Respect For The Masters: Ada Lovelace




Augusta Ada King, Countess of Lovelace (10 December 1815 – 27 November 1852), born Augusta Ada Byron and now commonly known as Ada Lovelace, was an English mathematician and writer chiefly known for her work on Charles Babbage's early mechanical general-purpose computer, the Analytical Engine. Her notes on the engine include what is recognised as the first algorithm intended to be processed by a machine. Because of this, she is often considered the world's first computer programmer.

First computer program
 
In 1842 Charles Babbage was invited to give a seminar at the University of Turin about his analytical engine. Luigi Menabrea, a young Italian engineer, and future Prime Minister of Italy, wrote up Babbage's lecture in French, and this transcript was subsequently published in the Bibliothèque universelle de Genève in October 1842.
Babbage asked Ada to translate Menabrea's paper into English, subsequently requesting that she augment the notes she had added to the translation. Ada spent most of a year doing this. These notes, which are more extensive than Menabrea's paper, were then published in The Ladies' Diary and Taylor's Scientific Memoirs under the initialism "AAL".
In 1953, over one hundred years after her death, Ada's notes on Babbage's Analytical Engine were republished. The engine has now been recognised as an early model for a computer and Ada's notes as a description of a computer and software.
Ada's notes were labelled alphabetically from A to G. In note G, she describes an algorithm for the analytical engine to compute Bernoulli numbers. It is considered the first algorithm ever specifically tailored for implementation on a computer, and for this reason Ada is often cited as the first computer programmer; however, the engine was not completed during Lovelace's lifetime.

Conceptual leap

In her notes, Lovelace emphasized the difference between the Analytical Engine and previous calculating machines, particularly its ability to be programmed to solve problems of any complexity. Lovelace realised that the potential of the device extended far beyond mere number crunching. She wrote:
[The Analytical Engine] might act upon other things besides number, were objects found whose mutual fundamental relations could be expressed by those of the abstract science of operations, and which should be also susceptible of adaptations to the action of the operating notation and mechanism of the engine...
Supposing, for instance, that the fundamental relations of pitched sounds in the science of harmony and of musical composition were susceptible of such expression and adaptations, the engine might compose elaborate and scientific pieces of music of any degree of complexity or extent.
This analysis was a conceptual leap from previous ideas about the capabilities of computing devices, and foreshadowed the capabilities and implications of the modern computer. This insight is seen as significant by writers such as Betty Toole and Benjamin Woolley, as well as programmer John Graham-Cumming, whose project Plan 28 has the aim of constructing the first complete Analytical Engine.

Controversy over extent of contributions

Though Ada Lovelace is often referred to as the first computer programmer, there is disagreement over the extent of her contributions, and whether she deserves to be called a programmer. Allan G. Bromley, in the 1990 essay "Difference and Analytical Engines", wrote, "All but one of the programs cited in her notes had been prepared by Babbage from three to seven years earlier. The exception was prepared by Babbage for her, although she did detect a "bug" in it. Not only is there no evidence that Ada ever prepared a program for the Analytical Engine but her correspondence with Babbage shows that she did not have the knowledge to do so." Curator and author Doron Swade, in his 2001 book The Difference Engine, wrote, "The first algorithms or stepwise operations leading to a solution – what we would now recognise as a 'program', though the word was not used by her or by Babbage – were certainly published under her name. But the work had been completed by Babbage much earlier."
 
Historian Bruce Collier went further in his 1990 book The Little Engine That Could've, calling Ada not only irrelevant, but delusional:
It would be only a slight exaggeration to say that Babbage wrote the 'Notes' to Menabrea's paper, but for reasons of his own encouraged the illusion in the minds of Ada and the public that they were authored by her. It is no exaggeration to say that she was a manic depressive with the most amazing delusions about her own talents, and a rather shallow understanding of both Charles Babbage and the Analytical Engine... To me, [correspondence between Ada and Babbage] seems to make obvious once again that Ada was as mad as a hatter, and contributed little more to the 'Notes' than trouble.
Writer Benjamin Woolley would say that while Ada's mathematical abilities have been contested, she can claim "some contribution": "Note A, the first she wrote and the one over which Babbage had the least influence, contains a sophisticated analysis of the idea and implications of mechanical computation." And that this discussion of the implications of Babbage's invention was the most important aspect of her work. According to Woolley, her notes were "detailed and thorough [a]nd still... metaphysical, meaningfully so"; they were able to explain how the machine worked and "[rose] above the technical minutiae of Babbage's extraordinary invention to reveal its true grandeur."
Babbage published the following on Ada's contribution, in his Passages from the Life of a Philosopher (1864):
I then suggested that she add some notes to Menabrea's memoir, an idea which was immediately adopted. We discussed together the various illustrations that might be introduced: I suggested several but the selection was entirely her own. So also was the algebraic working out of the different problems, except, indeed, that relating to the numbers of Bernoulli, which I had offered to do to save Lady Lovelace the trouble. This she sent back to me for an amendment, having detected a grave mistake which I had made in the process.
The "algebraic working out" Babbage describes is the derivation of the mathematical equations 1 through 9 in Note G, not the Table & Diagram in Note G showing punch card flow. The table, not the equations, is considered the first computer program. In Ada's and Babbage's letters to each other in 1843, the only contemporary documentation, Ada mentions finding and correcting errors in "our first edition of a Table & Diagram" (Ada frequently used "our" when discussing the Notes in letters with Babbage).

Source:
http://en.wikipedia.org/wiki/Ada_Lovelace

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