Today's Google Doodle celebrates the birth of
Augusta Ada Byron, Countess of
Lovelace, more commonly known as Ada Lovelace, born 10 December 1815.
http://www.google.com.au/#q=Ada+Love...w=1264&bih=650
Ada Lovelace was the daughter of Lord Byron.
In 1842, mathematician Luigio Manabrea had written an article on
Charles Babbage's
design for the
Analytical Engine, an early proposed mechanical computer.
Ada Lovelace is best known for a set of notes she authored which supplemented
her translation of the article.
In these notes, which were longer than the translation of the article itself,
she recognized the significance of the Analytical Engine as being
a machine that could not only be used for arithmetic calculations but be used for general
symbolic manipulation that could represent, as she put it, "all subjects in the universe".
For example, she reasoned the machine could even be used to help "compose
elaborate and scientific pieces of music of any degree of complexity or extent".
In other words, she recognized that the Analytical Engine was what we think
of today as a generalized computer.
Babbage himself and his machines have an astronomical connection.
Babbage had gone to Cambridge University with his close friend,
John Herschel. Both had helped found the Astronomical Society (later the
Royal Astronomical Society). John, of course, was the son of none other
than William Herschel.
Whilst checking a set of tables that they had helped prepare for the Society, Baggage
proclaimed, "I wish to God these calculations had been executed by steam".
The two men then discussed this notion which gave rise to the idea for
Baggage's first calculating machine, the
Difference Engine.
The Difference Engine used mechanical gears to compute mathematical tables
using a powerful technique known as constant differences. It received backing
from the British Government as it was to be used to help produce more
reliable mathematical tables for nautical navigation. However, the levels of
engineering precision required to fabricate its parts challenged the technology
available at the time and a dispute with the machinist employed to build it,
Joseph Clement, led to cost overruns and delays that eventually resulted in it
never being finished.
Babbage was a talented mathematician and in fact held Newton's old chair of
Lucasian Professor of Mathematics at Cambridge. When work on the Difference
Engine stalled due to the dispute with the machinist Joseph Clement,
Babbage turned his mind to a more general purpose machine which
he called the Analytical Engine. This machine was to be programmable and
Ada Lovelace became fascinated by it when she first heard of it. She and
Babbage met on numerous occasions and began a correspondence discussing
it. In her notes on the Engine, she provided the details of how one might program
it to compute Bernoulli numbers.
As a result of this, some regard Ada Lovelace as the world's first computer
programmer.
The Analytical Engine was never completed. The Difference Engine eventually
made its way to the Science Museum in London where it is still on show today.
Postscript
The social circles in which Babbage and Lovelace moved included luminaries
such as Humphry Davies, Charles Darwin and Lord Wellington. The dinner parties
would have been fascinating to attend.
In the mid 1980's, I took the opportunity to visit the Science Museum specifically to
see the Difference Engine exhibit.
A programming language, called Ada, which was developed for the US Department
of Defense in the late 70's and early 80's, was named in honour of Ada Lovelace.
I briefly programmed in Ada whilst working as a computer systems research engineer
in the 80's, compiling and running code for a rare Intel CPU architecture known
as the iAPX-432. The Ada programming language is still used in many military
systems, such as the Patriot missile control system and the F-22 jet fighter
as well as the International Space Station guidance, navigation and control system.
Ada Lovelace - today's Google Doodle - Early astronomy computing connection
