CPSC 101 Bonus Lecture Historical Perspective Ciarán Llachlan Leavitt and Vania Chan February 13, 2007

Course Calendar CPSC 101 (4) Connecting with Computer Science Fundamentals of computer science and their connections with the arts, psychology, and biology. Historical, cultural, and gender perspectives of important contributions to the field will be discussed. No prior computing background required. [3-3-0] Equivalency: WMST 201.

Agenda  Charles Babbage, The Father of Computing  Ada, Countess of Lovelace, The First Computer Programmer  What is missing from the Babbage and Lovelace story? How is history being rewritten?  Other algorithmic thinkers throughout history

Charles Babbage  1791 – 1871  Mathematician  Cambridge professor  Inventor  Difference engine  Analytical engine  Many others….  Industrialist  Philosopher  Politician  Charismatic, colourful, crotchety

Before calculations were automated….  Scientists, navigators, engineers, surveyors, relied on printed mathematical tables  Tables were prone to error  errors of calculation (humans performed the routine calculations)  errors of transcription (copying into a suitable format for the printer )  errors of typesetting and printing

Difference Engine  A calculating machine  Calculate without error  Print without error  Based on the method of finite differences  Never completed  Tools to make the parts were crude, 1820s  Arguments with engineers  Funding issues  London Science Museum, 1991  Built it! It worked!  7 numbers of 31 decimal digits each  Tabulate 7th degree polynomials to that precision

Analytical Engine  1830s-1870s, Babbage envisioned a universal machine for finding the value of almost any algebraic function  Included logical features of a modern computer  programmable using punched cards.  a ‘store’ to hold numbers and intermediate results  a separate ‘mill’ to perform arithmetic processing  Capable of loops and conditional statements (IF…THEN…)  But never built  Would have been powered by steam engine  Babbage = Father of Computing

Ada, Countess of Lovelace  1815 – 1852  Lady Augusta Ada Byron,  Right Honourable Ada King  Countess of Lovelace  Poet and mathematician  First computer programmer

Lovelace’s Contributions: A Typical Description  During a nine-month period in , Ada translated Italian mathematician Luigi Menabrea's memoir on Babbage's newest proposed machine, the Analytical Engine. With the article, she appended a set of notes which specified in complete detail a method for calculating Bernoulli numbers with the Engine, recognized by historians as the world's first computer program. Ada was also the mother of three children. (Excerpt from Wikipedia)

Controversy  A question of class  A question of means  A question of gender  A question of time  A question of credit

A Revised Description  Babbage worked on plans for this new engine and reported on the developments at a seminar in Turin, Italy in the autumn of An Italian, Menabrea, wrote a summary of what Babbage described and published an article in French about the development. Ada, in 1843, married to the Earl of Lovelace and the mother of three children under the age of eight, translated Menabrea's article. When she showed Babbage her translation he suggested that she add her own notes, which turned out to be three times the length of the original article. Letters between Babbage and Ada flew back and forth filled with fact and fantasy. In her article, published in 1843, Lady Lovelace's prescient comments included her predictions that such a machine might be used to compose complex music, to produce graphics, and would be used for both practical and scientific use. She was correct. (Excerpt from The Ada Project)

References  A biography of Charles Babbage  The Ada Project  British Science Museum  Wikipedia