Grace Hopper’s 108th Birthday
Source: Wikimedia Commons
She was buried in Arlington National Cemetery.
Babbage in the Science Museum
Photography by Carlos Dorce
My last post about the Science Museum is about Charles Babbage. We’ve seen that there is a difference machine in the groundfloor of the museum but in the mathematical section there is a special space dedicated to him and his machines:
Charles Babbage (1791-1871) is widely regarded as the first computer pioneer and the great ancestral figure in the history of computing. Babbage excelled in a variety of scientific and philosophical subjects though his present-day reputation rests largely on the invention and design of his vast mechanical calculating engines. His Analytical Engine conceived in 1834 is one of the startling intellectual feats of the nineteenth century. The design of this machine possesses all the essential logical features of the modern general purpose computer. However, there is no direct line of descent from Babbage’s work to the modern electronic computer invented by the pioneers of the electronic age in the late 1930s and early 1940s largely in ignorance of the detail of Babbage’s work.
Apart of his portrait from 1860, we can see in the exhibition the right sagittal section with cerebellum of his brain. Babbage’s son donated it for research to the Hunterian Museum at the Royal College of Surgeons in England. There also are extracts from his diary (1844):
Photography by Carlos Dorce
Charles Babbage invented the Difference Engine in 1821 but never built a full example. The only complete Difference Engine built during Babbage’s lifetime was made by Swedish engineers George and Edvard Scheutz. Inspired in Babbage’s ideas, and encouraged by Babbage himself, they printed the first ever mathematical tables calculated by machine. The Scheutz brothers went on to sell two further Difference Engines of which this is the second:
Photography by Carlos Dorce
Practical and finantial problems meant that Babbage and his engineer Joseph Clement completed only about a seventh of Babbage’s original mechanism, which is on display in the ‘Making the Modern World’ gallery on the ground floor. Known as Difference Engine No. 1, it is one of the finest examples of precision egineering from 19th-century England.
The world’s first mechanical computer was also invented by Babbage in 1834. He never saw his Analytical Machine finished and this small section was under construction when he died:
Photography by Carlos Dorce
There is also a model of the Difference Engine No. 2:
Photography by Carlos Dorce
Charles Babbage designed this mechanical calculating machine, called Difference Engine No. 2, between 1847 and 1849. He aimed to print mathematical tables that were much more accurate than the hand-produced versions available to Victorian engineers, scientists and navigators.
Babbage called his machine a Difference Engine because it calculated tables of sums automatically using ‘the method of finite differences’. This mathematical method involves only addition and subtraction, and avoids multiplication and division, which are more difficult to mechanise.
I have a picture in front of this machine with my students from our visit to the museum in February 2012:
Who took this picture for us?
Nowadays, the machine is part of this section dedicated exclusively to Babbage.
I am going to visit the Science Museum again next February and I am sure that another post will be written because there are a lot of pictures and things that I don’t have time now to share with you!
Location: Science Museum in London (map)
Babbage’s Difference Machine No. 1
Photography by Carlos Dorce
This is not going to be the only post dedicated to Babbage in the Science Museum. I’ve visited this museum in my birthday and I am going to write some posts about the mathematical section. However, the first thing that I saw after the exhibition about Turing is this Babbage’s Difference Machine No. 1.
This trial portion of the Difference Engine is one of the earliest automatic calculators and is a celebrated icon in the prehistory of the computer.
Charles Babbage was a brillant thinker and mathematician. He divised the Difference Engine to automate the production of error-free mathematical tables. In 1823 he secured 1500 pounds from the government and shortly afterwards he hired the engineer Joseph Clement.
The Difference Engine was designed to perform fixed operations automatically. During its development Babbage’s mind leapt forward to the design of the Analytical Engine, which using punched cards could be programmed to calculate almost any function. This design embodied almost all the conceptual elements of the modern electronic computer.
The project collapsed in 1833 when Clement downed tools. By then, the government had spent over 17.000 pounds to build the machine -equivalent to the price of two warships. The collapse of the venture was traumatic for Babbage and, in old age, he became embittered and disillusioned.
Historians have suggested that the design was beyond the capability of contemporany technology and would have required greater accuracy than contemporany engineering could have provided. However, recent research has shown that Clement’s work was adequate to create a functioning machine. In fact, the scheme founderer on issues of economics, politics, Babbage’s temperament and his style of directing the enterprise.
Location: Science Museum in London (map)
Turing in the Science Museum
Photography by Carlos Dorce
Today is my birthday and I’m in London! My wife, my son, my daughter and me have decided to go to the Science Museum and we have found an interesting exhibition about Alan Turing:
The Second World War was not just fought with bombs and shells. It was a war of electronic whispers and secret radio signals snatched from the ether.
At Bletchey Park, Buckinghamshire, thousands of men and women laboured night and day to crack these coded radio messages which held Germany’s most secret plans. One of these codebreakers was Alan Turing.
But Turing was not just a codebreaker. Born 100 years ago, the British mathematician was also a philosopher and computing pioneer who grappled with some of the fundamental problems of life itself. Yet his own life was cut tragically short. In 1954 he was found dead, poisoned by cyanide. He was 41.
Throughout his life, Turing broke the codes of science and society. His ideas helped shape the modern world – but it was a world he did not live to see. This is his story.
After the Second World War, Alan Turing as asked to put his theories and experience into action by developing a ground-breaking electronic computer at the government’s National Physical Laboratory. His first specifications were written in 1945.
Following administrative delays, Turing left the project in 1948, but a trial version (known as Pilot ACE) was completed in 1950. It is now the most significant artefact in existence.
Yet the Pilot ACE computer was more than just a trial. It was used for several years by a variety of external customers desperate to employ its computing power. It also became a public celebrity, referred to as Turing’s ‘electronic brain’.
(Very bad) Photography by Carlos Dorce
So Turing was the man who broke Enigma and this machine is also shown in the exhibition:
Photography by Carlos Dorce
Enigma machines were first introduced in the 1920s for keeping commercial messages secret. An Enigma machine was used at both the transmitting and the receiving end of the message.
Senders typed their messages on the keyboard. Each typed letter was encrypted by passing an electrical signal through a plug-board and rotors, causing a different letter to light up. These new letters formed a secure message, ehich could be transmitted by radio to the recipient.
At the receiving end, the message was decrypted using an Enigma machine that had been set up initially in exactly the same way as the sending machine.
Soon after their introduction, government institutions and the military began to use modified Enigma machines for their secret communications, believing nobody would be able to break the cipher system. But this was what Alan Turing and his colleagues managed to do.
Alan Turing worked at Bletchey and he developed sophisticated decryption processes and devised the machines called ‘bombes’ that could break the code on an industrial scale. Some 200 bombes were built at a secret facility nearby. The exhibition had some pictures about the bombs and these two wheels from a bomb machine, c. 1940:
Photography by Carlos Dorce
Next to Turing’s bombs and computers we can also see these two pioneer calculating machines:
Photography by Carlos Dorce
The right one is a mechanical logic machine by William Stanley Jevons (1869) and the other is an electrical logic machine by Dietrich Pronz and Wolfe Mays (1949).
We have some personal aspects of this important man too. For example, the exhibition points to the fact that in 1927 Turing began a close friendship with a boy at this school, Christopher Morcom. In 1930 Morcom died from tuberculosis, aged 18, and Turing wrote a short essay expressing his belief that the human spirit can live outside the body.
Photography by Carlos Dorce
The exhibition also shows this calculating machine used at the Scientific Computer Service in 1939:
Photography by Carlos Dorce
I didn’t know that questions like…
What will be the position of the Moon in A.D.2000? How would you know the right direction in which to point an anti-aircraft gun?
were posed in a 1942 newspaper articleabout the Scientific Computing Service. Before Turing’s computer, ‘computers’ were human and usually women. In fact, in 1936 Turing wrote an article which was the theoretical basis for today’s computers because he imagined a machine that could compute any problem.
In 1948, Alan Turing moved to Manchester University to work on a ground-breaking stored-program computer developing mathematical theories of morphogenesis (growth and patterns in animals and plants). In those years he began a relationship with Arnold Murray and in 1952 Turing was arrested under anti-homosexuality legislation. Given a choice of imprisonment or a one-year course of female hormones, he opted for the latter. It seems that he couldn’t stand that kind of experiment and he committed suicide.
Photography by Carlos Dorce
Location: Science Museum in London (map)
THE MATHEMATICAL TOURIST 