Gday...

1770  -     Lieutenant James Cook discovers and names Queenland's Glass House Mountains. 

1902  -     Archaeologist Spyridon Stais discovers the Antikythera mechanism, believed to be an early clockwork mechanism from circa 87 BC. 

Spyridon Stais was a leading archaeologist working a shipwreck that had been discovered at a depth of about 40 metres off the Greek island of Antikythera in 1900. On 17 May 1902, divers retrieving staues and other items from the wreck brought up a piece of rock which had a gear wheel embedded in it. The item, which has become known as the Antikythera mechanism, is one of the oldest surviving geared mechanisms, made from bronze in a wooden frame.

Since its discovery, scientists have theorised over its purpose. The most commonly accepted theory of its function is that it was an analog computer designed to model the movements of heavenly objects. Recent working reconstructions of the device support this analysis. The device is all the more impressive for its use of a differential gear, which was previously believed to have only been invented in the 16th century

1909  -     Professor Julius Sumner Miller is born. 

Julius Sumner Miller, the man who popularised science with children, was born on 17 May 1909. Sumner Miller studied under Albert Einstein, but was best known for his work on children's television programs, being Disney's "Professor Wonderful" on The Mickey Mouse Club and in Canada, the "mad professor" on The Hilarious House of Frightenstein. In Australia, Sumner Miller's catchphrase was "Why is it so?", and this was also the title of his show which was broadcast from 1963 to 1986. In "Why Is It So?", he piqued children's (and adults') curiosity by investigating common questions by using common household equipment to conduct experiments.

One of Sumner Miller's more popular experiments showed how air pressure could exert sufficient force on a boiled egg (with shell removed) to push it into a milk bottle which had an opening of lesser circumference than that of the egg. Unfortunately, Sumner Miller omitted information on how to then remove the egg: subsequently, milk factories all over Australia encountered the problem of having to scrap returned milk bottles with boiled eggs inside.

Sumner Miller died of leukaemia on 14 April 1987. 

1943  -     The Day of the Dam-Busters: During WW2, Britain carries out strategic bombing attacks on crucial dams in Germany's industrial region.

The Ruhr Valley in northwestern Germany was Germany's main industrial region during the first half of the twentieth century. Bordered by the Ruhr, Rhine and Lippe Rivers, it holds three major dams, the Möhne, Sorpe and the Edersee Dams, which were key producers of hydroelectric power during World War II. The industrial area was also central to the manufacture of Germany's war munitions.

During World War II, the dams became the target of a series of bold bombing raids by Britain's Royal Air Force (RAF). The "bouncing bomb" was invented and developed by Barnes Wallis, Assistant Chief Designer at British engineering firm Vickers. When dropped from the correct angle and height, the bomb was designed to skip over the surface of the water, thus avoiding obstacles such as torpedo nets. After executing a series of bounces, it would reach the dam wall, where its residual backward spin would cause the bomb to run down the side of the dam to its underwater base, exploding and damaging the dam wall. Codenamed Operation Chastise, the raid was carried out over the night of 16-17 May 1943. It was a dangerous assignment as the aircraft dropping the bombs had to avoid German anti-aircraft fire while flying low enough to deploy the bombs. 53 of the 133 aircrew who participated in the attack were killed. The dam walls of the Möhne and Edersee were destroyed, while the Sorpe received minor damage. With an estimated two-thirds of the area's water supply compromised, massive flooding inundated the Ruhr Valley. Several underground mines were flooded, numerous factories were destroyed and over a hundred damaged, along with over a thousand houses. Many roads, railways and bridges were flooded in a radius of about 80km from the breaches. Two hydro-electric powerplants were destroyed and seven others damaged, causing massive disruption to the industrial region for at least two weeks. At least 1,650 people were killed, and hundreds more were never found: over one thousand of these were foreign prisoners of war and forced-labourers, mostly from the Soviet Union prison camps.

Although later analysis indicates the operation was not the military and strategic success it was believed to be at the time, it proved to be a tremendous morale-booster for the British. An interesting, although unexpected, result was the development of improved bombing technology as a result of acceptance of Barnes Wallis's ideas. His concept of "earthquake bombing", which had been previously rejected, was now accepted. This involved dropping a large, specially designed heavy bomb at supersonic speed so it penetrated underground and exploded, with the resulting shockwaves producing the equivalent of a small earthquake. Nearby structures such as dams, railways, viaducts and other crucial infrastructure would be destroyed, especially as any concrete foundations served to magnify the effects of the bomb. Ultimately, this led to the development of the Tallboy and Grand Slam bombs, which caused catastrophic damage to German infrastructure in the latter part of the war.

1973  -     Televised hearings begin on the Watergate affair. 

Cheers - John