Diff — Ada Lovelace

{{infobox

| title = Ada Lovelace

| image = ada-lovelace.jpg

| caption = Ada Lovelace, 1836 — watercolor portrait by Alfred Edward Chalon

| born = 10 December 1815, London, England

| died = 27 November 1852, London (aged 36)

| born_as = Augusta Ada Byron — daughter of Lord Byron

| known_for = The first published computer program, 1843

| program = [[Bernoulli numbers]] method for the [[Analytical Engine]]

| namesake = The **Ada** programming language (MIL-STD-1815)

| inspiration_for = [[AdaLogic BASIC]]

| called = "Enchantress of Numbers" — [[Charles Babbage]]

}}

**Ada Lovelace** — born **Augusta Ada Byron** (10 December 1815 – 27 November 1852), later Countess of Lovelace — was an English mathematician whose 1843 notes on the [[Analytical Engine]] contain what is often called the first published computer program, and the first clear statement of what programming could *mean*. She is the namesake of the **Ada** programming language and an inspiration for [[AdaLogic BASIC]].

## The poet's daughter, raised on mathematics

Ada was the only legitimate child of the poet **Lord Byron**, who left England weeks after her birth; she never knew him. Fearing poetry's contagion, her mother Annabella steered her toward mathematics and logic — a rigorous education rare for anyone, extraordinary for a woman of her era, with tutors including **Mary Somerville** and later **Augustus De Morgan**. Ada came to call her own style "**poetical science**": she refused to choose between imagination and rigor, and it shows in everything she wrote.

At twelve she designed a flying machine — studying birds' anatomy, writing a book of *Flyology* illustrated with her own diagrams, and concluding that steam power was the answer. The instinct to meet imagination with engineering never left her.

## The notes

Introduced to [[Charles Babbage]] at seventeen — she saw the Difference Engine demonstration and understood it immediately, "the gem of all mechanisms" — Ada followed the Analytical Engine for years through a long, lively correspondence with Babbage, who called her the "**Enchantress of Numbers**." When she translated Luigi Menabrea's French account of the machine in 1843, her added **notes A through G** tripled the paper's length — and **Note G** laid out a step-by-step method for the engine to compute [[Bernoulli numbers]]: the first algorithm published as intended for a machine.

[[File:bernoulli-diagram.jpg|right|340px|Lovelace's Note G table — the world's first published program, mapping each [[Bernoulli numbers|Bernoulli]] operation onto the engine's cards]]

The table itself is the remarkable artifact: columns listing the engine's operations, the variables each acts on, and the results — the direct ancestor of every source listing, trace, and state table since. It even contains one of history's first *bugs*: an index error she and Babbage later corrected by letter.

The notes reach further than code. She wrote that the engine "might act upon other things besides number" — that if objects' relations could be expressed symbolically, the machine might compose **"elaborate and scientific pieces of music."** Where others saw a calculator, Lovelace saw the computer as we now understand it. She was also the first to write down a bug risk plainly — her own Bernoulli table contains an error — and to insist a machine has no power to *originate* anything: the "**Lovelace objection**," still argued wherever machine intelligence is debated. [[Alan Turing]] engaged it directly a century later.

She died of uterine cancer at thirty-six, the same age as her father, and was buried beside him — the poet she never knew.

## Legacy

- The **Ada** language — commissioned by the US Department of Defense in 1980 for safety-critical systems — was named for her and assigned the reference **MIL-STD-1815**, her birth year.

- **Ada Lovelace Day** (second Tuesday of October) celebrates women in science and engineering.

- Whether she was "the first programmer" is debated — Babbage drafted earlier engine programs — but hers was the first *published*, the most sophisticated, and the only one wrapped in a vision of what such machines could become. [[AdaLogic BASIC]] honors the same inheritance: a language named in her spirit, built for clarity and real work.

## See also

- [[Charles Babbage]] · [[Analytical Engine]]

- [[Bernoulli numbers]]

- [[Jacquard Loom]] · [[Punched card]]

- [[Alan Turing]]

- [[AdaLogic BASIC]]

- [[History of Programming]]

[[Category:History]]

[[Category:People]]

- [[History of Science]]

[[Category:Programmers]]