\chapter{The Faces of Computing: \\Ada Lovelace}

Computer science is strongly allied with mathematics, and the face of both of those fields is often a white male face. While it's true that both of these fields have traditionally been the domain of white males, many women and minorities have contributed to both mathematics and computer science over the years. 

Ada Lovelace, otherwise known as Augusta Ada King, Countess of Lovelace, was one of the women who made significant contributions to both fields. 

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\caption{Detail of Margaret Sarah Carpenter's portrait of Ada Lovelace}
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Lovelace was the child of the English poet Lord Byron and reformer Anne Isabella Milbanke. This period in English history is especially fascinating to me, as Lord Byron was in a social circle that included his wife, his daughter, and the poet Percy Bysshe Shelley and his wife Mary Shelley (who was the daughter of Mary Wollstonecraft, an early feminist and advocate of women's rights, and William Godwin, who had many not-so-nice things to say about aristocracy. This circle would eventually lead to the production of \textit{Dracula} by Bram Stoker, \textit{Frankenstein, or the Modern Prometheus} by Mary Shelley, the modern computer algorithm and by extension, the modern computer industry, and many, many great horror films.

Lady Byron (i.e., Anne Isabella Noel Byron, 11th Baroness Wentworth and Baroness Byron) was an interesting personality herself. She was an educational reformer and philanthropist, in addtion to being an abolitionist. She established the Ealing Grove School, the first industrial school in England. At this school, academic subjects were combined with three hours of gardening each day, and corporal punishment was not allowed. (Corporal punishment in elementary school was still a thing when I was a student in the 1970s.) 

Ada showed an early interest in mathematics, and her mother encouraged this in an effort to ward off the development of what she perceived as Lord Byron's insanity.(This was, after all, an age which did not have a good understanding of mental illness. We are doing better in this regard, but we still have quite a way to go.) At the age of eighteen, she began a long working relationship and friendship with Charles Babbage, the British mathematician. At the time, Babbage used to host a ``Saturday night soirée'' which was often attended by the cultural elite, including Charles Dickens, Michael Farday (an early pioneer in the study of electromagnetism), Henry Fox Talbot (a photography pioneer who invented the calotype process, an early precursor to modern photography), and Charles Wheatstone (who was a pioneer in the study of electricity, invented the English concertina, and also invented the Playfair cypher, which was the first cipher to encrypt pairs of letters, rather than individual letters). 

That's a pretty impressive crowd to hange out with on Saturday nights.

It was at one of these soirées that Babbage introduced his ``Difference Engine'' which was a mechanical computing device that was designed to tabulate logarithms and trigonometric functions by evaluting finite differences to approximate polynomials. Although this device was never fully built, it led Babbage to realize that a much more general design, the ``Analytical Engine'', which incorporated an arithmetic logic unit (i.e., a circuit that performs arithmetic on integer binary numbers), integrated memory, and control flow in the form of conditional branching (i.e., \texttt{if-then-else} and loops (i.e., \texttt{for-next}).

There are a couple of things to note about Babbage's Analytical Engine. First, it was never built (Babbage had a lot of disagreements with his chief engineer\footnote{In his later life, he campaigned to make street musicians illegal, so he seems like a difficult person to get along with. (See \textit{Nineteenth-Century Science: An Anthology} edited by A.S. Weber and published by Broadview Press in 2000 for the few details that exist.)} and had difficulty funding its development,\footnote{By 1842, the British government had already given him £17,000—the modern day equivalent of almost £1,700,000 (see \kref{https://inflationhistory.com/en-US/?currency=GBP&amount=17000&year=1842}{https://inflationhistory.com/en-US/?currency=GBP\&am\\ount=17000\&year=1842})—to fund the development of his Difference Engine, which was only partially built and then abandoned when he moved on to the Analystical Engine.} so it was an entirely theoretical construct. Second, it was considered to be the world's first Turing complete computer, which is pretty impressive for a 19th century device.\footnote{An interesting, modern\textit{ish} aside: In 1984, James McCurry and Gary M. Kusin started a software retailer in Dallas (Texas, US) called ``Babbage's'' named after Charles Babbage himself. They eventually sold more video games than software and in 1994 merged with a Minnesota based company called Software Etc. to form a new company called NeoStar Retail Group (which is about as clunky a name as you can possibly come up with). The company went through several more changes—bankruptcy, being purchased by Barnes \& Noble, a merger with the B\&N owned Funco) before eventually being spun off through an intial public offering in 2002 to become—you guessed it—GameStop.}

There are a lot of technical details behind what it means for a computing device to be Turing complete, but it basically boils down to its capabilities. A Turing complete device means that you can program it to find any answer, provided you have unlimited runtime and memory\footnote{Because no computer has unlimited runtime or memory, no device is \textit{truly} Turing complete—as Captain Barbossa said, it's more of a guideline than a rule.}. Your computer is Turing complete, whereas your calculator and kitchen timer are not. The Difference Engine was not Turing complete because its intended output (and what the British government wanted and was willing to give Babbage so much money for) was tables of logarithms and trigonometric functions, but that was all that it could produce. The Analytical Engine had the same basic structure as modern computer design, albeit in a larger, clunkier fashion.

The fact that it was Turing complete meant that it had a \textit{lot} of potential, and Ada Lovelace was the first person to figure out a way to tap that potential. 

\texttt{From wikipedia; rewrite}

Though Babbage's Analytical Engine was never constructed and exercised no influence on the later invention of electronic computers, it has been recognised in retrospect as a Turing-complete general-purpose computer which anticipated the essential features of a modern electronic computer; Babbage is therefore known as the "father of computers," and Lovelace is credited with several computing "firsts" for her collaboration with him.

Between 1842 and 1843, Lovelace translated an article by the military engineer Luigi Menabrea (later Prime Minister of Italy) about the Analytical Engine, supplementing it with seven long explanatory notes. These notes described a method of using the machine to calculate Bernoulli numbers which is often called the first published computer program.

She also developed a vision of the capability of computers to go beyond mere calculating or number-crunching, while many others, including Babbage himself, focused only on those capabilities. Lovelace was the first to point out the possibility of encoding information besides mere arithmetical figures, such as music, and manipulating it with such a machine. Her mindset of "poetical science" led her to ask questions about the Analytical Engine (as shown in her notes), examining how individuals and society relate to technology as a collaborative tool.

Throughout her life, Lovelace was strongly interested in scientific developments and fads of the day, including phrenology and mesmerism. After her work with Babbage, Lovelace continued to work on other projects. In 1844, she commented to a friend Woronzow Greig about her desire to create a mathematical model for how the brain gives rise to thoughts and nerves to feelings ("a calculus of the nervous system"). She never achieved this, however. In part, her interest in the brain came from a long-running preoccupation, inherited from her mother, about her "potential" madness. As part of her research into this project, she visited the electrical engineer Andrew Crosse in 1844 to learn how to carry out electrical experiments. In the same year, she wrote a review of a paper by Baron Karl von Reichenbach, Researches on Magnetism, but this was not published and does not appear to have progressed past the first draft. In 1851, the year before her cancer struck, she wrote to her mother mentioning "certain productions" she was working on regarding the relation of maths and music.

In 1840, Babbage was invited to give a seminar at the University of Turin about his Analytical Engine. Luigi Menabrea, a young Italian engineer and the future Prime Minister of Italy, transcribed Babbage's lecture into French, and this transcript was subsequently published in the Bibliothèque universelle de Genève in October 1842. Babbage's friend Charles Wheatstone commissioned Lovelace to translate Menabrea's paper into English.

During a nine-month period in 1842–43, Lovelace translated Menabrea's article. She augmented the paper with seven notes, A to G, about three times longer than the translation. The translation and notes were then published in the September 1843 edition of Taylor's Scientific Memoirs under her initials AAL.

Explaining the Analytical Engine's function was a difficult task; many other scientists did not grasp the concept and the British establishment had shown little interest in it. Lovelace's notes even had to explain how the Analytical Engine differed from the original Difference Engine. Her work was well received at the time; the scientist Michael Faraday described himself as a supporter of her writing.

The notes are important in the early history of computers, especially since Note G described, in complete detail, a method for calculating a sequence of Bernoulli numbers using the Analytical Engine, which might have run correctly had it ever been built. Though Babbage's personal notes from 1837 to 1840 contain the first programs for the engine, the algorithm in Note G is often called the first published computer program. The engine was never completed and so the program was never tested.

In 1953, more than a century after her death, Ada Lovelace's notes on Babbage's Analytical Engine were republished as an appendix to B. V. Bowden's Faster than Thought: A Symposium on Digital Computing Machines. The engine has now been recognised as an early model for a computer and her notes as a description of a computer and software.

Controversy over contribution\\

Based on this work, Lovelace is often called the first computer programmer and her method has been called the world's first computer program.

\texttt{end Wikipedia}