The Department of Electrical & Electronic Engineering hosts an annual lecture event directed to topics of wide interest and importance to engineers and the community. The new lecture series commemorates Alec Reeves, an alumnus of Imperial College London.
Reeves is widely regarded as ‘the father of the digital age’ in that he was the inventor of Pulse Code Modulation, one of the platforms which underpins today’s pervasive digital technology, and also undertook important work on radar and radio navigation in wartime Britain. Read more about Alec Reeves below.
The 2006 Alec Reeves Lectures, will be given by David Robertson and Tony Sale. David, a well known communicator on science and technology, will be talking about the life and work of Reeves himself. Tony has long been associated with the historical and technical aspects of the vital wartime code-breaking activities, mainly undertaken at Bletchley Park, and will be talking about the events leading up to the re-build of the Colossus computer.
14.30 Alec Reeves: designer of the digital age – David Robertson – Room 408 –
from 15.30 Strategic Advisory Group – Poster Presentations will be held in Room 509
17.30 The Lorenz cipher – Fish, Tunny and Colossus – Tony Sale – Room 408.
Alec Reeves: The Reeves Lectures celebrate the life and work of an Imperial College graduate who was one of the world’s greatest – but least conventional – scientists and engineers. Born a year after the death of Queen Victoria, he devised the technology on which our ‘information age’ depends. A committed pacifist, he developed a navigation system that altered the course – and perhaps the outcome – of WWII. A prolific and practical inventor, he routinely experimented with the paranormal.
Alec Harley Reeves was born on 2nd March 1902 at Redhill, Surrey. He went to Reigate Grammar School and in 1918 won a Governors’ Scholarship to the City and Guilds Engineering College – later part of Imperial College. He received its ACGI (equivalent to a BSc) in 1921 and then came to Imperial to do postgraduate research. As well as important theoretical work on radio, he invented a cathode ray tube radio direction finder.
In 1923, Reeves joined the communications firm International Western Electric. Working initially at New Southgate, North London, with the distinguished French engineer Maurice Deloraine, he helped create the first high-frequency radio telephone link across the Atlantic.
When in 1925 IWE was taken over by International Telephone and Telegraph, Reeves moved to its Paris laboratory where, in 1937, he made his greatest contribution to engineering history. Pulse Code Modulation made possible the digital transmission of speech and our modern multimedia age. Though PCM was not used commercially until the later invention of the transistor, Bell Labs applied it for the complex and cumbersome radio system on which Churchill and Roosevelt talked in total secrecy for much of WWII.
The Germans invaded France in 1940 and Alec Reeves escaped to Spain – reaching England on a coal boat without his possessions. Initially reluctant to do war work, he saw the moral necessity of defeating Hitler and joined the Royal Aircraft Establishment at Farnborough. Under the powerful Head of Scientific Intelligence, R V Jones, he played a key role in the ‘battle of the beams’ – helping detect and destroy the radio navigation systems with which the Nazis inflicted deadly damage on cities like London and Coventry.
Britain’s counter-attack was initially hampered by poor navigation and Reeves now joined the Telecommunications Research Establishment (TRE) to help our bombers find and hit their target. His solution was Oboe – the most accurate navigational device until the age of the satellite.
After WWII, Reeves returned to ITT’s UK laboratory STL where he sought ways to increase the capacity and reliability of communications systems, helped develop early electronic switching systems and was a pioneer of semiconductor devices – including the ‘positive gap’ germanium diode. He was also among the first to appreciate the potential of light as a carrier, inspiring the STL team under Charles Kao and George Hockham that invented optical fibres.
Reeves spent his final years as a freelance ‘boffin’ – spotting trends or proposing avenues of research for younger engineers to investigate. He was also a ‘father figure’ in communications and electronics – predicting universal mobile telephony, portable phone numbers, satellite navigation and the Internet. And he saw how communications could change lifestyles, noting that ‘the transport of intelligence and information is … much more sensible than the much slower and more expensive moving about of human bodies’.
Alec Reeves died of bowel cancer on 13 October 1971. He had received most – if perhaps not all – of the honours he could have expected as a major scientist and inventor: an OBE and a CBE; the top medal from America’s Franklin Institute; awards from professional bodies like the IEE; honorary degrees – and a stamp in recognition of PCM.
If Alec Reeves is less well known than contemporaries of similar stature such as Claude Shannon and Alan Turing, this may reflect his unconventional methods. Many creative people believe ideas are ‘out there’, waiting to be grasped. Reeves took the phrase literally, sharing with his father – the distinguished geographer Edward Reeves – a lifelong interest in the paranormal. Like Thomas Edison, Oliver Lodge and John Logie Baird, he thought he could communicate with the dead. He even claimed his work was ‘guided’ by the great 19th century experimentalist Michael Faraday.
Alec Reeves: designer of the digital age, David Robertson
Abstract : In 1937, a British electrical engineer solved a problem – and laid the foundations for the modern world. The engineer was Alec Reeves who was working at the Paris laboratories of the American multinational ITT. The ‘problem’ was how to reduce noise on long-distance radio telephone circuits. Since Alexander Graham Bell had invented the telephone in 1876 , speech and music were sent by what he called a ‘voice shaped current’ – one that varied continuously in line with the original sound. It worked well but had a key weakness. Radio and cable systems – especially long ones – needed amplifiers to boost the signal at intermediate points. But when you amplified the signal, you automatically boosted the snap crackle and pop.
Reeves’ answer was as simple as it was radical. Instead of sending an ‘analogue’ or copy of the original sound, he proposed it be sampled at regular intervals. The values of the samples would be turned into numbers and these numbers transmitted as streams of unequivocal on-off pulses. His technique, was called Pulse Code Modulation. It eliminated unwanted noise and is the basis of all modern telecoms networks. But there is much more to Reeves’ legacy, for without PCM we’d have no CDs, DVDs or CD-ROMS; no digital radio and television; no digital landline or mobile telephony; no broadband networks; no email, e-commerce or World Wide Web.
In World War 2, Reeves faced another challenge: how to ensure pilots could find their targets, especially at night and in poor weather. His answer? A ‘blind bombing’ system called Oboe so accurate that a bomb dropped from 30,000 feet could land within 50 yards of its target.
Later Reeves inspired the invention of that other key ingredient of our ‘information age’ – optical fibres that transmit huge volumes of information over tiny threads of glass. Alec Reeves is virtually unknown to the public at large. One reason may be the way he got his ideas. He was passionately involved with spiritualism and believed he was inspired by daily ‘dialogue’ with great scientists from the past such as Michael Faraday.
These and other aspects of the life of a rare and controversial genius will be explored by David Robertson in ‘Alec Reev es: Designer of the digital age’
Biography: David Robertson is a communications professional specialising in science and technology. He wrote for The Scotsman, worked in international student politics and was then Head of Publicity for The Industrial Society where he handled external PR and lectured in employee communications.
In 1975, David joined the IT firm STC. He directed a major programme to mark its centenary including the 1982/83 IEE Faraday Lecture The Photon Connection and the Science Museum’s Telecommunications gallery. With Dr Jonathan Miller, he wrote the film Echoes (which explores the impact of communications on society) for continuous showing in the museum.
In 1985 David created Technology Response, a consultancy that devises creative communications projects in science and engineering. He ran a two-year programme for the DTI to persuade computer suppliers to pay more attention to the needs of human users; he was Communications Director of the Technical Change Centre – an independent body advising government and industry on the adoption and impact of new technology; and he led a study into the content and design of an IT-based visitor attraction in the Thames Valley.
David directed the 1994/95 IEE Faraday Lecture Making Waves for Cellnet and Motorola and set up a programme of high-tech displays in museums and science centres for the Met Office. In 2000, he devised The Magic Ear – a touring exhibition on the history of radar – and in 2002 he wrote and produced Birth of the Smart Bomber, a 50-minute film in Channel 4’s Secrets of the Dead series about Oboe, the top-secret WW2 blind bombing system devised by Alec Reeves – the eccentric genius whose invention of pulse code modulation laid the foundations of our digital age. In 2003, he presented Future Labs – a three-part series for BBC Radio 4 describing some of the world’s great research laboratories and lectured at the National Museum of Scotland on Who invented the Telephone?
In 2004, David completed an exhibition at the Heathrow Airport Visitor Centre about the link between weather and aviation and delivered paper to the IEE on Alec Reeves and in 2005 he moved The Magic Ear to the Transmitter Block at Bawdsey Manor in Suffolk – the world’s first operational radar station. He is now managing Shout and Whisper, an oral history project for Bawdsey Radar Group sponsored by the Heritage Lottery Fund. He will be producing an educational pack, DVD, booklet and other resources. He is also completing a biography of Alec Reeves and writing an article for the Dictionary of National Biography about John Bray, BT’s former Director of Research.
The Lorenz cipher: Fish, Tunny and Colossus – Tony Sale
In 1940, a listening unit of the British Police – assigned to monitor the activity of German agents – intercepted a new type of non-Morse transmission. The German Army High Command had asked the Lorenz company to produce a high security teleprinter cipher machine to enable them to communicate by radio in complete secrecy. This cipher machine was based on an additive enciphering technique for teleprinter messages invented by Gilbert Vernam. The code breaking centre, Bletchley Park (also known as Station X), gave the codename ‘Fish’ to the teleprinter traffic and the codename ‘Tunny’ to the material enciphered by the Lorenz machine.
The first real break into Tunny traffic occurred on August 30, 1941 when a cipher clerk in Vienna sent a long message – four thousand or so characters – to his opposite number in Athens. When he had finished this formidable typing effort he received a reply which was the German equivalent of ‘I didn’t get all that. Please send it again..!’. So he did – using, against all established principles of cipher security, the same machine settings that he had used for the first transmission. He also used a number of abbreviations [e.g. ‘Spruchnummer’ became ‘Spruchnr’ , etc.]. This egregious error was the chance for which Bletchley Park was waiting and a team headed by Colonel John Tiltman deciphered the message in short order.
Tiltman passed the material to a young Cambridge mathematician, Bill Tutte, who immediately set to work in a attempt to determine the principle by which the Lorenz machine worked. Only four months later, Tutte and Bletchley Park had a working knowledge of the internals of the device and were able to build an electro-mechanical analogue – the Tunny machine. The mathematician Max Newman thought that it would be possible to automate some parts of the deciphering process. He approached TRE at Malvern and asked them to design an electronic machine to implement Bill Tutte’s algorithm. The machine was built at Dollis Hill and was known as Heath Robinson after the cartoonist designer of fantastic machines. There were problems with Heath Robinson, but it worked well enough to show that Max Newman’s concept was correct. Newman then went to Dollis Hill where he was put in touch with Tommy Flowers, the brilliant Post Office electronics engineer. Flowers went on to design and build Colossus to meet Max Newman’s requirements for a machine to speed up the breaking of the Lorenz cipher.
Tony Sale will tell the story surrounding Colossus and its recent re-build.
Biography: Tony Sale has had careers in the Royal Air Force, the Marconi Research Laboratories and MI 5. He ran his own computer software company for 12 years, has been Technical Director of the British Computer Society and managed the Computer Restoration Project at the Science Museum in London. In 1991, he joined the campaign to save Bletchley Park from housing development. In 1992 he was Secre t ary to the newly formed Bletchley Park Trust, later a Trustee and Museums Director until 1999. In 1993 he started the Colossus Rebuild Project to rebuild the Colossus computer developed at Dollis Hill in 1943 for Bletchley Park. As a result of his Colossus rebuild work, he was awarded the Comdex IT Personality of the Year for 1998. He also received the 2000 Royal Society of Scotland Silver Medal. Soon after becoming interested in computers, he joined the British Computer Society (BCS) in 1965 as Associate Member, being elected to Member in 1967, Fellow in 1988 and Hon. Fellow in 1996. He was elected to the Council of the BCS for the period 1967-70. In 1965 was a founder member of the Bedfordshire Branch of the BCS and was chairman in 1979. Tony Sale has appeared on television all over the world and has lectured widely on wartime code breaking in the UK, Europe and the USA . He was Technical Advisor to Mick Jagger’s 2001 film ‘Enigma’.
His web site, www.codesandciphers.org.uk is recognised as a major source of information on all aspects of World War II code breaking. His booklet ‘Colossus 1943 – 1996’ describes the breaking of the German Lorenz cipher and his rebuild of the Colossus computer.The Alec Reeves Lecture is funded by the Andre Gabor bequest in memory of Professor Dennis Gabor CBE, a former member of the Department of Electrical and Electronic Engineering who was awarded the Nobel Prize for Physics in 1971.