Legends

Ada Lovelace, the 19th century genius who conceptualised the modern computer

30 December 2020, 7:35pm

Today Ada Lovelace is recognised as one of the foremost thinkers of the Victorian Age. While her contemporary Michael Faraday regarded her as “the rising star of Science,” and her inspired exposition of Charles Babbage’s pioneering mechanical works presaged the Computer Age, her fame was short-lived, and her name eclipsed until the computer revolution of the 20th century. A luminary of her day, with ideas before her time, Ada’s influence might have been immeasurable were it not for her premature death.

Painting of Ada Lovelace by Margaret Carpenter, 1836

In 1815, Augusta Ada Byron was born in Leicestershire in England to two exceptional parents. She was the only legitimate child of Lord Byron, a politician, revolutionary, and one of Britain’s greatest poets, and his wife, Annabella Milbanke, a mathematician, abolitionist, and philanthropist. The “mad, bad and dangerous to know” Lord Byron and his modest, prim, and pragmatic “princess of parallelograms” were an unlikely match and separated a month after Ada’s birth. Four months later, amid scandalous rumours of infidelities – and even incest with his half-sister, Augusta Leigh, after whom Ada was named – Byron fled the country, never to return.

Unusually for the time, Annabella took custody of her daughter. She steered Ada quite deliberately into logical pursuits, hoping to counteract any “Romantic excess” or perceived insanity she may have inherited from her father. By the age of eight, when Byron died from a fever contracted during Greece’s War of Independence against the Ottomans, Ada was already fascinated by machines, exhibiting a precocious mechanical ingenuity. Highly educated herself, Annabella insisted on a rigorous curriculum of logic, science, and mathematics for Ada. One in a succession of her many tutors was Mary Somerville, the Scottish scientist, mathematician, and polymath, who belonged to the same intellectual milieu of moneyed and talented women as her mother.

Somerville, after whom the eponymous ladies’ college at Oxford was named posthumously, became a life-long friend and mentor to Ada. It was through Somerville, the Victorian “queen of science”, that Ada met the mathematician, mechanical engineer, and inventor Charles Babbage, at one of his famous Saturday gatherings of London’s intellectual elite. Fascinated by a working prototype of Babbage’s Difference Engine, Ada’s interest in mathematics was ignited, and a close working relationship that was to last twenty years was forged between the 41-year-old gentleman of science and the gifted 17-year-old debutante. Babbage went on to call her “The Enchantress of Numbers”.

For more than a decade, Babbage had aspired to make mathematical tables by machine, claiming that “computations of great complexity can be made by mechanical means”. Mechanical calculators had existed in antiquity, and Pascal had built one in 1642, but in Babbage’s day “human computers” were still relied upon to draw up logarithmic tables, and so computations were subject to human error. Though lacking a printer, Babbage’s Difference Engine was a fixed-function calculator that negated human fallibility. It could compute polynomials by method of differences, and automatically step through values to the correct result. After a decade, however, due in part to funding difficulties but more to lack of focus, Babbage’s Difference Engine remained unfinished.

Just a few days after their first encounter, Babbage invited Ada to inspect a different set of blueprints. Babbage had devised a new multi-purpose computational machine: a first of its kind calculator that was programmable by punched cards adapted from the kind invented in 1801 by Jacquard for weaving elaborate patterns on automated looms. Ada was captivated at once by the idea, and its myriad possible applications. When a lecture that Babbage had given on this Analytical Engine was written up and published in French it was Ada whom Babbage tasked to translate it. Ada worked feverishly for some nine months, not only translating, but appending her own corrections, clarifications, and elaborations, expanding the original from eight to twenty-thousand words. It is these seminal notes that are the source of Ada Lovelace’s enduring fame.

Though the Analytical Engine and its construction were all Babbage’s own work, Ada alone was able to envisage and explain what the mathematics involved could achieve. In the 1600s, Leibnitz had conceptualised something like universal computation and, in his long pursuit of a machine that could produce mathematical tables, Babbage had hit upon a machine capable of it. Babbage had already made an extraordinarily huge leap by originating the concept for the first automated digital computer with his Difference Engine. His newest invention embodied almost every significant feature of the modern digital computer, but it was Ada who recognised its full potential. Ada believed “the science of operations, as derived from mathematics more especially, is a science of itself, and has its own abstract truth and value,” anticipating the as yet distinct field of computing, or as she called it the “science of operations.” Including as they did a method for calculating a sequence of Bernoulli numbers, her notes are also credited with having contained what is considered the first computer program in history, known as Note G.

Not until long after Ada’s death were her contributions to the field of computing acknowledged fully. Her notes inspired Turing’s work on the first modern computers a hundred years later during World War II. She was the first to recognise that machines such as the Analytical Engine had applications beyond pure calculation, essentially conceptualising the modern computer. Imagining the applications that complex automated algorithms might have, she understood what a computer might really be. For this vision she is often considered the ‘Prophet of the Computer Age.’ What can only be guessed at is what she might have achieved had she not died at 36 from cancer. With Ada’s premature death the Analytical Engine was never finished, and it took until the twentieth century for Ada’s ideas to be realised. Today Ada Lovelace is a symbol for modern women in technology, and International Ada Lovelace Day celebrates the achievements of women in science, technology, engineering, and mathematics.