Charles Babbage - Wikipedia, the Free Encyclopedia
Total Page:16
File Type:pdf, Size:1020Kb
Charles Babbage - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Charles_Babbage Charles Babbage 1 of 7 Sunday 16 May 2010 12:49 PM Charles Babbage - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Charles_Babbage From Wikipedia, the free encyclopedia Charles Babbage, FRS (26 December 1791 – 18 October 1871)[2] was an English Charles Babbage mathematician, philosopher, inventor, and mechanical engineer who originated the concept of a programmable computer.[3] Parts of his uncompleted mechanisms are on display in the London Science Museum. In 1991, a perfectly functioning difference engine was constructed from Babbage's original plans. Built to tolerances achievable in the 19th century, the success of the finished engine indicated that Babbage's machine would have worked. Nine years later, the Science Museum completed the printer Babbage had designed for the difference engine, an astonishingly complex device for the 19th century. Considered a "father of the computer",[4] Babbage is credited with inventing the first mechanical computer that eventually led to more complex designs. Contents 1 Birth The Illustrated London News (4 November 2 Education 1871).[1] 3 Marriage, family, death 4 Design of computers Born 25 December 1792 4.1 Difference engine London, England 4.1.1 Completed models Died 18 October 1871 (aged 79) Marylebone, London, England 4.2 Analytical engine Nationality 4.3 Modern adaptations United Kingdom Fields Mathematics, analytical 5 Other accomplishments philosophy, computer science 6 Eccentricities Institutions Trinity College, Cambridge 7 Quotations 8 Commemoration Alma mater Peterhouse, Cambridge 9 Publications Known for Mathematics, computing. 10 References Signature 11 External links Birth Babbage's birthplace is disputed, but he was most likely born at 44 Crosby Row, Walworth Road, London, England. A blue plaque on the junction of Larcom Street and Walworth Road commemorates the event. His date of birth was given in his obituary in The Times as 25 December 1792. However after the obituary appeared, a nephew wrote to say that Charles Babbage was born one year earlier, in 1791. The parish register of St. Mary's Newington, London, shows that Babbage was baptised on 6 January 1792, supporting a birth year of 1791.[5][6][7] Babbage's father, Benjamin Babbage, was a banking partner of the Praeds who owned the Bitton Estate in Teignmouth. His mother was Betsy Plumleigh Teape. In 1808, the Babbage family moved into the old Rowdens house in East Teignmouth, and Benjamin Babbage became a warden of the nearby St. Michael’s Church. Education His father's money allowed Charles to receive instruction from several schools and tutors during the course of his elementary education. Around the age of eight he was sent to a country school in Alphington near Exeter to recover from a life-threatening fever. His parents ordered that his "brain was not to be taxed too much" and Babbage felt that "this great idleness may have led to some of my childish reasonings." For a short time he attended King Edward VI Grammar School in Totnes, South Devon, but his health forced him back to private tutors for a time.[8] He then joined a 30-student Holmwood academy, in Baker Street, Enfield, Middlesex under Reverend Stephen Freeman. The academy had a well-stocked library that prompted Babbage's love of mathematics. He studied with two more private tutors after leaving the academy. Of the first, a clergyman near Cambridge, Babbage said, "I fear I did not derive from it all the advantages that I might have done." The second was an Oxford tutor from whom Babbage learned enough of the Classics to be accepted to Cambridge. Babbage arrived at Trinity College, Cambridge in October 1810.[9] He had read extensively in Leibniz, Joseph Louis Lagrange, Thomas Simpson, and Lacroix and was seriously disappointed in the mathematical instruction available at Cambridge. In response, he, John Herschel, George Peacock, and several other friends formed the Analytical Society in 1812. Babbage, Herschel, and Peacock were also close friends with future judge and patron of science Edward Ryan. Babbage and Ryan married two sisters.[10] As a student, Babbage was also a member of other societies such as the Ghost Club, concerned with investigating supernatural phenomena, and the Extractors Club, dedicated to liberating its members from the madhouse, should any be committed to one.[11][12] In 1812 Babbage transferred to Peterhouse, Cambridge.[9] He was the top mathematician at Peterhouse, but did not graduate with honours. He instead received an honorary degree without examination in 1814. Marriage, family, death 2 of 7 Sunday 16 May 2010 12:49 PM Charles Babbage - Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Charles_Babbage On 25 July 1814, Babbage married Georgiana Whitmore at St. Michael's Church in Teignmouth, Devon. The couple lived at Dudmaston Hall,[13] Shropshire (where Babbage engineered the central heating system), before moving to 5 Devonshire Street, Portland Place, London. Charles and Georgiana had eight children,[14] but only three — Benjamin Herschel, Georgiana Whitmore, and Henry Prevost — survived to adulthood. Georgiana died in Worcester on 1 September 1827. Charles' father, wife, and at least one son all died in 1827. These deaths caused Babbage to go into a mental breakdown which delayed the construction of his machines. His youngest son, Henry Prevost Babbage (1824–1918), went on to create six working difference Grave of Charles Babbage engines based on his father's designs,[15] one of which was sent to Harvard University where it was later at Kensal Green Cemetery discovered by Howard H. Aiken, pioneer of the Harvard Mark I. Henry Prevost's 1910 Analytical Engine Mill, previously on display at Dudmaston Hall, is now on display at the Science Museum.[16] Charles Babbage died at age 79 on 18 October 1871, and was buried in London's Kensal Green Cemetery. According to Horsley, Babbage died "of renal inadequacy, secondary to cystitis."[17] In 1983 the autopsy report for Charles Babbage was discovered and later published by one of his descendants.[18][19] A copy of the original is also available.[20] Half of Babbage's brain is preserved at the Hunterian Museum in the Royal College of Surgeons in London.[21][22] Design of computers Babbage sought a method by which mathematical tables could be calculated mechanically, removing the high rate of human error. Three different factors seem to have influenced him: a dislike of untidiness; his experience working on logarithmic tables; and existing work on calculating machines carried out by Wilhelm Schickard, Blaise Pascal, and Gottfried Leibniz. He first discussed the principles of a calculating engine in a letter to Sir Humphry Davy in 1822. Babbage's machines were among the first mechanical computers, although they were not actually completed, largely because of funding problems and personality issues. He directed the building of some steam-powered machines that achieved some success, suggesting that calculations could be mechanised. Although Babbage's machines were mechanical and unwieldy, their basic architecture was very similar to a modern computer. The data and program memory were separated, operation was instruction based, the control unit could make conditional jumps and the machine had a separate I/O unit. Difference engine Main article: Difference engine Part of Babbage's difference engine, assembled after his In Babbage’s time, numerical tables were calculated by humans who were called ‘computers’, meaning death by Babbage's son, "one who computes", much as a conductor is "one who conducts". At Cambridge, he saw the high using parts found in his error-rate of this human-driven process and started his life’s work of trying to calculate the tables laboratory. mechanically. He began in 1822 with what he called the difference engine, made to compute values of polynomial functions. Unlike similar efforts of the time, Babbage's difference engine was created to calculate a series of values automatically. By using the method of finite differences, it was possible to avoid the need for multiplication and division. The first difference engine was composed of around 25,000 parts, weighed fifteen tons (13,600 kg), and stood 8 ft (2.4 m) high. Although he received ample funding for the project, it was never completed. He later designed an improved version, "Difference Engine No. 2", which was not constructed until 1989–1991, using Babbage's plans and 19th century manufacturing tolerances. It performed its first calculation at the London Science Museum returning results to 31 digits, far more than the average modern pocket calculator. Completed models The London Science The London Science Museum has constructed two Difference Engines, according to Babbage's plans for Museum's Difference the Difference Engine No 2. One is owned by the museum; the other, owned by technology millionaire [23] Engine #2, built from Nathan Myhrvold, went on exhibit at the Computer History Museum in Mountain View, California on [24] Babbage's design. 10 May 2008. The two models that have been constructed are not replicas; until the assembly of the first Difference Engine No 2 by the London Science Museum, no model of the Difference Engine No 2 existed. Analytical engine Main article: Analytical engine Soon after the attempt at making the difference engine crumbled, Babbage started designing a different, more complex machine called the Analytical Engine. The engine is not a single physical machine but a succession of designs that he tinkered with until his death in 1871. The main difference between the two engines is that the Analytical Engine could be programmed using punched cards. He realized that programs could be put on these cards so the person had only to create the program initially, and then put the cards in the machine and let it run.