will evolve into a continuous discharge called an electric arc, an electric spark can also occur within insulating liquids or solids, but the breakdown mechanisms are significantly different than for sparks in gases. Lightning is an example of a spark in nature, while electric sparks, large or small, occur in or near many man-made objects. Around 600 BC, Greek philosopher Thales of Miletus observed that amber could be electrified when rubbed with a cloth and attract other objects, in 1671, Leibniz discovered that sparks were associated with electrical phenomena. In 1708, Samuel Wall performed experiments with amber rubbed with cloth to produce sparks, in 1752, Thomas-François Dalibard and Benjamin Franklin independently demonstrated that lightning and electricity were equivalent. In Franklins famous kite experiment, he successfully extracted sparks from a cloud during a thunderstorm, electric sparks are used in spark plugs in gasoline internal combustion engines to ignite fuel and air mixtures. The electric discharge in a spark plug occurs between a central electrode and a grounded terminal on the base of the plug. The voltage for the spark is provided by a coil or magneto that is connected to the spark plug with an insulated wire. Flame igniters use electric sparks to initiate combustion in some furnaces, auto reignition is a safety feature that is used in some flame igniters that senses the electrical conductivity of the flame and uses this information to determine whether a burner flame is lit. This information is used to stop an ignition device from sparking after the flame is lit or restart the flame if it goes out, a spark-gap transmitter uses an electric spark gap to generate radio frequency electromagnetic radiation that can be used as transmitters for wireless communication. Spark gap transmitters were used in the first three decades of radio from 1887–1916. They were later supplanted by vacuum tube systems and by 1940 were no longer used for communication, the wide use of spark-gap transmitters led to the nickname sparks for a ships radio officer
Electric spark
–
Spark plug electric discharge
Electric spark
–
Benjamin Franklin drawing an electric spark to his finger from a key suspended from a kite string.
Electric spark
–
Gas stove burner - the electric spark flame igniter is shown at the left.
Electric spark
–
Spark transmitter used for ship to shore communication up to 10 km (c. 1900)."
11.
Electrostatic attraction
–
Coulombs law, or Coulombs inverse-square law, is a law of physics that describes force interacting between static electrically charged particles. The force of interaction between the charges is attractive if the charges have opposite signs and repulsive if like-signed, the law was first published in 1784 by French physicist Charles Augustin de Coulomb and was essential to the development of the theory of electromagnetism. It is analogous to Isaac Newtons inverse-square law of universal gravitation, Coulombs law can be used to derive Gausss law, and vice versa. The law has been tested extensively, and all observations have upheld the laws principle, ancient cultures around the Mediterranean knew that certain objects, such as rods of amber, could be rubbed with cats fur to attract light objects like feathers. Thales was incorrect in believing the attraction was due to a magnetic effect and he coined the New Latin word electricus to refer to the property of attracting small objects after being rubbed. This association gave rise to the English words electric and electricity, however, he did not generalize or elaborate on this. In 1767, he conjectured that the force between charges varied as the square of the distance. In 1769, Scottish physicist John Robison announced that, according to his measurements, in the early 1770s, the dependence of the force between charged bodies upon both distance and charge had already been discovered, but not published, by Henry Cavendish of England. Finally, in 1785, the French physicist Charles-Augustin de Coulomb published his first three reports of electricity and magnetism where he stated his law and this publication was essential to the development of the theory of electromagnetism. The torsion balance consists of a bar suspended from its middle by a thin fiber, the fiber acts as a very weak torsion spring. In Coulombs experiment, the balance was an insulating rod with a metal-coated ball attached to one end. The ball was charged with a charge of static electricity. The two charged balls repelled one another, twisting the fiber through an angle, which could be read from a scale on the instrument. By knowing how much force it took to twist the fiber through a given angle, the force is along the straight line joining them. If the two charges have the sign, the electrostatic force between them is repulsive, if they have different signs, the force between them is attractive. Coulombs law can also be stated as a mathematical expression. The vector form of the equation calculates the force F1 applied on q1 by q2, if r12 is used instead, then the effect on q2 can be found. It can be calculated using Newtons third law, F2 = −F1
Electrostatic attraction
–
Charles-Augustin de Coulomb
Electrostatic attraction
–
Electromagnetism
12.
Electromagnetism
–
Electromagnetism is a branch of physics involving the study of the electromagnetic force, a type of physical interaction that occurs between electrically charged particles. The electromagnetic force usually exhibits electromagnetic fields such as fields, magnetic fields. The other three fundamental interactions are the interaction, the weak interaction, and gravitation. The word electromagnetism is a form of two Greek terms, ἤλεκτρον, ēlektron, amber, and μαγνῆτις λίθος magnētis lithos, which means magnesian stone. The electromagnetic force plays a role in determining the internal properties of most objects encountered in daily life. Ordinary matter takes its form as a result of forces between individual atoms and molecules in matter, and is a manifestation of the electromagnetic force. Electrons are bound by the force to atomic nuclei, and their orbital shapes. The electromagnetic force governs the processes involved in chemistry, which arise from interactions between the electrons of neighboring atoms, there are numerous mathematical descriptions of the electromagnetic field. In classical electrodynamics, electric fields are described as electric potential, although electromagnetism is considered one of the four fundamental forces, at high energy the weak force and electromagnetic force are unified as a single electroweak force. In the history of the universe, during the epoch the unified force broke into the two separate forces as the universe cooled. Originally, electricity and magnetism were considered to be two separate forces, Magnetic poles attract or repel one another in a manner similar to positive and negative charges and always exist as pairs, every north pole is yoked to a south pole. An electric current inside a wire creates a corresponding magnetic field outside the wire. Its direction depends on the direction of the current in the wire. A current is induced in a loop of wire when it is moved toward or away from a field, or a magnet is moved towards or away from it. While preparing for a lecture on 21 April 1820, Hans Christian Ørsted made a surprising observation. As he was setting up his materials, he noticed a compass needle deflected away from north when the electric current from the battery he was using was switched on. At the time of discovery, Ørsted did not suggest any explanation of the phenomenon. However, three later he began more intensive investigations
Electromagnetism
–
Lightning is an
electrostatic discharge that travels between two charged regions.
Electromagnetism
–
Hans Christian Ørsted.
Electromagnetism
–
André-Marie Ampère
Electromagnetism
–
Michael Faraday
13.
Pith
–
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which store, in eudicots, pith is located in the center of the stem. In monocots, it also into flowering stems and roots. The pith is encircled by a ring of xylem, the xylem, while new pith growth is usually white or pale in color, as the tissue ages it commonly darkens to a deeper brown color. In trees pith is generally present in young growth, but in the trunk, in some plants, the pith in the middle of the stem may dry out and disintegrate, resulting in a hollow stem. A few plants, such as walnuts, have distinctive chambered pith with numerous short cavities, the cells in the peripheral parts of the pith may, in some plants, develop to be different from cells in the rest of the pith. This layer of cells is called the perimedullary region of the pithamus. An example of this can be observed in Hedera helix, a species of ivy, the term pith is also used to refer to the pale, spongy inner layer of the rind - more properly called mesocarp or albedo - of citrus fruits and other hesperidia. The word comes from the Old English word piþa, meaning substance, akin to Middle Dutch pitt, the pith of the sola or other similar plants is used to make the pith helmet. The pith of the palm, although highly toxic to animals in its raw form, is an important human food source in Melanesia and Micronesia by virtue of its starch content. There is an easy, primitive process of extraction from sago pith that leaches away a sufficient amount of the toxins. The form of the starch after processing is similar to tapioca
Pith
–
Elderberry shoot cut longitudinally to show the broad, solid pith (rough-textured, white) inside the wood (smooth, yellow-tinged). Scale in mm.
Pith
–
The tiny centre dark spot (about 1 mm diameter) in this
yew wood is the pith
Pith
–
Walnut shoot cut longitudinally to show the chambered pith found in this genus. Scale in mm.
14.
Georges-Louis Le Sage
–
Georges-Louis Le Sage was a Genevan physicist and is most known for his theory of gravitation, for his invention of an electric telegraph and his anticipation of the kinetic theory of gases. Furthermore, he was a contributor to the Encyclopédie ou Dictionnaire raisonné des sciences, des arts et des métiers, Le Sage was born in Geneva, his father was Georges-Louis Le Sage from Conques in Burgundy and his mother Anne Marie Gamp, a descendant of Théodore Agrippa dAubigné. His father, who was the author of papers on various subjects, occupied his son of his own studies early. Contrary to his father, who allegedly only accepted facts and had little interest in generalization, Le Sage was primarily interested in general, Le Sage took the first regular education at the college of Geneva, were was friendly connected with Jean-André Deluc. Besides philosophy, he studied mathematics under Gabriel Cramer, and physics under Calendrini, later he decided to study medicine in Basel, where he also gave private lessons in mathematics. Here, Le Sage also met Daniel Bernoulli, whose work on the nature of gases was very influential to him. Then Le Sage left Basel and continued to study medicine in Paris, after he came back to Geneva, Le Sage tried to work as a physician, but it was denied because his father was a native from France. There, he was connected with Charles Bonnet. Against the will of his father Le Sage devoted his life to mathematics and, in particular and he tried to become a professor for mathematics in Geneva, but he couldnt get the position. He gave private lessons in mathematics, and his pupils, including La Rochefoucauld, Simon Lhuilier and he was a correspondent of the Paris Academy of Science and also became a Fellow of the Royal Society. Le Sage died at the age of 79 in Geneva, an ardent desire to know the truth,2. An uncommon soundness of understanding,4, a strong desire for precision and distinctness of ideas,5. An excessive weakness of memory,6, a great incapacity of continued attention. Le Sage also suffered from insomnia, and as a result of this he often was unable to work for days, additionally, in 1762 he had an accident which left him nearly blind. To compensate the weakness of his memory, he wrote his thoughts on playing cards - over 35000 cards are still lying in the library of Geneva, as a consequence of his mental disposition, many of his papers remained unfinished and unpublished. For example, his work on Gravitation, a history of theories of gravitation, a treatise on final causes. However, some of them were published by his pupil Pierre Prévost. In 1774 he realised an early electric telegraph, the telegraph had a separate wire for each of the 26 letters of the alphabet and its range was only between two rooms of his home
Georges-Louis Le Sage
–
Georges-Louis Le Sage
15.
Alphabet
–
An alphabet is a standard set of letters that is used to write one or more languages based upon the general principle that the letters represent phonemes of the spoken language. This is in contrast to other types of writing systems, such as syllabaries and logographies, the Proto-Canaanite script, later known as the Phoenician alphabet, is the first fully phonemic script. Thus the Phoenician alphabet is considered to be the first alphabet, the Phoenician alphabet is the ancestor of most modern alphabets, including Arabic, Greek, Latin, Cyrillic, Hebrew, and possibly Brahmic. Under a terminological distinction promoted by Peter T. Daniels, an alphabet is a script that represents both vowels and consonants as letters equally. In this narrow sense of the word the first true alphabet was the Greek alphabet, in other alphabetic scripts such as the original Phoenician, Hebrew or Arabic, letters predominantly or exclusively represent consonants, such a script is also called an abjad. A third type, called abugida or alphasyllabary, is one where vowels are shown by diacritics or modifications of consonantal letters, as in Devanagari. The Khmer alphabet is the longest, with 74 letters, there are dozens of alphabets in use today, the most popular being the Latin alphabet. Many languages use modified forms of the Latin alphabet, with additional letters formed using diacritical marks, while most alphabets have letters composed of lines, there are also exceptions such as the alphabets used in Braille. Alphabets are usually associated with an ordering of letters. This makes them useful for purposes of collation, specifically by allowing words to be sorted in alphabetical order and it also means that their letters can be used as an alternative method of numbering ordered items, in such contexts as numbered lists and number placements. The English word alphabet came into Middle English from the Late Latin word alphabetum, the Greek word was made from the first two letters, alpha and beta. The names for the Greek letters came from the first two letters of the Phoenician alphabet, aleph, which also meant ox, and bet, in the alphabet song in English, the term ABCs is used instead of the word alphabet. Knowing ones ABCs, in general, can be used as a metaphor for knowing the basics about anything, the history of the alphabet started in ancient Egypt. These glyphs were used as guides for logograms, to write grammatical inflections. Based on letter appearances and names, it is believed to be based on Egyptian hieroglyphs and this script had no characters representing vowels, although originally it probably was a syllabary, but unneeded symbols were discarded. An alphabetic cuneiform script with 30 signs including three that indicate the vowel was invented in Ugarit before the 15th century BC. This script was not used after the destruction of Ugarit, the Proto-Sinaitic script eventually developed into the Phoenician alphabet, which is conventionally called Proto-Canaanite before ca.1050 BC. The oldest text in Phoenician script is an inscription on the sarcophagus of King Ahiram and this script is the parent script of all western alphabets
Alphabet
–
Edward Bernard 's "Orbis eruditi", comparing all known alphabets as of 1689.
Alphabet
–
Writing systems
Alphabet
–
A Specimen of
typeset fonts and
languages, by
William Caslon, letter founder; from the 1728
Cyclopaedia.
Alphabet
–
Codex Zographensis in the
Glagolitic alphabet from Medieval
Bulgaria
16.
Alessandro Volta
–
He invented the Voltaic pile in 1799, and reported the results of his experiments in 1800 in a two-part letter to the President of the Royal Society. With this invention Volta proved that electricity could be generated chemically, Voltas invention sparked a great amount of scientific excitement and led others to conduct similar experiments which eventually led to the development of the field of electrochemistry. Alessandro Volta also drew admiration from Napoleon Bonaparte for his invention, Volta enjoyed a certain amount of closeness with the Emperor throughout his life and he was conferred numerous honours by him. Alessandro Volta held the chair of physics at the University of Pavia for nearly 40 years and was widely idolised by his students. Despite his professional success, Volta tended to be a person inclined towards domestic life, at this time he tended to live secluded from public life and more for the sake of his family until his eventual death in 1827 from a series of illnesses which began in 1823. The SI unit of electric potential is named in his honour as the volt, Volta was born in Como, a town in present-day northern Italy, on 18 February 1745. In 1794, Volta married a lady also from Como, Teresa Peregrini. His father, Filippo Volta, was of noble lineage and his mother, Donna Maddalena, came from the family of the Inzaghis. In 1774, he became a professor of physics at the Royal School in Como, a year later, he improved and popularised the electrophorus, a device that produced static electricity. In 1777, he travelled through Switzerland, there he befriended H. B. de Saussure. In the years between 1776 and 1778, Volta studied the chemistry of gases and he researched and discovered methane after reading a paper by Benjamin Franklin of the United States on flammable air. In November 1776, he found methane at Lake Maggiore, and he devised experiments such as the ignition of methane by an electric spark in a closed vessel. Volta also studied what we now call electrical capacitance, developing separate means to both electrical potential and charge, and discovering that for a given object, they are proportional. This is called Voltas Law of Capacitance, and it was for work the unit of electrical potential has been named the volt. In 1779 he became a professor of physics at the University of Pavia. Luigi Galvani, an Italian physicist, discovered something he named animal electricity when two different metals were connected in series with a leg and to one another. Volta realised that the frogs leg served as both a conductor of electricity and as a detector of electricity and he replaced the frogs leg with brine-soaked paper, and detected the flow of electricity by other means familiar to him from his previous studies. This may be called Voltas Law of the electrochemical series, Volta had determined that the most effective pair of dissimilar metals to produce electricity was zinc and copper
Alessandro Volta
–
Alessandro Giuseppe Antonio Anastasio Volta
Alessandro Volta
–
Luigi Galvani, Volta's rival.
Alessandro Volta
–
Volta explains the principle of the "electric column" to
Napoleon in 1801.
17.
Voltaic pile
–
The voltaic pile was the first electrical battery that could continuously provide an electric current to a circuit. It was invented by Alessandro Volta, who published his experiments in 1799, the entire 19th century electrical industry was powered by batteries related to Voltas until the advent of the dynamo in the 1870s. Voltas invention built on Luigi Galvanis 1780s discovery of how a circuit of two metals and a leg can cause the frogs leg to respond. Volta demonstrated in 1794 that when two metals and brine-soaked cloth or cardboard are arranged in a circuit they produce an electric current, in 1800, Volta stacked several pairs of alternating copper and zinc discs separated by cloth or cardboard soaked in brine to increase the electrolyte conductivity. When the top and bottom contacts were connected by a wire, an electric current flowed through the voltaic pile, on 20 March 1800, Volta wrote to the London Royal Society to describe the technique for producing electric current using his device. On learning of the pile, William Nicholson and Anthony Carlisle used it to discover the electrolysis of water. He also used the voltaic pile to decompose chemicals and to produce new chemicals, William Hyde Wollaston showed that electricity from voltaic piles had identical effects to those of electricity produced by friction. In 1802 Vasily Petrov used voltaic piles in the discovery and research of electric arc effects, sir Humphry Davy and Andrew Crosse were among the first to develop large voltaic piles. Davy used a 2000-pair pile made for the Royal Institution in 1808 to demonstrate carbon arc discharge and isolate five new elements, barium, calcium, boron, strontium and magnesium. Because Volta believed that the electromotive force occurred at the contact between the two metals, Voltas piles had a different design than the modern design illustrated on this page. His piles had one extra disc of copper at the top, in contact with the zinc, expanding on Volta’s work and the electro-magnetism work of his mentor Humphry Davy, Michael Faraday utilized both magnets and the voltaic pile in his experiments with electricity. Faraday believed that all “electricities” being studied at the time were one and his work to prove this theory led him to propose two laws of electrochemistry which stood in direct conflict with the current scientific beliefs of the day as laid down by Volta thirty years earlier. Because of their contributions to the understanding of field of study, Faraday. The words electrode and electrolyte, used above to describe Voltas work, are due to Faraday, indeed, Volta himself experimented with a pile whose cardboard discs had dried out, most likely accidentally. The first to publish was Johann Wilhelm Ritter in 1802, albeit in an obscure journal, one form of dry pile is the Zamboni pile. The dry pile could be referred to as the ancestor of the dry cell. The strength of the pile is expressed in terms of its force, or emf. Alessandro Voltas theory of contact tension considered that the emf, which drives the current through a circuit containing a voltaic cell
Voltaic pile
–
A voltaic pile on display in the
Tempio Voltiano (the Volta Temple) near Volta's home in
Como.
Voltaic pile
–
Schematic diagram of a
copper –
zinc voltaic pile. The copper and zinc discs were separated by cardboard or felt spacers soaked in salt water (the electrolyte). Volta's original piles contained an additional zinc disk at the bottom, and an additional copper disk at the top. These were later shown to be unnecessary.
18.
Continuous current
–
Direct current is a flow of electrical charge carriers that always takes place in the same direction. The current need not always have the magnitude, but if it is to be defined as dc. This contrasts with alternating current which varies the direction of flow, sources of direct current include power supplies, electrochemical cells and batteries, and photovoltaic cells and panels. The intensity, or amplitude, of a direct current might fluctuate with time, in some such cases the dc has an ac component superimposed on it. An example of this is the output of a cell that receives a modulated light communications signal. A source of dc is sometimes called a dc generator, batteries and various other sources of dc produce a constant voltage. This is called pure dc and can be represented by a straight, the peak and effective values are the same. The peak to peak value is zero because the instantaneous amplitude never changes, in some instances the value of a dc voltage pulsates or oscillates rapidly with time, in a manner similar to the changes in an ac wave. The unfiltered output of a wave or a full wave rectifier. In 1820, Hans Christian Orsted discovered that electrical current creates a magnetic field and this discovery made scientists relate magnetism to the electric phenomena. In 1879, Thomas Edison invented the light bulb. He improved a 50-year-old idea using lower current electricity, a vacuum inside the globe and a small carbonized filament. At that time, the idea of lightning was not new. Edison not only invented an incandescent electric light, but an electric lighting system contained all the necessary elements to make the incandescent light safe, economical. Prior to 1879, direct current electricity had been used in lighting for the outdoors and it was in the 1880s when the modern electric utility industry began. It was an evolution from street lighting systems and from gas and it was located in Lower Manhattan, on Pearl Street. This station provided light and electricity to customers in a one square mile range, the station was called Thomas Edisons Pearl Street Electricity Generating Station. This station introduced four elements of an electric utility system, Efficient distribution, competitive price, reliable central generation
Continuous current
–
Direct Current (red curve). The horizontal axis measures time; the vertical, current or voltage.
19.
Electricity
–
Electricity is the set of physical phenomena associated with the presence of electric charge. Although initially considered a separate to magnetism, since the development of Maxwells Equations both are recognized as part of a single phenomenon, electromagnetism. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges, in addition, electricity is at the heart of many modern technologies. The presence of a charge, which can be either positive or negative. On the other hand, the movement of charges, which is known as electric current. When a charge is placed in a location with non-zero electric field, the magnitude of this force is given by Coulombs Law. Thus, if that charge were to move, the field would be doing work on the electric charge. Electrical phenomena have been studied since antiquity, though progress in theoretical understanding remained slow until the seventeenth and eighteenth centuries. Even then, practical applications for electricity were few, and it would not be until the nineteenth century that engineers were able to put it to industrial and residential use. The rapid expansion in electrical technology at this time transformed industry, electricitys extraordinary versatility means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. Electrical power is now the backbone of modern industrial society, long before any knowledge of electricity existed, people were aware of shocks from electric fish. Ancient Egyptian texts dating from 2750 BCE referred to these fish as the Thunderer of the Nile, Electric fish were again reported millennia later by ancient Greek, Roman and Arabic naturalists and physicians. Patients suffering from such as gout or headache were directed to touch electric fish in the hope that the powerful jolt might cure them. Ancient cultures around the Mediterranean knew that certain objects, such as rods of amber, Thales was incorrect in believing the attraction was due to a magnetic effect, but later science would prove a link between magnetism and electricity. He coined the New Latin word electricus to refer to the property of attracting small objects after being rubbed and this association gave rise to the English words electric and electricity, which made their first appearance in print in Thomas Brownes Pseudodoxia Epidemica of 1646. Further work was conducted by Otto von Guericke, Robert Boyle, Stephen Gray, in the 18th century, Benjamin Franklin conducted extensive research in electricity, selling his possessions to fund his work. In June 1752 he is reputed to have attached a key to the bottom of a dampened kite string. A succession of jumping from the key to the back of his hand showed that lightning was indeed electrical in nature
Electricity
–
Lightning is one of the most dramatic effects of electricity.
Electricity
–
Thales, the earliest known researcher into electricity
Electricity
–
Benjamin Franklin conducted extensive research on electricity in the 18th century, as documented by
Joseph Priestley (1767) History and Present Status of Electricity, with whom Franklin carried on extended correspondence.
Electricity
–
Michael Faraday 's discoveries formed the foundation of electric motor technology
20.
Electrostatic generator
–
An electrostatic generator, or electrostatic machine, is an electromechanical generator that produces static electricity, or electricity at high voltage and low continuous current. Electrostatic generators operate by using manual power to mechanical work into electric energy. The charge is generated by one of two methods, either the effect or electrostatic induction. Electrostatic machines are used in science classrooms to safely demonstrate electrical forces. Electrostatic generators such as the Van de Graaff generator, and variations as the Pelletron, a primitive form of frictional machine was invented around 1663 by Otto von Guericke, using a sulphur globe that could be rotated and rubbed by hand. It may not actually have been rotated during use and was not intended to produce electricity, isaac Newton suggested the use of a glass globe instead of a sulphur one. Francis Hauksbee improved the design, with his frictional electrical machine that enabled a glass sphere to be rotated rapidly against a woollen cloth. Generators were further advanced when Prof. Georg Matthias Bose of Wittenberg added a collecting conductor. Bose was the first to employ the prime conductor in such machines, in 1746, William Watsons machine had a large wheel turning several glass globes, with a sword and a gun barrel suspended from silk cords for its prime conductors. Johann Heinrich Winckler, professor of physics at Leipzig, substituted a leather cushion for the hand, during 1746, Jan Ingenhousz invented electric machines made of plate glass. In 1768, Jesse Ramsden constructed a widely used version of an electrical generator. In 1783, Dutch scientist Martin van Marum of Haarlem designed a large electrostatic machine of high quality with glass disks 1.65 meters in diameter for his experiments. Capable of producing voltage with either polarity, it was built under his supervision by John Cuthbertson of Amsterdam the following year, the generator is currently on display at the Teylers Museum in Haarlem. In 1785, N. Rouland constructed a machine that rubbed two grounded tubes covered with hare fur. The Winter machine possessed higher efficiency than earlier friction machines, in the 1830s, Georg Ohm possessed a machine similar to the Van Marum machine for his research. In 1840, the Woodward machine was developed by improving the Ramsden machine, also in 1840, the Armstrong hydroelectric machine was developed, using steam as a charge carrier. The presence of charge imbalance means that the objects will exhibit attractive or repulsive forces. Rubbing two non-conductive objects generates a great amount of static electricity and this is not the result of friction, two non-conductive surfaces can become charged by just being placed one on top of the other
Electrostatic generator
–
A
Van de Graaff generator, for class room demonstrations
Electrostatic generator
–
Martinus van Marum's
Electrostatic generator at
Teylers Museum
Electrostatic generator
–
Typical friction machine using a glass globe, common in the 18th century
Electrostatic generator
–
Holtz's influence machine
21.
Leyden jar
–
A Leyden jar, or Leiden jar, is a device that stores static electricity between two electrodes on the inside and outside of a glass jar. It was the form of a capacitor. It was invented independently by German cleric Ewald Georg von Kleist on 11 October 1745, the invention was named after the city. The Leyden jar was used to conduct many experiments in electricity. The Leyden jar was the first means of storing an electric charge which then could be discharged at the experimenters will, Leyden jars are still used in education to demonstrate the principles of electrostatics. The Ancient Greeks already knew that pieces of amber could attract lightweight particles after being rubbed, the amber becomes electrified by triboelectric effect, mechanical separation of charge in a dielectric. The Greek word for amber is ηλεκτρον and is the origin of the word electricity, around 1650, Otto von Guericke built a crude electrostatic generator, a sulphur ball that rotated on a shaft. When Guericke held his hand against the ball and turned the shaft quickly and this experiment inspired the development of several forms of friction machines, that greatly helped in the study of electricity. Despite its mundane and safe appearance, the Leyden jar is a high voltage device, the ball on the tip of the rod is a corona ball to prevent leakage of the energy into the air by point discharge. He was the deacon at the cathedral of Camin in Pomerania, in 1744 von Kleist tried to accumulate electricity in a small medicine bottle filled with alcohol with a nail inserted in the cork. He was following up on an experiment developed by Georg Matthias Bose where electricity had been sent though water to set alcoholic spirits alight and he attempted to charge the bottle from a large prime conductor suspended above his friction machine. Kleist was convinced that an electric charge could be collected. He received a significant shock from the device when he touched the nail through the cork while still cradling the bottle in his other hand. It took some time before Kleists student associates at Leyden worked out that the hand provided an essential element, Andreas Cuneaus, appears to have been the first to receive communications from von Kleist about the storage capacity of the jar. He attempted to duplicate the experiment using a glass of beer, Cunaeus and Musschenbroek also received severe shocks, and Musschenbroek communicated the experiment to Abbé Nollet, René Antoine Ferchault de Réaumur, and the wider French scientific community. Musschenbroeks outlet in France for the sale of his companys cabinet devices was the Abbé Nollet, Nollet then gave the electrical storage device the name Leyden Jar and promoted it as a special type of flask to his market of wealthy men with scientific curiosity. The Kleistian jar was therefore promoted as the Leyden Jar as having been discovered by Pieter van Musschenbroek, daniel Gralath was the first to connect several jars in parallel to increase the total possible stored charge. The term battery was coined by Benjamin Franklin for these combinations, the term was later used for combinations of multiple electrochemical cells, the modern meaning of the term battery
Leyden jar
–
A
battery of four water-filled Leyden jars,
Museum Boerhaave, Leiden
Leyden jar
–
Early water-filled Leyden jar
22.
Germans
–
Germans are a Germanic ethnic group native to Central Europe, who share a common German ancestry, culture and history. German is the mother tongue of a substantial majority of ethnic Germans. The English term Germans has historically referred to the German-speaking population of the Holy Roman Empire since the Late Middle Ages, before the collapse of communism and the reunification of Germany in 1990, Germans constituted the largest divided nation in Europe by far. Ever since the outbreak of the Protestant Reformation within the Holy Roman Empire, of approximately 100 million native speakers of German in the world, roughly 80 million consider themselves Germans. Thus, the number of Germans lies somewhere between 100 and more than 150 million, depending on the criteria applied. Today, people from countries with German-speaking majorities most often subscribe to their own national identities, the German term Deutsche originates from the Old High German word diutisc, referring to the Germanic language of the people. It is not clear how commonly, if at all, the word was used as an ethnonym in Old High German, used as a noun, ein diutscher in the sense of a German emerges in Middle High German, attested from the second half of the 12th century. The Old French term alemans is taken from the name of the Alamanni and it was loaned into Middle English as almains in the early 14th century. The word Dutch is attested in English from the 14th century, denoting continental West Germanic dialects, while in most Romance languages the Germans have been named from the Alamanni, the Old Norse, Finnish and Estonian names for the Germans were taken from that of the Saxons. In Slavic languages, the Germans were given the name of němьci, originally with a meaning foreigner, the English term Germans is only attested from the mid-16th century, based on the classical Latin term Germani used by Julius Caesar and later Tacitus. It gradually replaced Dutch and Almains, the latter becoming mostly obsolete by the early 18th century, the Germans are a Germanic people, who as an ethnicity emerged during the Middle Ages. Originally part of the Holy Roman Empire, around 300 independent German states emerged during its decline after the Peace of Westphalia in 1648 ending the Thirty Years War and these states eventually formed into modern Germany in the 19th century. The concept of a German ethnicity is linked to Germanic tribes of antiquity in central Europe, the early Germans originated on the North German Plain as well as southern Scandinavia. By the 2nd century BC, the number of Germans was significantly increasing and they began expanding into eastern Europe, during antiquity these Germanic tribes remained separate from each other and did not have writing systems at that time. In the European Iron Age the area that is now Germany was divided into the La Tène horizon in Southern Germany and the Jastorf culture in Northern Germany. By 55 BC, the Germans had reached the Danube river and had either assimilated or otherwise driven out the Celts who had lived there, and had spread west into what is now Belgium and France. Conflict between the Germanic tribes and the forces of Rome under Julius Caesar forced major Germanic tribes to retreat to the east bank of the Rhine, in Roman-held territories with Germanic populations, the Germanic and Roman peoples intermarried, and Roman, Germanic, and Christian traditions intermingled. The adoption of Christianity would later become an influence in the development of a common German identity
Germans
Germans
–
Germanic Kingdoms in Europe c. 500 AD
Germans
–
Extent of
Holy Roman Empire in 972 (red line) and 1035 (red dots) with
Kingdom of Germany marked in blue
Germans
–
18 January 1871: The proclamation of the
German Empire in the
Hall of Mirrors of the
Palace of Versailles.
Bismarck appears in white. The Grand Duke of Baden stands beside Wilhelm, leading the cheers. Crown Prince Friedrich, later
Friedrich III, stands on his father's right.
23.
Polymath
–
A polymath is a person whose expertise spans a significant number of different subject areas, such a person is known to draw on complex bodies of knowledge to solve specific problems. The term was first used in the 17th century, the related term, the term is often used to describe great thinkers of the Renaissance and the Enlightenment who excelled at several fields in science and the arts. In the Italian Renaissance, the idea of the polymath was expressed by Leon Battista Alberti and this term entered the lexicon during the twentieth century and has now been applied to great thinkers living before and after the Renaissance. Renaissance man was first recorded in written English in the early 20th century and it is now used to refer to great thinkers living before, during, or after the Renaissance. Leonardo da Vinci has often described as the archetype of the Renaissance man. These polymaths had an approach to education that reflected the ideals of the humanists of the time. A gentleman or courtier of that era was expected to speak several languages, play an instrument, write poetry. The idea of an education was essential to achieving polymath ability. At this time, universities did not specialize in specific areas but rather trained students in an array of science, philosophy. This universal education gave them a grounding from which they could continue into apprenticeship toward becoming a master of a specific field, aside from Renaissance man as mentioned above, similar terms in use are Homo Universalis and Uomo Universale, which translate to universal person or universal man. The related term generalist—contrasted with a used to describe a person with a general approach to knowledge. The term Universal Genius or Versatile Genius is also used, with Leonardo da Vinci as the prime example again. The term seems to be used especially when a person has made lasting contributions in at least one of the fields in which he was involved. When a person is described as having knowledge, they exhibit a vast scope of knowledge. This designation may be anachronistic, however, in the case of such as Eratosthenes whose reputation for having encyclopedic knowledge predates the existence of any encyclopedic object. One whose accomplishments are limited to athletics would not be considered a polymath in the sense of the word. An example is Howard Baker, who was called a sporting polymath by the Encyclopedia of British Football for winning high jump titles and playing cricket, football, many polymaths from across the centuries have their roots in medical applications. One of the well known polymaths, Leonardo da Vinci, was known for his immense interest in human anatomical structure
Polymath
–
Leonardo da Vinci, a polymath of the
Renaissance era.
Polymath
–
Abū Rayḥān al-Bīrūnī was a notable Persian polymath.
Polymath
–
Galileo was one of the most influential polymaths.
Polymath
–
Medieval German polymath
Hildegard of Bingen, shown dictating to her scribe in an illumination from
Liber Scivias
24.
Galvanometer
–
A galvanometer is an electromechanical instrument for detecting and measuring electric current. The most common use of galvanometers was as analog measuring instruments, called ammeters, a galvanometer works as an actuator, by producing a rotary deflection, in response to electric current flowing through a coil in a constant magnetic field. Galvanometers developed from the observation that the needle of a compass is deflected near a wire that has electric current flowing through it. They were the first instruments used to detect and measure small amounts of electric currents, the name comes from the Italian electricity researcher Luigi Galvani, who in 1791 discovered the principle of the frog galvanoscope – that electric current would make the legs of a dead frog jerk. Sensitive galvanometers have been essential for the development of science and technology in many fields, today the main type of galvanometer mechanism, still in use, is the moving coil, DArsonval/Weston type. Modern galvanometers, of the DArsonval/Weston type, are constructed with a small pivoting coil of wire in the field of a permanent magnet, the coil is attached to a thin pointer that traverses a calibrated scale. A tiny torsion spring pulls the coil and pointer to the zero position, when a direct current flows through the coil, the coil generates a magnetic field. This field acts against the permanent magnet, the coil twists, pushing against the spring, and moves the pointer. The hand points at a scale indicating the electric current, careful design of the pole pieces ensures that the magnetic field is uniform, so that the angular deflection of the pointer is proportional to the current. A useful meter generally contains provision for damping the mechanical resonance of the coil and pointer. The basic sensitivity of a meter might be, for instance,100 microamperes full scale, such meters are often calibrated to read some other quantity that can be converted to a current of that magnitude. The use of current dividers, often called shunts, allows a meter to be calibrated to measure larger currents, a meter can be calibrated as a DC voltmeter if the resistance of the coil is known by calculating the voltage required to generate a full scale current. A meter can be configured to read other voltages by putting it in a voltage divider circuit and this is generally done by placing a resistor in series with the meter coil. A meter can be used to resistance by placing it in series with a known voltage. In a preparatory step, the circuit is completed and the resistor adjusted to produce full scale deflection. When an unknown resistor is placed in series in the circuit the current will be less than full scale and an appropriately calibrated scale can display the value of the previously unknown resistor. Because the pointer of the meter is usually a distance above the scale of the meter. To counter this, some include a mirror along the markings of the principal scale
Galvanometer
–
D'Arsonval/Weston galvanometer movement (ca. 1900). Part of the magnet's left
pole piece is broken out to show the coil.
Galvanometer
–
An early D'Arsonval galvanometer showing magnet and rotating coil
Galvanometer
–
Tangent galvanometer made by J. H. Bunnell Co. around 1890.
Galvanometer
–
Top view of a tangent galvanometer made about 1950. The indicator needle of the compass is perpendicular to the shorter, black magnetic needle.
25.
Peter Barlow (mathematician)
–
Peter Barlow was an English mathematician and physicist. In 1801, Barlow was appointed assistant mathematics master at the Royal Military Academy, Woolwich, the latter became known as Barlows Tables and gives squares, cubes, square roots, cube roots, and reciprocals of all integer numbers from 1 to 10,000. These tables were regularly reprinted until 1965, when computers rendered them obsolete and he contributed to Reess Cyclopædia articles on Algebra, Analysis, Geometry and Strength of Materials. Barlow also contributed largely to the Encyclopædia Metropolitana, in collaboration with optician George Dollond, Barlow built an achromatic lens that utilized liquid carbon disulfide. In 1833, Barlow built an achromatic lens of joined flint glass. A derivative of this design, named a Barlow lens, is used in modern astronomy. In 1823, he was made a fellow of the Royal Society, two years later, he received its Copley Medal for his work on correcting the deviation in ship compasses caused by the presence of iron in the hull. Some of his research was done in collaboration with Samuel Hunter Christie. He is credited with the eponymous Barlows wheel and with Barlows law, steam locomotion received much attention at Barlows hands and he sat on the railway commissions of 1836,1839,1842 and 1845. He also conducted investigations for the newly formed Railway Inspectorate in the early 1840s. Barlow made several contributions to the theory of strength of materials, including Essay on the strength, the sixth edition of this work was prepared by Barlows two sons after his death and contains a biography of their father. Barlow also applied his knowledge of materials to the design of bridges and his sons Peter W. Barlow and William Henry Barlow became notable civil engineers of the 19th century. He was elected a Foreign Honorary Member of the American Academy of Arts, following his death in 1862, he was buried in Charlton Cemetery. 2147483647, Barlow commented on this Mersenne prime Barlows Formula Calculator Biographical information
Peter Barlow (mathematician)
–
Peter Barlow
Peter Barlow (mathematician)
–
Peter Barlow FRS – gravestone in Charlton Cemetery, London SE7
26.
William Sturgeon
–
William Sturgeon was an English physicist and inventor who made the first electromagnets, and invented the first practical English electric motor. Sturgeon was born in Whittington, near Carnforth, Lancashire, and he joined the army in 1802 and taught himself mathematics and physics. In 1824 he became Lecturer in Science and Philosophy at the East India Companys Military Seminary at Addiscombe, Surrey and he displayed its power by lifting nine pounds with a seven-ounce piece of iron wrapped with wire through which a current from a single battery was sent. In 1832 he was appointed to the staff of the Adelaide Gallery of Practical Science in London. In 1836 Sturgeon established the journal Annals of Electricity, Magnetism and Chemistry, Sturgeon was a close associate of John Peter Gassiot and Charles Vincent Walker and the three were instrumental in founding the London Electrical Society in 1837. In 1840 he became superintendent of the Royal Victoria Gallery of Practical Science in Manchester, the Gallery closed in 1842, and he earned a living by lecturing and demonstrating. He died in Prestwich in 1850, and is buried in the Churchyard of St Marys Parish Church in a tomb that calls him William Sturgeon ~ The Electrician. Frank A. J. L. James, Oxford Dictionary of National Biography, Oxford University Press, accessed 25 July 2007 Kargon, Science in Victorian Manchester, Enterprise and Expertise. Vibart, H. M. Addiscombe, its heroes and men of note
William Sturgeon
–
William Sturgeon
27.
Electromagnet
–
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field disappears when the current is turned off, electromagnets usually consist of insulated wire wound into a coil. A current through the wire creates a field which is concentrated in the hole in the center of the coil. The main advantage of an electromagnet over a permanent magnet is that the field can be quickly changed by controlling the amount of electric current in the winding. However, unlike a permanent magnet that needs no power, an electromagnet requires a supply of current to maintain the magnetic field. Electromagnets are also employed in industry for picking up and moving heavy objects such as scrap iron. Danish scientist Hans Christian Ørsted discovered in 1820 that electric currents create magnetic fields, british scientist William Sturgeon invented the electromagnet in 1824. His first electromagnet was a piece of iron that was wrapped with about 18 turns of bare copper wire. The iron was varnished to insulate it from the windings, when a current was passed through the coil, the iron became magnetized and attracted other pieces of iron, when the current was stopped, it lost magnetization. Sturgeon displayed its power by showing that although it only weighed seven ounces, however, Sturgeons magnets were weak because the uninsulated wire he used could only be wrapped in a single spaced out layer around the core, limiting the number of turns. Beginning in 1830, US scientist Joseph Henry systematically improved and popularized the electromagnet, the first major use for electromagnets was in telegraph sounders. A portative electromagnet is one designed to just hold material in place, a tractive electromagnet applies a force and moves something. The solenoid is a coil of wire, and the plunger is made of a such as soft iron. Applying a current to the solenoid applies a force to the plunger, the plunger stops moving when the forces upon it are balanced. For example, the forces are balanced when the plunger is centered in the solenoid, the maximum uniform pull happens when one end of the plunger is at the middle of the solenoid. For units using inches, pounds force, and amperes with long, slender, solenoids, for example, a 12-inch long coil with a long plunger of 1-square inch cross section and 11,200 ampere-turns had a maximum pull of 8.75 pounds. The maximum pull is increased when a stop is inserted into the solenoid. The stop becomes a magnet that will attract the plunger, it adds little to the pull when the plunger is far away
Electromagnet
–
Industrial electromagnet lifting scrap iron, 1914
Electromagnet
–
A simple electromagnet consisting of a coil of insulated wire wrapped around an iron core. A core of ferromagnetic material like iron serves to increase the magnetic field created. The strength of magnetic field generated is proportional to the amount of current through the winding.
Electromagnet
–
Laboratory electromagnet. Produces 2 T field with 20 A current.
Electromagnet
–
Magnet in a
mass spectrometer
28.
Iron
–
Iron is a chemical element with symbol Fe and atomic number 26. It is a metal in the first transition series and it is by mass the most common element on Earth, forming much of Earths outer and inner core. It is the fourth most common element in the Earths crust, like the other group 8 elements, ruthenium and osmium, iron exists in a wide range of oxidation states, −2 to +6, although +2 and +3 are the most common. Elemental iron occurs in meteoroids and other low oxygen environments, but is reactive to oxygen, fresh iron surfaces appear lustrous silvery-gray, but oxidize in normal air to give hydrated iron oxides, commonly known as rust. Unlike the metals that form passivating oxide layers, iron oxides occupy more volume than the metal and thus flake off, Iron metal has been used since ancient times, although copper alloys, which have lower melting temperatures, were used even earlier in human history. Pure iron is soft, but is unobtainable by smelting because it is significantly hardened and strengthened by impurities, in particular carbon. A certain proportion of carbon steel, which may be up to 1000 times harder than pure iron. Crude iron metal is produced in blast furnaces, where ore is reduced by coke to pig iron, further refinement with oxygen reduces the carbon content to the correct proportion to make steel. Steels and iron alloys formed with metals are by far the most common industrial metals because they have a great range of desirable properties. Iron chemical compounds have many uses, Iron oxide mixed with aluminium powder can be ignited to create a thermite reaction, used in welding and purifying ores. Iron forms binary compounds with the halogens and the chalcogens, among its organometallic compounds is ferrocene, the first sandwich compound discovered. Iron plays an important role in biology, forming complexes with oxygen in hemoglobin and myoglobin. Iron is also the metal at the site of many important redox enzymes dealing with cellular respiration and oxidation and reduction in plants. A human male of average height has about 4 grams of iron in his body and this iron is distributed throughout the body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, ferritin, hemosiderin, and transport in plasma. The mechanical properties of iron and its alloys can be evaluated using a variety of tests, including the Brinell test, Rockwell test, the data on iron is so consistent that it is often used to calibrate measurements or to compare tests. An increase in the content will cause a significant increase in the hardness. Maximum hardness of 65 Rc is achieved with a 0. 6% carbon content, because of the softness of iron, it is much easier to work with than its heavier congeners ruthenium and osmium. Because of its significance for planetary cores, the properties of iron at high pressures and temperatures have also been studied extensively
Iron
–
Iron, 26 Fe
Iron
–
Spectral lines of iron
Iron
–
Iron meteorites, similar in composition to the Earth's inner- and outer core
Iron
–
Hydrated
iron(III) chloride, also known as ferric chloride
29.
Joseph Henry
–
Joseph Henry was an American scientist who served as the first Secretary of the Smithsonian Institution. He was the secretary for the National Institute for the Promotion of Science and he was highly regarded during his lifetime. While building electromagnets, Henry discovered the phenomenon of self-inductance. He also discovered mutual inductance independently of Michael Faraday, though Faraday was the first to make the discovery, Henry developed the electromagnet into a practical device. He invented a precursor to the doorbell and electric relay. The SI unit of inductance, the henry, is named in his honor, Henrys work on the electromagnetic relay was the basis of the practical electrical telegraph, invented by Samuel F. B. Morse and Sir Charles Wheatstone, separately. Henry was born in Albany, New York, to Scottish immigrants Ann Alexander Henry and his parents were poor, and Henrys father died while he was still young. For the rest of his childhood, Henry lived with his grandmother in Galway and he attended a school which would later be named the Joseph Henry Elementary School in his honor. After school, he worked at a store, and at the age of thirteen became an apprentice watchmaker. Josephs first love was theater and he came close to becoming a professional actor and his interest in science was sparked at the age of sixteen by a book of lectures on scientific topics titled Popular Lectures on Experimental Philosophy. In 1819 he entered The Albany Academy, where he was free tuition. Even with free tuition he was so poor that he had to himself with teaching. He intended to go into medicine, but in 1824 he was appointed an assistant engineer for the survey of the State road being constructed between the Hudson River and Lake Erie, from then on, he was inspired to a career in either civil or mechanical engineering. Henry excelled at his studies and in 1826 was appointed Professor of Mathematics, some of his most important research was conducted in this new position. His curiosity about terrestrial magnetism led him to experiment with magnetism in general, using this technique, he built the strongest electromagnet at the time for Yale. The latter made the telegraph feasible, because of his early experiments in electromagnetism some historians credit Henry with discoveries pre-dating Faraday and Hertz, however, Henry is not credited due to not publishing his work. Using his newly developed electromagnetic principle, Henry in 1831 created one of the first machines to use electromagnetism for motion and this was the earliest ancestor of modern DC motor. It did not make use of rotating motion, but was merely an electromagnet perched on a pole, rocking back and this apparatus allowed Henry to recognize the property of self inductance
Joseph Henry
–
Joseph Henry
Joseph Henry
–
Historical marker in Academy Park (Albany, New York) commemorating Henry's work with electricity.
Joseph Henry
–
Joseph Henry, taken between 1865 and 1878, possibly by Mathew Brady.
Joseph Henry
–
Henry's grave,
Oak Hill Cemetery, Washington, D.C.
30.
The Albany Academy
–
The Albany Academy is an independent college preparatory day school for boys in Albany, New York, USA, enrolling students from Preschool to Grade 12. It was established in 1813 by a signed by Mayor Philip Schuyler Van Rensselaer. In July 2007, the teams of The Albany Academy. Both schools retain much of their tradition and character and each continues to give diplomas under its own name. Tuition ranges from $13,000 for Preschool, up to $22,500 for grade 12, the Albany Academy is the oldest boys day school in the New York Capital Region, chartered in March 1813 to educate the sons of Albanys political elite and rapidly growing merchant class. In the Census three years prior, Albany was the tenth-largest city in the United States, and would remain so through the 1850s due to the prominence of the Erie Canal. Classes began within months after the charter was granted, offering a college preparatory track, two years later, in 1815, a purpose-built building was completed in present-day Academy Park, adjacent to the New York State Capitol. The Federal-style building, now known as the Old Academy and headquarters of the City School District of Albany, was designed by renowned Albany architect Philip Hooker. The building is listed on the National Register of Historic Places for its architectural significance, in 2005 the school ended compulsory involvement in the program in favor of a House-based leadership program commonly found in English preparatory schools. Designed by Marcus T. Reynolds in the style, the building incorporates many elements of the Old Academy building, namely the main entryway. The red-brick Academy buildings marble cornerstone was laid by the then Governor, all grades enrolled in The Albany Academy are housed under the same roof, a point of pride for the Academy Community. In 2005, The Albany Academy ended its long standing Army JROTC program and this decision came due to declining enrollment among other factors. Certain military aspects are still available to students, but are all electives, the Board of Trustees announced that The Albany Academy and Albany Academy for Girls would merge into The Albany Academies in July 2007. Other on-campus facilities include Leonard House, the Head of Schools residence, drawn predominately from a six-county area and from within a radius of 65 miles, the student body is ethnically, religiously, and economically diverse. The total 2005–06 school population is 340 boys, including 82 in the Lower School,71 in the Middle School, there is a total of six countries represented in the school. Students are encouraged to participate in all aspects of school life, they are expected to conduct themselves responsibly and treat each other. Students are responsible for upholding school rules, the Albany Academy adheres to a school-wide honor code. Student Council members, especially seniors, occupy important leadership positions at Albany Academy, the schools core values include responsibility, self-discipline, compassion, ingenuity, respect, service, integrity and perseverance
The Albany Academy
–
Honor Integritas Officium
The Albany Academy
–
Old Academy Building, now the
Joseph Henry Memorial
The Albany Academy
–
The Academy's cupola rises above the main building and is topped with a fish and pumpkin.
The Albany Academy
–
Learned Hand, Class of 1889
31.
Relay
–
A relay is an electrically operated switch. Many relays use an electromagnet to operate a switch, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a separate low-power signal, the first relays were used in long distance telegraph circuits as amplifiers, they repeated the signal coming in from one circuit and re-transmitted it on another circuit. Relays were used extensively in telephone exchanges and early computers to perform logical operations, a type of relay that can handle the high power required to directly control an electric motor or other loads is called a contactor. Solid-state relays control power circuits with no moving parts, instead using a device to perform switching. Magnetic latching relays require one pulse of power to move their contacts in one direction. Repeated pulses from the same input have no effect, magnetic latching relays are useful in applications where interrupted power should not be able to transition the contacts. Magnetic latching relays can have single or dual coils. On a single device, the relay will operate in one direction when power is applied with one polarity. On a dual coil device, when polarized voltage is applied to the coil the contacts will transition. AC controlled magnetic latch relays have single coils that employ steering diodes to differentiate between operate and reset commands, american scientist Joseph Henry is often claimed to have invented a relay in 1835 in order to improve his version of the electrical telegraph, developed earlier in 1831. However, there is little in the way of documentation to suggest he had made the discovery prior to 1837. It is claimed that English inventor Edward Davy certainly invented the electric relay in his electric telegraph c.1835, a simple device, which is now called a relay, was included in the original 1840 telegraph patent of Samuel Morse. The mechanism described acted as an amplifier, repeating the telegraph signal. This overcame the problem of limited range of earlier telegraphy schemes, the word relay appears in the context of electromagnetic operations from 1860. The armature is hinged to the yoke and mechanically linked to one or more sets of moving contacts, the armature is held in place by a spring so that when the relay is de-energized there is an air gap in the magnetic circuit. In this condition, one of the two sets of contacts in the relay pictured is closed, and the set is open. Other relays may have more or fewer sets of contacts depending on their function, the relay in the picture also has a wire connecting the armature to the yoke
Relay
–
Automotive-style miniature relay, dust cover is taken off
Relay
–
Simple electromechanical relay.
Relay
–
Latching relay with permanent magnet
Relay
–
Top, middle: reed switches, bottom: reed relay
32.
Kelmscott House
–
Kelmscott House is a Georgian brick mansion at 26 Upper Mall in Hammersmith, overlooking the River Thames. It was the London home of English textile designer, artist, writer, originally called The Retreat, Morris renamed it after the Oxfordshire village of Kelmscott where he had lived at Kelmscott Manor from June 1871. Nearby, Morris began his adventure in printing with his press, the Kelmscott Press. The property was owned by Sir Francis Ronalds family. In 1816, he built the first electric telegraph in its garden, the William Morris Society temporarily re-formed the local branch of the Socialist League to participate in the 2011 London anti-cuts protest. The banner was paraded again on 20 October 2012, William Morris, A Life For Our Time. The William Morris Society UK The William Morris Society in the United States The William Morris Society of Canada
Kelmscott House
–
Kelmscott House
33.
Admiralty
–
The new Admiralty Board meets only twice a year, and the day-to-day running of the Royal Navy is controlled by a Navy Board. It is common for the authorities now in charge of the Royal Navy to be referred to as simply The Admiralty. The title of Lord High Admiral of the United Kingdom was vested in the monarch from 1964 to 2011, the title was awarded to Philip, Duke of Edinburgh by Queen Elizabeth II on his 90th birthday. There also continues to be a Vice-Admiral of the United Kingdom, the office of Admiral of England was created around 1400 although there had already been Admirals of the Northern and Western Seas. In 1546, King Henry VIII established the Council of the Marine, later to become the Navy Board, operational control of the Royal Navy remained the responsibility of the Lord High Admiral, who was one of the nine Great Officers of State. In 1628, Charles I put the office of Lord High Admiral into commission, the office of Lord High Admiral passed a number of times in and out of commission until 1709 after which the office was almost permanently in commission. In 1831, the first Navy Board was abolished as a separate entity, in 1964, the Admiralty along with the War Office and the Air Ministry as separate departments of state were abolished, and re-emerged under one single new Ministry of Defence. Within the expanded Ministry of Defence are the new Admiralty Board which has a separate Navy Board responsible for the running of the Royal Navy. The Army Board and the Air Force Board, each headed by the Secretary of State for Defence, the Board of Admiralty consisted of a number of Lords Commissioners of the Admiralty. The Lords Commissioners were always a mixture of admirals, known as Naval Lords or Sea Lords and Civil Lords, the quorum of the Board was two commissioners and a secretary. The president of the Board was known as the First Lord of the Admiralty, after 1806, the First Lord of the Admiralty was always a civilian while the professional head of the navy came to be known as the First Sea Lord. The first real concerted effort to organise the Admiralty was started by Henry VIII. Between 1860 and 1908 there was no study of strategy and of staff work conducted within the naval service. All the navys talent flowed to the great technical universitys and it was perceived by officials within the Admiralty at this time that the running of war was quite a simple matter for any flag officer who required no formal training. The new War Staff had hardly found its feet and it struggled with the opposition to its existence by senior officers they were categorically opposed to a staff. The deficiencies of the system within this department of state could be seen in the conduct of the Dardanelles campaign, there was no mechanisms in place to answer the big strategic questions in 1914 a Trade Division was created. In 1916, Sir John Jellicoe came to the Admiralty, he organized the staff as following, Chief of War Staff, Operations, Intelligence, Signal Section, Mobilization, Trade. This for the first time gave the naval staff direct representation on the Board, the would direct all operations and movements of the fleet, while the would be responsible for mercantile movements and anti-submarine operations
Admiralty
–
Board of admiralty about 1810.
Admiralty
Admiralty
–
The Admiralty complex in 1794. The colours indicate departments or residences for the several Lords of the Admiralty. The pale coloured extension behind the small courtyard on the left is Admiralty House.
Admiralty
–
Old Admiralty (Ripley Building) in 1760 before addition of the Adam screen
34.
Submarine communications cable
–
A submarine communications cable is a cable laid on the sea bed between land-based stations to carry telecommunication signals across stretches of ocean. The first submarine communications cables, laid in the 1850s, carried telegraphy traffic, subsequent generations of cables carried telephone traffic, then data communications traffic. Modern cables use optical technology to carry digital data, which includes telephone, Internet. Samuel Morse proclaimed his faith in it as early as 1840, and in 1842, he submerged a wire, insulated with tarred hemp and India rubber, in the water of New York Harbor, the following autumn, Wheatstone performed a similar experiment in Swansea Bay. A good insulator to cover the wire and prevent the current from leaking into the water was necessary for the success of a long submarine line. India rubber had been tried by Moritz von Jacobi, the Prussian electrical engineer, another insulating gum which could be melted by heat and readily applied to wire made its appearance in 1842. Gutta-percha, the juice of the Palaquium gutta tree, was introduced to Europe by William Montgomerie. Twenty years earlier, he had seen made of it in Singapore. It was tried on a wire laid across the Rhine between Deutz and Cologne, walker, electrician to the South Eastern Railway, submerged a two-mile wire coated with gutta-percha off the coast from Folkestone, which was tested successfully. It was simply a copper wire coated with gutta-percha, without any other protection, in 1853 further successful cables were laid, linking Great Britain with Ireland, Belgium and the Netherlands, and crossing The Belts in Denmark. The British & Irish Magnetic Telegraph Company completed the first successful Irish link on May 23 between Portpatrick and Donaghadee using the collier William Hutt, the same ship was used for the link from Dover to Ostend in Belgium, by the Submarine Telegraph Company. Meanwhile, the Electric & International Telegraph Company completed two cables across the North Sea, from Orford Ness to Scheveningen, The Netherlands and they were laid by the Monarch, a paddle steamer which later became the first vessel with permanent cable-laying equipment. In 1858 the Steamship Elba was used to lay a Telegraph cable from Jersey to Guernsey, on to Alderney, problems soon developed with eleven breaks occurring by 1860 due to storms, tidal and sand movements and wear on rocks. A report to the Institution of Civil Engineers in 1860 set out the problems to assist in future cable laying operations, the first attempt at laying a transatlantic telegraph cable was promoted by Cyrus West Field, who persuaded British industrialists to fund and lay one in 1858. However, the technology of the day was not capable of supporting the project, it was plagued with problems from the outset, and was in operation for only a month. Subsequent attempts in 1865 and 1866 with the worlds largest steamship, Great Eastern later went on to lay the first cable reaching to India from Aden, Yemen, in 1870. From the 1850s until 1911, British submarine cable systems dominated the most important market, the British had both supply side and demand side advantages. In terms of supply, Britain had entrepreneurs willing to put forth enormous amounts of capital necessary to build, lay, in terms of demand, Britains vast colonial empire led to business for the cable companies from news agencies, trading and shipping companies, and the British government
Submarine communications cable
–
Submarine cables are laid using special
cable layer ships, such as the modern René Descartes, operated by
Orange Marine.
Submarine communications cable
–
A
cross section of the shore-end of a modern submarine communications cable. 1 –
Polyethylene 2 –
Mylar tape 3 – Stranded
steel wires 4 –
Aluminium water barrier 5 –
Polycarbonate 6 –
Copper or aluminium tube 7 –
Petroleum jelly 8 –
Optical fibers
Submarine communications cable
–
A
telegraph stamp of the British & Irish Magnetic Telegraph Co. Limited (c. 1862).
Submarine communications cable
–
Five submarine communication cables crossing the Scottish shore at Scad Head on
Hoy,
Orkney.
35.
Pavel Schilling
–
Baron Pavel Lvovitch Schilling, also known as Paul Schilling, was a diplomat of Baltic German origin employed in the service of Russia in Germany, and who built a pioneering electrical telegraph. It consisted of a single needle system which used a code to indicate the characters in a message. Schillings first electromagnetic telegraph cable line was set up in his apartment in St Petersburg, Schilling was the first to put into practice the idea of a binary system of signal transmissions. Schillings contributions to electrical telegraphy were named an IEEE Milestone in 2009, the most important exhibit in the telegraph collection of the A. S. Popov Central Museum of Communications is reputed to be Schillings telegraph of 1832, a demonstration device was set up in 1835 on an underground line around the Admiralty building. An operational line between Kronstadt and the Peterhof Palace was planned but cancelled after Schillings death, the worldwide history of telecommunications, Wiley-IEEE,2003 ISBN 0-471-20505-2
Pavel Schilling
–
Pavel L'vovitch Shilling
Pavel Schilling
–
Stamp of the
USSR devoted to Pavel Schilling, 1982 (Michel 5200, Scott 5069)
36.
Baron Schilling
–
Baron Pavel Lvovitch Schilling, also known as Paul Schilling, was a diplomat of Baltic German origin employed in the service of Russia in Germany, and who built a pioneering electrical telegraph. It consisted of a single needle system which used a code to indicate the characters in a message. Schillings first electromagnetic telegraph cable line was set up in his apartment in St Petersburg, Schilling was the first to put into practice the idea of a binary system of signal transmissions. Schillings contributions to electrical telegraphy were named an IEEE Milestone in 2009, the most important exhibit in the telegraph collection of the A. S. Popov Central Museum of Communications is reputed to be Schillings telegraph of 1832, a demonstration device was set up in 1835 on an underground line around the Admiralty building. An operational line between Kronstadt and the Peterhof Palace was planned but cancelled after Schillings death, the worldwide history of telecommunications, Wiley-IEEE,2003 ISBN 0-471-20505-2
Baron Schilling
–
Pavel L'vovitch Shilling
Baron Schilling
–
Stamp of the
USSR devoted to Pavel Schilling, 1982 (Michel 5200, Scott 5069)
37.
Silk
–
Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by insect larvae to form cocoons. The best-known silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity, Silk is produced by several insects, but generally only the silk of moth caterpillars has been used for textile manufacturing. There has been research into other types of silk, which differ at the molecular level. Silk is mainly produced by the larvae of insects undergoing complete metamorphosis, Silk production also occurs in Hymenoptera, silverfish, mayflies, thrips, leafhoppers, beetles, lacewings, fleas, flies, and midges. Other types of arthropod produce silk, most notably various arachnids such as spiders, the word silk comes from Old English sioloc, from Greek σηρικός serikos, silken, ultimately from an Asian source. Several kinds of silk, which are produced by caterpillars other than the mulberry silkworm, have been known and used in China, South Asia. However, the scale of production was far smaller than for cultivated silks. Thus, the way to obtain silk suitable for spinning into textiles in areas where commercial silks are not cultivated was by tedious. Commercial silks originate from reared silkworm pupae, which are bred to produce a silk thread with no mineral on the surface. The pupae are killed by either dipping them in boiling water before the adult moths emerge or by piercing them with a needle. These factors all contribute to the ability of the cocoon to be unravelled as one continuous thread. Wild silks also tend to be difficult to dye than silk from the cultivated silkworm. Genetic modification of domesticated silkworms is used to facilitate the production of more types of silk. Silk fabric was first developed in ancient China, the earliest example of silk fabric is from 3630 BC, and it was used as wrapping for the body of a child from a Yangshao culture site in Qingtaicun at Xingyang, Henan. Legend gives credit for developing silk to a Chinese empress, Leizu, because of its texture and lustre, silk rapidly became a popular luxury fabric in the many areas accessible to Chinese merchants. Silk was in demand, and became a staple of pre-industrial international trade. In July 2007, archaeologists discovered intricately woven and dyed silk textiles in a tomb in Jiangxi province, Silk is described in a chapter on mulberry planting by Si Shengzhi of the Western Han
Silk
–
Four of the most important domesticated silk moths. Top to bottom:
Bombyx mori,
Hyalophora cecropia,
Antheraea pernyi,
Samia cynthia. From
Meyers Konversations-Lexikon (1885–1892)
Silk
–
Woven silk textile from tomb no 1. at
Mawangdui in
Changsha,
Hunan province,
China, from the
Western Han Dynasty, 2nd century BC
Silk
–
A painting depicting women inspecting silk, early 12th century, ink and color on silk, by
Emperor Huizong of Song.
Silk
–
Portrait of a silk merchant in Guangzhou,
Qing dynasty, from
Peabody Essex Museum
38.
Yarn
–
Yarn is a long continuous length of interlocked fibres, suitable for use in the production of textiles, sewing, crocheting, knitting, weaving, embroidery, and ropemaking. Thread is a type of yarn intended for sewing by hand or machine, modern manufactured sewing threads may be finished with wax or other lubricants to withstand the stresses involved in sewing. Embroidery threads are yarns specifically designed for hand or machine embroidery, the word yarn comes from Middle English, from the Old English gearn, akin to Old High Germans garn yarn, Greeks chordē string, and Sanskrits hira band. Yarn can be made from a number of natural or synthetic fibers, many types of yarn are made differently though. There are two types of yarn, spun and filament. The most common plant fiber is cotton, which is spun into fine yarn for mechanical weaving or knitting into cloth. Cotton and polyester are the most commonly spun fibers in the world, cotton is grown throughout the world, harvested, ginned, and prepared for yarn spinning. Polyester is extruded from polymers derived from gas and oil. Synthetic fibers are generally extruded in continuous strands of gel-state materials and these strands are drawn, annealed, and cured to obtain properties desirable for later processing. Synthetic fibers come in three forms, staple, tow, and filament. Staple is cut fibers, generally sold in lengths up to 120mm, tow is a continuous rope of fibers consisting of many filaments loosely joined side-to-side. Filament is a continuous strand consisting of anything from 1 filament to many, synthetic fiber is most often measured in a weight per linear measurement basis, along with cut length. Denier and Dtex are the most common weight to length measures, cut-length only applies to staple fiber. Filament extrusion is sometimes referred to as spinning but most people equate spinning with spun yarn production, the most commonly spun animal fiber is wool harvested from sheep. For hand knitting and hobby knitting, thick, wool and acrylic yarns are frequently used, other animal fibers used include alpaca, angora, mohair, llama, cashmere, and silk. More rarely, yarn may be spun from camel, yak, possum, musk ox, cat, dog, wolf, rabbit, or buffalo hair, and even turkey or ostrich feathers. Natural fibers such as these have the advantage of being slightly elastic and very breathable, while trapping a great deal of air, other natural fibers that can be used for yarn include linen and cotton. These tend to be much less elastic, and retain less warmth than the animal-hair yarns, the finished product will also look rather different from the woollen yarns
Yarn
–
Yarn
Yarn
–
Spools of thread
Yarn
–
Cotton being spun
Yarn
–
A full restored and operative primary-level spinning machine taking freshly carded
cotton tails from barrels and spinning them into yarn at the
Quarry Bank Mill in the UK.
39.
Nicholas I of Russia
–
Nicholas I was the Emperor of Russia from 1825 until 1855. He was also the King of Poland and Grand Duke of Finland and his biographer Nicholas V. Riasanovsky says that Nicholas displayed determination, singleness of purpose, and an iron will, along with a powerful sense of duty and a dedication to very hard work. He saw himself as a junior officer totally consumed by spit. A handsome man, he was nervous and aggressive. Trained as an engineer, he was a stickler for minute detail, in his public persona, says Riasanovsky, Nicholas I came to represent autocracy personified, infinitely majestic, determined and powerful, hard as stone, and relentless as fate. His reign had an ideology called Official Nationality that was proclaimed officially in 1833 and it was a reactionary policy based on orthodoxy in religion, autocracy in government, and Russian nationalism. He was the brother of his predecessor, Alexander I. Nicholas inherited his brothers throne despite the failed Decembrist revolt against him and his aggressive foreign policy involved many expensive wars, having a disastrous effect on the empires finances. He was successful against Russias neighbouring southern rivals as he seized the last territories in the Caucasus held by Persia by successfully ending the Russo-Persian War and he ended the Russo-Turkish War successfully as well. Later on, however, he led Russia into the Crimean War with disastrous results, historians emphasize that his micromanagement of the armies hindered his generals, as did his misguided strategy. Fuller notes that historians have concluded that the reign of Nicholas I was a catastrophic failure in both domestic and foreign policy. On the eve of his death, the Russian Empire reached its zenith, spanning over 20 million square kilometers. Nicholas was born at Gatchina Palace in Gatchina to Grand Duke Paul, five months after his birth, his grandmother, Catherine the Great, died and his parents became emperor and empress of Russia. He was a brother of Emperor Alexander I of Russia, who succeeded to the throne in 1801. Riasanovsky says he was, the most handsome man in Europe, Nicholas was not brought up to become the Emperor of Russia, he had two elder brothers. However, as both of them failed to produce sons, Nicholas remained second in the line of succession, in 1825, when Alexander I died suddenly of typhus, Nicholas was caught between swearing allegiance to his second-eldest brother, Constantine Pavlovich, and accepting the throne for himself. The interregnum lasted until Constantine, who was in Warsaw at that time, additionally, on 25 December, Nicholas issued the manifesto proclaiming his accession to the throne. That manifesto retroactively named 1 December, the date of Alexander Is death, during this confusion, a plot was hatched by some members of the military to overthrow Nicholas and to seize power
Nicholas I of Russia
–
Portrait by
Franz Krüger
Nicholas I of Russia
–
Grand Duke Nikolai Pavlovich (ca. 1821).
Nicholas I of Russia
–
Nicholas I "Family Ruble" (1836) depicting the Tsar on the obverse and his family on the reverse:
Tsarina Alexandra Feodorovna (center) surrounded by
Alexander II as
Tsarevich,
Maria,
Olga,
Nicholas,
Michael,
Konstantin, and
Alexandra [2]
Nicholas I of Russia
–
Monument to Nicholas I on
St. Isaac's Square
40.
Peterhof Palace
–
The Peterhof Palace is a series of palaces and gardens located in Petergof, Saint Petersburg, Russia, laid out on the orders of Peter the Great. These palaces and gardens are sometimes referred as the Russian Versailles, the palace-ensemble along with the city center is recognized as a UNESCO World Heritage Site. The dominant natural feature of Peterhof is a sixteen-metre-high bluff lying less than a hundred metres from the shore. The so-called Lower Gardens, at 1.02 km² comprising the part of Peterhofs land area, are confined between this bluff and the shore, stretching east and west for roughly 200 metres. The majority of Peterhofs fountains are contained here, as are several small palaces, East of the Lower Gardens lies the Alexandria Park with 19th-century Gothic Revival structures such as the Kapella. Atop the bluff, near the middle of the Lower Gardens, behind of it are the comparatively small Upper Gardens. Upon the bluffs face below the Palace is the Grand Cascade and this and the Grand Palace are the centrepiece of the entire complex. At its foot begins the Sea Channel, one of the most extensive waterworks of the Baroque period, the Grand Cascade is modelled on one constructed for Louis XIV at his Château de Marly, which is likewise memorialised in one of the parks outbuildings. At the centre of the cascade is a grotto with two stories, faced inside and out with hewn brown stone. It currently contains a modest museum of the fountains history, one of the exhibits is a table carrying a bowl of fruit, a replica of a similar table built under Peters direction. The table is rigged with jets of water that soak visitors when they reach for the fruit, the grotto is connected to the palace above and behind by a hidden corridor. The fountains of the Grand Cascade are located below the grotto and their waters flow into a semicircular pool, the terminus of the fountain-lined Sea Channel. In the 1730s, the large Samson Fountain was placed in this pool and it depicts the moment when Samson tears open the jaws of a lion, representing Russias victory over Sweden in the Great Northern War, and is doubly symbolic. The lion is an element of the Swedish coat of arms, from the lions mouth shoots a 20-metre-high vertical jet of water, the highest in all of Peterhof. This masterpiece by Mikhail Kozlovsky was looted by the invading Germans during the Second World War, a replica of the statue was installed in 1947. Perhaps the greatest technological achievement of Peterhof is that all of the fountains operate without the use of pumps, water is supplied from natural springs and collects in reservoirs in the Upper Gardens. The elevation difference creates the pressure that drives most of the fountains of the Lower Gardens, the Samson Fountain is supplied by a special aqueduct, over four km in length, drawing water and pressure from a high-elevation source. The expanse of the Lower Gardens is designed in the style of french formal gardens of the 17th century
Peterhof Palace
–
Grand Peterhof Palace and the Grand Cascade.
Peterhof Palace
–
Peterhof: the Samson Fountain and Sea Channel.
Peterhof Palace
–
A garden area.
Peterhof Palace
–
French style interior
41.
Kronstadt
–
It is also Saint Petersburgs main seaport. In March 1921, it was the site of the Kronstadt rebellion, traditionally, the seat of the Russian admiralty and the base of the Russian Baltic Fleet were located in Kronstadt guarding the approaches to Saint Petersburg. The historic centre of the city and its fortifications are part of the World Heritage Site Saint Petersburg, Kronstadt has been a place of pilgrimage for Orthodox Christians for many years due to the holy memory of Saint John of Kronstadt. Bus and water tours to Kronstadt are taken daily from Saint Petersburg, Kronstadt was the birthplace of Pyotr Kapitsa, co-recipient of the 1978 Nobel Prize in Physics. Kronstadt was founded by Peter the Great, who took the island of Kotlin from the Swedes in 1703, the first fortifications were inaugurated on May 18,1704. These fortifications, known as Kronstadts Forts, were constructed very quickly, during the winter the Gulf of Finland freezes completely. Workers used thousands of frames made of oak logs filled with stones and these were carried by horses across the frozen sea, and placed in cuttings made in the ice. Thus, several new small islands were created, and forts were erected on them, only two narrow navigable channels remained, and the strongest forts guarded them. Kronstadt was thoroughly refortified in the 19th century, the old three-decker forts, five in number, which formerly constituted the principal defences of the place, and defied the Anglo-French fleets during the Crimean War, became of secondary importance. From the plans of Eduard Totleben a new fort, Constantine, and four batteries were constructed to defend the principal approach, all these fortifications were low and thickly armored earthworks, powerfully armed with heavy Krupp guns in turrets. The town is surrounded with an enceinte, in summer 1891, the French fleet was officially—and triumphantly—received in Kronstadt. It was a first step towards the coming Franco-Russian Alliance, during the Petrograd riots of the February revolution, the sailors of Petrograd joined the revolution and executed their officers, thus gaining a reputation as dedicated revolutionaries. During the civil war, the sailors participated on the red side, until 1921, Kronstadt and the supporting forts and minefields were the key to the protection of Petrograd from foreign forces. Despite this, the cruiser Oleg was torpedoed and sunk by a motor boat after participating in a bombardment of Krasnaya Gorka fort that had revolted against the Bolsheviks. In 1921, a group of officers and sailors, soldiers as well as their civilian supporters rebelled against the Bolshevik government in Soviet Kronstadt. The garrison had previously been a centre of support for the Bolsheviks, and throughout the Civil War of 1917–1921. Their demands included freedom of speech, a stop to the deportation to camps, a change in Soviet war politics. After brief negotiations, Leon Trotsky responded by sending the army to Kronstadt, in the late 1930s, Kronstadt lived the life of the fortified city and was the base of the Baltic Fleet
Kronstadt
–
The Cathedral of St. Andrew (1817–1932), dedicated to the
patron saint of the
Russian Navy. It was destroyed under the Soviet regime in 1932.
Kronstadt
–
Monument to
Peter the Great, the founder of Kronstadt
Kronstadt
–
Kronstadt Bypass canal
42.
Binary coding
–
The base-2 system is a positional notation with a radix of 2. Because of its implementation in digital electronic circuitry using logic gates. Each digit is referred to as a bit, the modern binary number system was devised by Gottfried Leibniz in 1679 and appears in his article Explication de lArithmétique Binaire. Systems related to binary numbers have appeared earlier in multiple cultures including ancient Egypt, China, Leibniz was specifically inspired by the Chinese I Ching. The scribes of ancient Egypt used two different systems for their fractions, Egyptian fractions and Horus-Eye fractions, the method used for ancient Egyptian multiplication is also closely related to binary numbers. This method can be seen in use, for instance, in the Rhind Mathematical Papyrus, the I Ching dates from the 9th century BC in China. The binary notation in the I Ching is used to interpret its quaternary divination technique and it is based on taoistic duality of yin and yang. Eight trigrams and a set of 64 hexagrams, analogous to the three-bit and six-bit binary numerals, were in use at least as early as the Zhou Dynasty of ancient China. The Song Dynasty scholar Shao Yong rearranged the hexagrams in a format that resembles modern binary numbers, the Indian scholar Pingala developed a binary system for describing prosody. He used binary numbers in the form of short and long syllables, Pingalas Hindu classic titled Chandaḥśāstra describes the formation of a matrix in order to give a unique value to each meter. The binary representations in Pingalas system increases towards the right, the residents of the island of Mangareva in French Polynesia were using a hybrid binary-decimal system before 1450. Slit drums with binary tones are used to encode messages across Africa, sets of binary combinations similar to the I Ching have also been used in traditional African divination systems such as Ifá as well as in medieval Western geomancy. The base-2 system utilized in geomancy had long been applied in sub-Saharan Africa. Leibnizs system uses 0 and 1, like the modern binary numeral system, Leibniz was first introduced to the I Ching through his contact with the French Jesuit Joachim Bouvet, who visited China in 1685 as a missionary. Leibniz saw the I Ching hexagrams as an affirmation of the universality of his own beliefs as a Christian. Binary numerals were central to Leibnizs theology and he believed that binary numbers were symbolic of the Christian idea of creatio ex nihilo or creation out of nothing. Is not easy to impart to the pagans, is the ex nihilo through Gods almighty power. In 1854, British mathematician George Boole published a paper detailing an algebraic system of logic that would become known as Boolean algebra
Binary coding
–
Numeral systems
Binary coding
–
Gottfried Leibniz
Binary coding
–
George Boole
43.
Carl Friedrich Gauss
–
Johann Carl Friedrich Gauss was born on 30 April 1777 in Brunswick, in the Duchy of Brunswick-Wolfenbüttel, as the son of poor working-class parents. Gauss later solved this puzzle about his birthdate in the context of finding the date of Easter and he was christened and confirmed in a church near the school he attended as a child. A contested story relates that, when he was eight, he figured out how to add up all the numbers from 1 to 100, there are many other anecdotes about his precocity while a toddler, and he made his first ground-breaking mathematical discoveries while still a teenager. He completed Disquisitiones Arithmeticae, his opus, in 1798 at the age of 21. This work was fundamental in consolidating number theory as a discipline and has shaped the field to the present day, while at university, Gauss independently rediscovered several important theorems. Gauss was so pleased by this result that he requested that a regular heptadecagon be inscribed on his tombstone, the stonemason declined, stating that the difficult construction would essentially look like a circle. The year 1796 was most productive for both Gauss and number theory and he discovered a construction of the heptadecagon on 30 March. He further advanced modular arithmetic, greatly simplifying manipulations in number theory, on 8 April he became the first to prove the quadratic reciprocity law. This remarkably general law allows mathematicians to determine the solvability of any quadratic equation in modular arithmetic, the prime number theorem, conjectured on 31 May, gives a good understanding of how the prime numbers are distributed among the integers. Gauss also discovered that every integer is representable as a sum of at most three triangular numbers on 10 July and then jotted down in his diary the note, ΕΥΡΗΚΑ. On October 1 he published a result on the number of solutions of polynomials with coefficients in finite fields, in 1831 Gauss developed a fruitful collaboration with the physics professor Wilhelm Weber, leading to new knowledge in magnetism and the discovery of Kirchhoffs circuit laws in electricity. It was during this time that he formulated his namesake law and they constructed the first electromechanical telegraph in 1833, which connected the observatory with the institute for physics in Göttingen. In 1840, Gauss published his influential Dioptrische Untersuchungen, in which he gave the first systematic analysis on the formation of images under a paraxial approximation. Among his results, Gauss showed that under a paraxial approximation an optical system can be characterized by its cardinal points and he derived the Gaussian lens formula. In 1845, he became associated member of the Royal Institute of the Netherlands, in 1854, Gauss selected the topic for Bernhard Riemanns Habilitationvortrag, Über die Hypothesen, welche der Geometrie zu Grunde liegen. On the way home from Riemanns lecture, Weber reported that Gauss was full of praise, Gauss died in Göttingen, on 23 February 1855 and is interred in the Albani Cemetery there. Two individuals gave eulogies at his funeral, Gausss son-in-law Heinrich Ewald and Wolfgang Sartorius von Waltershausen and his brain was preserved and was studied by Rudolf Wagner who found its mass to be 1,492 grams and the cerebral area equal to 219,588 square millimeters. Highly developed convolutions were also found, which in the early 20th century were suggested as the explanation of his genius, Gauss was a Lutheran Protestant, a member of the St. Albans Evangelical Lutheran church in Göttingen
Carl Friedrich Gauss
–
Carl Friedrich Gauß (1777–1855), painted by
Christian Albrecht Jensen
Carl Friedrich Gauss
–
Statue of Gauss at his birthplace,
Brunswick
Carl Friedrich Gauss
–
Title page of Gauss's
Disquisitiones Arithmeticae
Carl Friedrich Gauss
–
Gauss's portrait published in
Astronomische Nachrichten 1828
44.
Wilhelm Eduard Weber
–
Wilhelm Eduard Weber was a German physicist and, together with Carl Friedrich Gauss, inventor of the first electromagnetic telegraph. Weber was born in Wittenberg, where his father, Michael Weber, was professor of theology, Wilhelm was the second of three brothers, all of whom were distinguished by an aptitude for science. After the dissolution of the University of Wittenberg his father was transferred to Halle in 1815, Wilhelm had received his first lessons from his father, but was now sent to the Orphan Asylum and Grammar School at Halle. After that he entered the University, and devoted himself to natural philosophy, in 1831, on the recommendation of Carl Friedrich Gauss, he was hired by the university of Göttingen as professor of physics, at the age of twenty-seven. His lectures were interesting, instructive, and suggestive, acoustics was a favourite science of his, and he published numerous papers upon it in Poggendorffs Annalen, Schweiggers Jahrbücher für Chemie und Physik, and the musical journal Carcilia. The mechanism of walking in mankind was another study, undertaken in conjunction with his younger brother and these important investigations were published between the years 1825 and 1838. Gauss and Weber constructed the first electromagnetic telegraph in 1833, which connected the observatory with the institute for physics in Göttingen, in December 1837, the Hannovarian government dismissed Weber, one of the Göttingen Seven, from his post at the university for political reasons. Weber then travelled for a time, visiting England, among countries, and became professor of physics in Leipzig from 1843 to 1849. Weber died in Göttingen, where he is buried in the cemetery as Max Planck. He was elected a member of the Royal Swedish Academy of Sciences in 1855. In 1856 with Rudolf Kohlrausch he demonstrated that the ratio of electrostatic to electromagnetic units produced a number matched the value of the then known speed of light. This finding led to Maxwells conjecture that light is an electromagnetic wave and this also led to Webers development of his theory of electrodynamics. Also, the first usage of the c to denote the speed of light was in an 1856 paper by Kohlrausch. The SI unit of flux, the weber is named after him. German inventors and discoverers Gauss, Carl Friedrich, Weber, Wilhelm Eduard, atlas Des Erdmagnetismus, Nach Den Elementen Der Theorie Entworfen. – obituary Urbanitsky, Alfred, Wormell, Richard, electricity in the Service of Man. – Telegraph of Weber and Gauss Weber, Wilhelm Eduard, Max Planck Institute for the History of Science, Berlin. Jackson, Myles W. Harmonious Triads, Physicists, Musicians, media related to Wilhelm Eduard Weber at Wikimedia Commons Texts on Wikisource, Weber, Wilhelm
Wilhelm Eduard Weber
–
Wilhelm Weber
Wilhelm Eduard Weber
–
Signature
45.
Commutator (electric)
–
It consists of a cylinder composed of multiple metal contact segments on the rotating armature of the machine. The windings on the armature are connected to the commutator segments, Commutators are used in direct current machines, dynamos and many DC motors as well as universal motors. In a motor the commutator applies electric current to the windings, by reversing the current direction in the rotating windings each half turn, a steady rotating force is produced. The first direct current commutator-type machine, the dynamo, was built by Hippolyte Pixii in 1832, Commutators are relatively inefficient, and also require periodic maintenance such as brush replacement. Therefore, commutated machines are declining in use, being replaced by alternating current machines, a commutator consists of a set of contact bars fixed to the rotating shaft of a machine, and connected to the armature windings. As the shaft rotates, the commutator reverses the flow of current in a winding, for a single armature winding, when the shaft has made one-half complete turn, the winding is now connected so that current flows through it in the opposite of the initial direction. In a motor, the current causes the fixed magnetic field to exert a rotational force, or a torque. In a generator, the torque applied to the shaft maintains the motion of the armature winding through the stationary magnetic field. Practical commutators have at least three contact segments, to prevent a dead spot where two brushes simultaneously bridge only two commutator segments, Brushes are made wider than the insulated gap, to ensure that brushes are always in contact with an armature coil. With the remaining arms, a motor can produce sufficient torque to begin spinning the rotor. Two or more fixed brushes connect to the circuit, either a source of current for a motor or a load for a generator. Commutator segments are connected to the coils of the armature, with the number of depending on the speed. Large motors may have hundreds of segments, each conducting segment of the commutator is insulated from adjacent segments. Mica was used on machines and is still used on large machines. Many other insulating materials are used to smaller machines, plastics allow quick manufacture of an insulator, for example. The segments are held onto the shaft using a shape on the edges or underside of each segment. Insulating wedges around the perimeter of each segment are pressed so that the commutator maintains its mechanical stability throughout its operating range. In small appliance and tool motors the segments are typically crimped permanently in place, when the motor fails it is discarded and replaced
Commutator (electric)
–
Commutator in a
universal motor from a vacuum cleaner. Parts: (A) commutator, (B) brush, (C) rotor (
armature) windings, (D)
stator (field) windings, (E) brush guides
Commutator (electric)
Commutator (electric)
Commutator (electric)
46.
Electromagnetic induction
–
Electromagnetic or magnetic induction is the production of an electromotive force across an electrical conductor due to its dynamic interaction with a magnetic field. Michael Faraday is generally credited with the discovery of induction in 1831, Lenzs law describes the direction of the induced field. Faradays law was later generalized to become the Maxwell-Faraday equation, one of the four Maxwells equations in James Clerk Maxwells theory of electromagnetism, electromagnetic induction has found many applications in technology, including electrical components such as inductors and transformers, and devices such as electric motors and generators. Electromagnetic induction was first discovered by Michael Faraday, who made his discovery public in 1831 and it was discovered independently by Joseph Henry in 1832. In Faradays first experimental demonstration, he wrapped two wires around opposite sides of a ring or torus. He plugged one wire into a galvanometer, and watched it as he connected the wire to a battery. He saw a transient current, which he called a wave of electricity and this induction was due to the change in magnetic flux that occurred when the battery was connected and disconnected. Within two months, Faraday found several other manifestations of electromagnetic induction, Faraday explained electromagnetic induction using a concept he called lines of force. However, scientists at the time widely rejected his theoretical ideas, an exception was James Clerk Maxwell, who used Faradays ideas as the basis of his quantitative electromagnetic theory. Heavisides version is the form recognized today in the group of known as Maxwells equations. In 1834 Heinrich Lenz formulated the law named after him to describe the flux through the circuit, Lenzs law gives the direction of the induced EMF and current resulting from electromagnetic induction. Faradays law of induction makes use of the magnetic flux ΦB through a region of space enclosed by a wire loop. The magnetic flux is defined by an integral, Φ B = ∫ Σ B ⋅ d A. The dot product B·dA corresponds to an amount of magnetic flux. In more visual terms, the flux through the wire loop is proportional to the number of magnetic flux lines that pass through the loop. When the flux through the changes, Faradays law of induction says that the wire loop acquires an electromotive force. The direction of the force is given by Lenzs law which states that an induced current will flow in the direction that will oppose the change which produced it. This is due to the sign in the previous equation
Electromagnetic induction
–
Faraday's disk (see
homopolar generator)
Electromagnetic induction
Electromagnetic induction
Electromagnetic induction
47.
Alexander von Humboldt
–
Friedrich Wilhelm Heinrich Alexander von Humboldt was a Prussian geographer, naturalist, explorer, and influential proponent of Romantic philosophy and science. He was the brother of the Prussian minister, philosopher. Humboldts quantitative work on botanical geography laid the foundation for the field of biogeography, Humboldts advocacy of long-term systematic geophysical measurement laid the foundation for modern geomagnetic and meteorological monitoring. Between 1799 and 1804, Humboldt travelled extensively in Latin America and his description of the journey was written up and published in an enormous set of volumes over 21 years. Humboldt was one of the first people to propose that the lands bordering the Atlantic Ocean were once joined and this important work also motivated a holistic perception of the universe as one interacting entity. Alexander von Humboldt was born in Berlin in Prussia on 14 September 1769 and he was baptized as a baby in the Lutheran faith, with the Duke of Brunswick serving as godfather. At age 42, Alexander Georg was rewarded for his services in the Seven Years War with the post of Royal Chamberlain and he profited from the contract to lease state lotteries and tobacco sales. He first married the daughter of Prussian General Adjutant Schweder, in 1766, Alexander Georg married Maria Elisabeth Colomb, a well-educated woman and widow of Baron Hollwede, with whom she had a son. Alexander Georg and Maria Elisabeth had three children, a daughter, who died young, and then two sons, Wilhelm and Alexander and her first-born son, Wilhelms and Alexanders half-brother, was something of a neer do well, not often mentioned in the family history. Alexander Georg died in 1779, leaving the brothers Humboldt in the care of their emotionally distant mother, Humboldts mother expected them to become civil servants of the Prussian state. The money Baron Holwede left to Alexanders mother became, after her death, instrumental in funding Alexanders explorations, due to his youthful penchant for collecting and labeling plants, shells and insects, Alexander received the playful title of the little apothecary. On April 25,1789, he matriculated at Göttingen, then known for the lectures of C. G. Heyne and his brother Wilhelm was already a student at Göttingen, but they did not interact much since their intellectual interests were quite different. His vast and varied interests were by this time fully developed, at Göttingen he met Georg Forster, a naturalist who had been with Captain James Cook on his second voyage. Humboldt traveled with Forster in Europe, the two traveled to England, Humboldts first sea voyage, The Netherlands, and France. In England, he met Sir Joseph Banks, President of the Royal Society, the scientific friendship between Banks and Humboldt lasted until Bankss death in 1820, and the two shared botanical specimens for study. Banks also mobilized his scientific contacts in later years to aid Humboldts work, Humboldts scientific excursion up the Rhine resulted in his 1790 treatise Mineralogische Beobachtungen über einige Basalte am Rhein. Humboldts passion for travel was of long standing, Humboldts talents were devoted to the purpose of preparing himself as a scientific explorer. During this period, his brother Wilhelm married, but Alexander did not attend the nuptials, Humboldt graduated from the Freiberg School of Mines in 1792 and was appointed to a Prussian government position in the Department of Mines as an inspector in Bayreuth and the Fichtel mountains
Alexander von Humboldt
–
Alexander von Humboldt (by
Joseph Stieler, 1843)
Alexander von Humboldt
–
The Tegel Palace (or Humboldt Palace), where Alexander von Humboldt and
Wilhelm von Humboldt lived for several years.
Alexander von Humboldt
–
Portrait of Alexander von Humboldt by Friedrich Georg Weitsch, 1806
Alexander von Humboldt
–
Geography of Plants, 1805.
48.
Carl August Steinheil
–
Carl August von Steinheil was a German physicist, inventor, engineer and astronomer. Steinheil was born in Ribeauvillé, Alsace and he studied law in Erlangen since 1821. He then studied astronomy in Göttingen and Königsberg and he continued his studies in astronomy and physics while living in his fathers manor in Perlachseck near Munich. From 1832 to 1849, Steinheil was professor for mathematics and physics at the University of Munich, the pictures produced were round with a diameter of 4 cm, the method was later named the “Steinheil method. ”It was the first daguerreotype in Germany. In 1846, Steinheil travelled to Naples to install a new system for weight, three years later, he was appointed to the Board of Telegraphy of the Austrian Trade Ministry. Steinheil was tasked with designing a network for the entire empire. In 1851, he started the Swiss telegraph network, Steinheil returned Munich as konservator of the mathematical-physical collections and ministerial secretary in the Trade Ministry of Bavaria. In 1854, he founded C. A. Steinheil & Söhne, the company built telescopes, spectroscopes and photometers – one of Steinheils inventions, used to measure brightness. Steinheil & Söhne produced large telescopes for observatories in Uppsala, Mannheim, Leipzig, the company also produced refractors and reflectors with silver-covered mirrors. The process for creating the silvering was developed by Steinheils friend Justus Liebig, in 1862, Steinheils sons starting managing the company. Steinheil died in Munich in Bavaria on 14 September 1870 and he was buried in the Alter Südfriedhof cemetery. Some sources state that Steinheilite, a transparent mineral that resembles blue quartz but is actually a form of iolite, was named after Carl von Steinheil, Carl August von Steinheil in the German National Library catalogue
Carl August Steinheil
–
Carl August von Steinheil
Carl August Steinheil
–
Reading telescopes by C.A. Steinheil purchased in 1865 on display in the
Teylers Instrument Room
49.
Munich
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Munich is the capital and largest city of the German state of Bavaria, on the banks of River Isar north of the Bavarian Alps. Munich is the third largest city in Germany, after Berlin and Hamburg, the Munich Metropolitan Region is home to 5.8 million people. According to the Globalization and World Rankings Research Institute Munich is considered an alpha-world city, the name of the city is derived from the Old/Middle High German term Munichen, meaning by the monks. It derives from the monks of the Benedictine order who ran a monastery at the place that was later to become the Old Town of Munich, Munich was first mentioned in 1158. From 1255 the city was seat of the Bavarian Dukes, black and gold—the colours of the Holy Roman Empire—have been the citys official colours since the time of Ludwig the Bavarian, when it was an imperial residence. Following a final reunification of the Wittelsbachian Duchy of Bavaria, previously divided and sub-divided for more than 200 years, like wide parts of the Holy Roman Empire, the area recovered slowly economically. In 1918, during the German Revolution, the house of Wittelsbach, which governed Bavaria since 1180, was forced to abdicate in Munich. In the 1920s, Munich became home to political factions, among them the NSDAP. During World War II, Munich was heavily bombed and more than 50% of the entire city, the postwar period was characterised by American occupation until 1949 and a strong increase of population and economic power during the years of the Wirtschaftswunder after 1949. The city is home to corporations like BMW, Siemens, MAN, Linde, Allianz and MunichRE as well as many small. Munich is home to national and international authorities, major universities, major museums. Its numerous architectural attractions, international events, exhibitions and conferences. Munich is one of the most prosperous and fastest growing cities in Germany and it is a top-ranked destination for migration and expatriate location, despite being the municipality with the highest density of population in Germany. Munich nowadays hosts more than 530,000 people of foreign background, the year 1158 is assumed to be the foundation date, which is the earliest date the city is mentioned in a document. The document was signed in Augsburg, by that time the Guelph Henry the Lion, Duke of Saxony and Bavaria, had built a bridge over the river Isar next to a settlement of Benedictine monks—this was on the Old Salt Route and a toll bridge. In 1175, Munich was officially granted city status and received fortification, in 1180, with the trial of Henry the Lion, Otto I Wittelsbach became Duke of Bavaria and Munich was handed over to the Bishop of Freising. In 1240, Munich was transferred to Otto II Wittelsbach and in 1255, Duke Louis IV, a native of Munich, was elected German king in 1314 and crowned as Holy Roman Emperor in 1328. He strengthened the position by granting it the salt monopoly
Munich
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From left to right: The
Munich Frauenkirche, the
Nymphenburg Palace, the
BMW Headquarters, the
New Town Hall, the
Munich Hofgarten and the
Allianz Arena.
Munich
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Munich city
coat of arms
Munich
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Banners with the colours of Munich (left) and Bavaria (right) with the
Frauenkirche in the background
Munich
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Bombing damage to the Altstadt. Note the roofless and pockmarked Altes Rathaus looking up the Tal. The roofless Heilig-Geist-Kirche is on the right of the photo. Its spire, without the copper top, is behind the church. The Talbruck gate tower is missing completely.
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David Alter
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David Alter was a prominent American inventor and scientist of the 19th century. He was born in Westmoreland County, Pennsylvania and graduated from the Reformed Medical School in New York City and he had German and Swiss ancestry. Dr. David Alter is credited with having invented,1836 - the electric telegraph,1840 - his electric buggy - the forerunner of the automobile. 1845 - a patented method to manufacture and purify bromine from salt wells, highly useful in the iron industry,1854 - spectrum analysis, the idea that every element has its own emission spectrum, a breakthrough development in spectroscopy. The published article was, On Certain Physical Properties of Light Produced by the Combustion of Different Metals in an Electric Spark Refracted by a Prism. He included a chart of the lines or bands of twelve metals and paved the way by showing the spectral lines of brass corresponded to copper. 1855 - an expansion of spectrum analysis to include the properties of gas. These discoveries were later implemented and included by Gustav Kirchhoff and Robert Bunsen in the Three Laws of Spectroscopy,1858 - a patented method to extract oil from coal and shale, along with a partner Samuel Hill. Their invention sped manufacturing, but was replaced by technology in a few years, a short range type of telephone - forerunner of the Graham Bell telephone. Dr. David Alter was a doctor, scientist, and famous American inventor, son of John Alter, David began as a physician and scientist in Elderton, Pennsylvania in the 1830s. David Alter married Laura Rowley, and they settled in Elderton, in 1836 Elderton, David Alter invented the electric telegraph, one year before the popular Morse telegraph was invented. David rigged the telegraph between his house and his barn, David Alter obtained medical schooling at the Reformed Medical College in New York City, and at the Cincinnati Medical School. David Alter settled in Freeport, Pennsylvania about 1837, david’s first wife Laura died in 1842, and several years later he married her sister, Amanda Rowley. He had a total of thirteen children and he manufactured bromine near his home, manned a weather station, worked as a physician, and was one of the first daguerreotype photographers of the town of Freeport. Inventions while in Freeport, In the great Pittsburgh Fire of 1845 and he went on to discover Spectral Analysis in 1853. He also invented and patented a method of manufacturing Bromine from salt wells in 1845, dr. Alter resided in Freeport until his death in 1881. Published Biographies, Albert, George Dallas, editor, history of the County of Westmoreland. Philadelphia PA, L. H. Everts and Company,1882, biographical and Historical Cyclopedia of Indiana and Armstrong Counties
David Alter
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Portrait of Dr. David Alter, printed in the book History of the County of Westmoreland, Pennsylvania (1882).
"Telegraph". New International Encyclopedia. 1905.
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