Sir Robert Watson-Watt, physicist and inventor of radar, died on the 5th of December, 1973.
Robert Watson Watt had inventing in his blood as he was a direct descendant of the inventor James Watt. Instead of sitting around getting all steamed up, Watt got all wired up in radio waves and became more concerned with valves that amplified electronic signals rather than valves that controlled the emission of steam. It was due to Watt’s invention of ‘radio detecting and ranging’ – otherwise known as radar – that the blue-eyed German Luftwaffe pilots were left scratching their crew-cut blond hair struggling to understand why Britain’s Spitfires and Hurricanes were always in the air to meet them over the Channel during the Battle of Britain. Churchill’s “few” were able to be in the right place at the right time, because Watt’s radar stations were able to detect ‘Jerry’ at up to seventy miles away. Watt probably added the hyphen to his name, because everyone thought he already had two surnames anyway and so it was that he became Sir Watson-Watt in 1942. He looked every inch the boffin and in truth, he was a bit pompou; if he could use five words instead of one, he would. After the ‘War’ he was reportedly disappointed that he did not gain more recognition for his contribution to the Allies’ victory, but in 1952, he was ‘rewarded’ for his contribution to saving Britons from having to learn German. The British Government gave him £50,000 and the Yanks gave him the US Medal of Merit.
Of course, the basic principles of radio wave reflection and electromagnetic waves had been established already, by another famous Scot; James Clerk Maxwell. Ironically, however, it was a German, Heinrich Hertz, who was the first to demonstrate experimentally the production and detection of Maxwell’s waves. That discovery led directly to radio and ultimately, radar. Hertz’ name lives on as the unit of frequency of a radio wave – one oscillation or cycle per second is one Hertz (Hz), which at radio frequencies, is usually represented in megahertz (MHz). Coincidently, another yet German speaker is associated with radar. Christian Andreas Doppler was an Austrian who first described, way back in 1842, the phenomenon that has since become known as the ‘Doppler Effect’. That principle is very important for the range finding aspect of radar systems and you can see how it works by standing in front of an approaching train.
Don’t take that literally, but think of the sound wave of a passing train. The sound of the train becomes ‘higher’ in pitch as it draws nearer and ‘lower’ in pitch as it passes and draws further away. The train makes a constant noise, but the number of sound waves reaching your ear in a given amount of time is what determines the tone, or pitch, you perceive. As the train gets closer, the number of sound waves reaching your ear increases, therefore, the pitch increases and as the train moves away, it decreases. It gives the false effect of accelerating closer and decelerating away as the observed frequency is affected by the relative motion of you (stationary in this example) and the moving train.
Watson-Watt was responsible for creating the first workable radar system, turning theory into one of the most important ‘weapons’ of the War, however, his invention also had the obvious civil applications. Radar was patented in 1935 and Watson-Watt went on to develop airborne intercept radar, which helps fighter planes detect enemy aircraft in the dark. Amongst his other contributions can be listed a cathode-ray direction finder, which was used to study atmospheric phenomena; his research in electromagnetic radiation, and other inventions used for flight safety. In 1926, he also gave us the phrase ‘ionosphere’, which is the uppermost part of the atmosphere where it becomes ionised by solar radiation.
Robert Alexander Watson Watt was born in Brechin on the 13th of April, 1892. He was educated at Damacre School in Brechin and at Brechin High School, before gaining a bursary to study at St Andrews, which he took up to study electrical engineering at University College in Dundee, which was then an off-shoot of St Andrews University. He graduated with a BSc(Engineering) in 1912 and became an assistant to Professor William Peddie, who encouraged Watt’s interest in radio waves. Later, in 1915, Watson Watt began work as a meteorologist at the Royal Aircraft Factory at Farnborough with the aim of applying his knowledge of radio to the early detection of thunderstorms. Lightning gives off a radio signal as it ionizes the air and Watt planned on detecting that in order to warn aviators of approaching storms. He found that aircraft could also be detected without being seen, thereby paving the way for his system that tied together the technological elements necessary to create an effective radar network that worked in the real world.
In 1924, Watson-Watt moved to the Radio Research Station at Slough and in 1933, after a couple of amalgamations, he became Superintendent of a new Department Of Radio Research at the National Physics Laboratory in Teddington. One of the first things he did was to prove to the Air Ministry that Nazi Germany’s claims of having a ‘death ray’ were merely noise. Later, Watson-Watt and his assistant Arnold Wilkins drafted a report entitled ‘The Detection of Aircraft by Radio Methods’, which was presented to the Committee for the Scientific Survey of Air Defence. On the 26th of February, 1935, a successful trial took place using the BBC’s short-wave transmitter at Daventry against a Heyford Bomber. Watson-Watt became Superintendent of Bawdsey Research Station, near Felixstowe, on the 1st of September, 1936, and persuaded the government to set up a network of early warning radar stations. The initial system, known as ‘Chain Home’ and ‘Chain Home Low’, was erected in time for the outbreak of the Second World War in 1939. Eventually, a chain of two hundred and fifty huge masts were erected at strategic points along the coastline, from Southampton to Scapa Flow.
Sir Robert Alexander Watson-Watt spent much of the latter part of his life in Canada and the USA, but he died in Inverness, on the 5th of December, 1973, and he was buried in the Kirkyard at Pitlochry.