Albert Einstein (pronounced /ˈælbərt ˈaɪnstaɪn/; German: [ˈalbɐt ˈaɪ̯nʃtaɪ̯n] (
Einstein is best known for his theories of special relativity and general relativity. He received the 1921 Nobel Prize in Physics “for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect.”[2]
Einstein published more than 300 scientific and over 150 non-scientific works.[3] He is often regarded as the father of modern physics.[citation needed]
By 1874, Bell's initial work on the harmonic telegraph had entered a formative stage with progress it made both at his new Boston "laboratory" (a rented facility) as well as at his family home in Canada a big success.[50] While working that summer in Brantford, Bell experimented with a "phonautograph," a pen-like machine that could draw shapes of sound waves on smoked glass by tracing their vibrations. Bell thought it might be possible to generate undulating electrical currents that corresponded to sound waves.[51] Bell also thought that multiple metal reeds tuned to different frequencies like a harp would be able to convert the undulatory currents back into sound. But he had no working model to demonstrate the feasibility of these ideas.[52]
In 1874, telegraph message traffic was rapidly expanding and in the words of Western Union President William Orton, had become "the nervous system of commerce". Orton had contracted with inventors Thomas Edison and Elisha Gray to find a way to send multiple telegraph messages on each telegraph line to avoid the great cost of constructing new lines.[53] When Bell mentioned to Gardiner Hubbard and Thomas Sanders that he was working on a method of sending multiple tones on a telegraph wire using a multi-reed device, the two wealthy patrons began to financially support Bell's experiments.[54] Patent matters would be handled by Hubbard's patent attorney, Anthony Pollok.[55]
In March 1875, Bell and Pollok visited the famous scientist Joseph Henry, who was then director of the Smithsonian Institution, and asked Henry's advice on the electrical multi-reed apparatus that Bell hoped would transmit the human voice by telegraph. Henry replied that Bell had "the germ of a great invention". When Bell said that he did not have the necessary knowledge, Henry replied, "Get it!" That declaration greatly encouraged Bell to keep trying, even though he did not have the equipment needed to continue his experiments, nor the ability to create a working model of his ideas. However, a chance meeting in 1874 between Bell and Thomas A. Watson, an experienced electrical designer and mechanic at the electrical machine shop of Charles Williams, changed all that.
With financial support from Sanders and Hubbard, Bell was able to hire Thomas Watson as his assistant and the two of them experimented with acoustic telegraphy. On 2 June 1875, Watson accidentally plucked one of the reeds and Bell, at the receiving end of the wire, heard the overtones of the reed; overtones that would be necessary for transmitting speech. That demonstrated to Bell that only one reed or armature was necessary, not multiple reeds. This led to the "gallows" sound-powered telephone, which was able to transmit indistinct, voice-like sounds, but not clear speech.
Alexander Graham Bell (March 3, 1847 – August 2, 1922) was an eminent scientist, inventor, engineer and innovator who is credited with inventing the first practical telephone.
Bell's father, grandfather, and brother had all been associated with work on elocution and speech, and both his mother and wife were deaf, profoundly influencing Bell's life's work.[1] His research on hearing and speech further led him to experiment with hearing devices which eventually culminated in Bell being awarded the first U.S. patent for the telephone in 1876.[2] In retrospect, Bell considered his most famous invention an intrusion on his real work as a scientist and refused to have a telephone in his study.[3]
Many other inventions marked Bell's later life, including groundbreaking work in optical telecommunications, hydrofoils and aeronautics. In 1888, Alexander Graham Bell became one of the founding members of the National Geographic Society.[4]
Einstein’s early papers all come from attempts to demonstrate that atoms exist and have a finite nonzero size. At the time of his first paper in 1902, it was not yet completely accepted by physicists that atoms were real, even though chemists had good evidence ever since Antoine Lavoisier’s work a century earlier. The reason physicists were skeptical was because no 19th century theory could fully explain the properties of matter from the properties of atoms.
Ludwig Boltzmann was a leading 19th century atomist physicist, who had struggled for years to gain acceptance for atoms. Boltzmann had given an interpretation of the laws of thermodynamics, suggesting that the law of entropy increase is statistical. In Boltzmann’s way of thinking, the entropy is the logarithm of the number of ways a system could be configured inside. The reason the entropy goes up is only because it is more likely for a system to go from a special state with only a few possible internal configurations to a more generic state with many. While Boltzmann’s statistical interpretation of entropy is universally accepted today, and Einstein believed it, at the turn of the 20th century it was a minority position.
The statistical idea was most successful in explaining the properties of gases. James Clerk Maxwell, another leading atomist, had found the distribution of velocities of atoms in a gas, and derived the surprising result that the viscosity of a gas should be independent of density. Intuitively, the friction in a gas would seem to go to zero as the density goes to zero, but this is not so, because the mean free path of atoms becomes large at low densities. A subsequent experiment by Maxwell and his wife confirmed this surprising prediction. Other experiments on gases and vacuum, using a rotating slitted drum, showed that atoms in a gas had velocities distributed according to Maxwell’s distribution law.
In addition to these successes, there were also inconsistencies. Maxwell noted that at cold temperatures, atomic theory predicted specific heats that are too large. In classical statistical mechanics, every spring-like motion has thermal energy kBT on average at temperature T, so that the specific heat of every spring is Boltzmann’s constant kB. A monatomic solid with N atoms can be thought of as N little balls representing N atoms attached to each other in a box grid with 3N springs, so the specific heat of every solid is 3NkB, a result which became known as the Dulong-Petit law. This law is true at room temperature, but not for colder temperatures. At temperatures near zero, the specific heat goes to zero.
Similarly, a gas made up of a molecule with two atoms can be thought of as two balls on a spring. This spring has energy kBT at high temperatures, and should contribute an extra kB to the specific heat. It does at temperatures of about 1000 degrees, but at lower temperature, this contribution disappears. At zero temperature, all other contributions to the specific heat from rotations and vibrations also disappear. This behavior was inconsistent with classical physics.
The most glaring inconsistency was in the theory of light waves. Continuous waves in a box can be thought of as infinitely many spring-like motions, one for each possible standing wave. Each standing wave has a specific heat of kB, so the total specific heat of a continuous wave like light should be infinite in classical mechanics. This is obviously wrong, because it would mean that all energy in the universe would be instantly sucked up into light waves, and everything would slow down and stop.
These inconsistencies led some people to say that atoms were not physical, but mathematical. Notable among the skeptics was Ernst Mach, whose logical positivist philosophy led him to demand that if atoms are real, it should be possible to see them directly.[29] Mach believed that atoms were a useful fiction, that in reality they could be assumed to be infinitesimally small, that Avogadro’s number was infinite, or so large that it might as well be infinite, and kB was infinitesimally small. Certain experiments could then be explained by atomic theory, but other experiments could not, and this is the way it will always be.
Einstein opposed this position. Throughout his career, he was a realist. He believed that a single consistent theory should explain all observation, and that this theory would be a description what was really going on, underneath it all. So he set out to show that the atomic point of view was correct. This led him first to thermodynamics, then to statistical physics, and to the theory of specific heats of solids.
In 1905, while he was working in the patent office, the leading German language physics journal Annalen der Physik published four of Einstein’s papers. The four papers eventually were recognized as revolutionary, and 1905 became known as Einstein’s "Miracle Year", and the papers, as the Annus Mirabilis Papers.
Watt was buried in the grounds of St. Mary's Church, Handsworth, in Birmingham. Later expansion of the church, over his grave, means that his tomb is now buried inside the church. A statue of him, Boulton and Murdoch is in Birmingham, as are five other statues of him alone, one in Chamberlain Square, the other outside the Law Courts. He is also remembered by the Moonstones and a school is named in his honour, both in Birmingham. An extensive archive of his papers is held at Birmingham Central Library. Matthew Boulton's home, Soho House, is now a museum, commemorating the work of both men. The University of Glasgow's Faculty of Engineering, the oldest in the United Kingdom, (where Watt was a professor) has its headquarters in the James Watt Building, which also houses the department of Mechanical Engineering and the department of Aerospace Engineering.
The location of James Watt's birth in Greenock is commemorated by a statue, close to his birthplace. Several locations and street names in Greenock recall him, most notably the Watt Memorial Library, which was begun in 1816 with Watt's donation of scientific books, and developed as part of the Watt Institution by his son (which ultimately became the James Watt College). Taken over by the local authority in 1974, the library now also houses the local history collection and archives of Inverclyde, and is dominated by a large seated statue in the vestibule. Watt is additionally commemorated by statuary in George Square, Glasgow and Princes Street, Edinburgh.
The James Watt College has expanded from its original location to include campuses in Kilwinning (North Ayrshire), Finnart Street and The Waterfront in Greenock, and the Sports campus in Largs. Heriot-Watt University near Edinburgh was at one time the School of Arts of Edinburgh, founded in 1821 as the world’s first Mechanics Institute, but to commemorate George Heriot, the 16th century financier to King James, and James Watt, after Royal Charter the name was changed to Heriot-Watt University. Dozens of university and college buildings (chiefly of science and technology) are named after him.
The huge painting James Watt contemplating the steam engine by James Eckford Lauder is now owned by the National Gallery of Scotland.
Watt was ranked first, tying with Edison, among 229 significant figures in the history of technology by Charles Murray's survey of historiometry presented in his book Human Accomplishments. Watt was ranked 22nd in Michael H. Hart's list of the most influential figures in history.
Over 50 roads or streets in the UK are named after him.
A colossal statue of Watt by Chantrey was placed in Westminster Abbey, and later was moved to St. Paul's Cathedral. On the cenotaph the inscription reads:
A lecture theatre in the Mechanical & Manufacturing Engineering building at the University of Birmingham is named "G31 - The James Watt Lecture Theatre".
On 29 May 2009, the Bank of England announced that Watt would appear on a new £50 note, alongside Matthew Boulton.[6James Watt's improvements transformed the Newcomen engine, which had hardly changed for fifty years, and initiated changes in generating and applying power, which transformed the world of work, and were a key innovation of the Industrial Revolution. The importance of the invention can hardly be overstated—it gave us the modern world. A key feature of it was that it brought the engine out of the remote coal fields into factories where many mechanics, engineers, and even tinkerers were exposed to its virtues and limitations. It was a platform for generations of inventors to improve. It was clear to many that higher pressures produced in improved boilers would produce engines having even higher efficiency, and would lead to the revolution in transportation that was soon embodied in the locomotive and steamboat. It made possible the construction of new factories that, since they were not dependent on water power, could work the year round, and could be placed almost anywhere. Work was moved out of the cottages, resulting in economies of scale. Capital could work more efficiently, and manufacturing productivity greatly improved. It made possible the cascade of new sorts of machine tools that could be used to produce better machines, including that most remarkable of all of them, the Watt steam engine.
Of Watt, the English Novelist Aldous Huxley (1894-1963) wrote; "To us, the moment 8:17 A.M. means something - something very important, if it happens to be the starting time of our daily train. To our ancestors, such an odd eccentric instant was without significance - did not even exist. In inventing the locomotive, Watt and Stephenson were part inventors of time."
