Renaissance

Renaissance “re-birth”, Italian: Rinascimento, from rinascere “to be reborn”) [1] was a cultural movement that spanned the period roughly from the 14th to the 17th century

Picasso & Chicago

A century ago, in 1913, the Art Institute of Chicago became the first art museum in the country to present the work of a young Spaniard who would become the preeminent artist of the 20th century, Pablo Picasso. This February the museum celebrates the special 100-year relationship between Picasso and Chicago by bringing together over 250 of the finest examples of the artist’s paintings, sculpture, prints, drawings, and ceramics from private collections in the city, as well as from the museum’s collection, for the first large-scale Picasso exhibition organized by the museum in almost 30 years.

After first showing artworks by Picasso in the 1913 Armory Show, the museum began collecting his works in the early 1920s with two figural drawings, Study of a Seated Man (1905) and Sketches of a Young Woman and a Man (1904/05); in 1926 the museum welcomed The Old Guitarist (late 1903–early 1904) as a generous gift of Frederic Clay and Helen Birch Bartlett. Over time, the collection has expanded to include paintings such as the classically inspired Mother and Child (1921) and the surrealist Red Armchair (1931); landmark sculptures including the Cubist Head of a Woman (Fernande) (1909) and a maquette for Picasso’s largest three-dimensional work, Monument for Richard J. Daley Plaza (1965); and works on paper such as Woman Washing Her Feet (1944) and impressions of The Frugal Meal (1904), one of only three examples in the world of the famous Blue Period etching actually printed in blue ink.

Featuring such diverse and significant works from the museum’s own exceptional holdings and from collections throughout the city, Picasso and Chicago not only charts the full gamut of Picasso’s artistic career but also chronicles the growth of Chicago as a place for modern art and the storied moments of overlap that have contributed to the vibrant interest in Picasso from 1913 to today.

Space Elevator

space elevator is a proposed type of space transportation system. Its main component is a ribbon-like cable (also called a tether) anchored to the surface and extending into space. It is designed to permit vehicle transport along the cable from a planetary surface, such as the Earth’s, directly into space or orbit, without the use of large rockets. An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit (35,800 km altitude). The competing forces of gravity, which is stronger at the lower end, and the outward/upward centrifugal force, which is stronger at the upper end, would result in the cable being held up, under tension, and stationary over a single position on Earth. Once deployed, the tether would be ascended repeatedly by mechanical means to orbit, and descended to return to the surface from orbit.

The concept for a space elevator was first published in 1895 by Konstantin Tsiolkovsky, and has since been promoted by legendary scientist and visionary Sir Arthur C Clarke. His proposal was for a free-standing tower reaching from the surface of Earth to the height of geostationary orbit. Like all buildings, Tsiolkovsky’s structure would be under compression, supporting its weight from below. Since 1959, most ideas for space elevators have focused on purely tensile structures, with the weight of the system held up from above. In the tensile concepts, a space tether reaches from a large mass (the counterweight) beyond geostationary orbit to the ground. This structure is held in tension between Earth and the counterweight like an upside-down plumb bob. Space elevators have also sometimes been referred to as beanstalks, space bridges, space lifts, space ladders, skyhooks, orbital towers, or orbital elevators.

On Earth, with its relatively strong gravity, current technology is not capable of manufacturing tether materials that are sufficiently strong and light to build a space elevator. However, recent concepts for a space elevator are notable for their plans to use carbon nanotube or boron nitride nanotube based materials as the tensile element in the tether design. The measured strength of these molecules is high compared to their densities and they hold promise as materials to make an Earth-based space elevator possible.

The concept is also applicable to other planets and celestial bodies. For locations in the solar system with weaker gravity than Earth’s (such as the Moon or Mars), the strength-to-density requirements are not as great for tether materials. Currently available materials (such as Kevlar) are strong and light enough that they could be used as the tether material for elevators there.

The Battle of River Plate

The Battle of River Plate took place on December 13th 1939. The battle in the South Atlantic was the first major naval battle of World War Two. Ships from the Royal Navy’s South American Division took on the might of Germany’s Graf Spee which was successfully attacking merchant shipping in the South Atlantic.

Great Britain’s South American Naval Division was made up of four cruisers. On Saturday, December 2nd, 1939, HMS Ajax, commanded by Captain Woodhouse, was harboured at Port Stanley in the Falkland Islands. Also at Port Stanley was HMS Exeter, commanded by Captain Bell. Two other ships made up the South American Division – HMS Cumberland, commanded by Captain Fallowfield, and HMNZSAchilles, commanded by Captain Parry. The commander of the South American Division was Commodore Harwood.

Harwood knew that the Graf Spee was in the South Atlantic somewhere but he had received no intelligence since November 15th as to her exact position. Harwood came to two conclusions:

There were three neutral countries in South America that allowed ships to use their harbour facilities – Argentina, Brazil and Uruguay. Under international law, a naval ship could only use a harbour once every three months. However, Harwood had built up a number of contacts in each country and this ‘law’ was given a liberal interpretation by both parties.

On December 2nd, 1939, Harwood received a message that a merchant ship, the ‘Doric Star’ had been attacked by a large German naval vessel just off St. Helena. The next day, Harwood was informed that another ship, the ‘Tairoa’, had also been attacked 170 miles to the south-west of where the ‘Doric Star’ had been attacked. Harwood assumed that it was the ‘Graf Spee’. By using the distance covered over 24 hours, Harwood estimated where this German naval ship could be. He worked off of an average speed of 15 knots an hour – in fact, the Graf Spee cruised at 22 knots; 50% faster than that estimated by the British. However, luck also assisted Harwood’s skill. The Graf Spee’s average speed was 22 knots – but it had been reduced as a result of the Graf Spee’s attacks on merchant shipping……to 15 knots, exactly what Harwood had calculated.

Harwood could not split his force of four cruisers so he decided that out of his two obvious choices, the River Plate in Argentina and Rio de Janeiro in Brazil, he would place his force at the mouth of the River Plate and wait. Even so, Harwood had to assume that the Graf Spee would go to South America – what if it turned to the West Indies?

On paper, four British cruisers against one German pocket-battleship would have been no contest. In fact, the Graf Spee was potentially an awesome opponent. The Treaty of Versailles had forbidden Germany from making what would have been considered to be classic battleships. To get round the restrictions of Versailles, Germany produced pocket battleships. The Graf Spee was commissioned in 1936. The Graf Spee was fast enough to outrun any battleship but was also armed with sufficient weapons to be a potent enemy. The Graf Spee had six 11 inch guns, numerous anti-aircraft guns and six 21 inch torpedo tubes at her stern. Her broadside range was 30,000 yards. She carried two Arado aircraft that could be launched by catapult. Her weaponry was superior to any carried by a British heavy cruiser and her armour, at 5.5 inches, was sufficient to resist shells up to 8 inches. Her eight diesel engines gave the ship 56,000 horsepower and a top speed of 26 knots. The engines also allowed the Graf Spee to travel 12,500 miles without refueling – near enough halfway round the world.

In the Battle of the River Plate, the Graf Spee was to be pitted against British cruisers. Though faster than the Graf Spee, they were all outgunned. The Exeter had six 8 inch guns, a top speed of 31 knots but her broadside range was 27,000 yards. Ajax, seen below, and Achilles had a smaller broadside range of 25,000 yards and were equipped with eight 6 inch guns.

The commander of the Graf Spee, Langsdorff, knew that he had range on his side and he could effectively engage the enemy while they could not engage him – as long as the Graf Spee kept its distance. The only threat in terms of distance was the Exeter – if the Graf Spee took the Exeter out of any battle, Langsdorff knew that he was relatively free of trouble. For Harwood, he knew that he had speed on his side and that he could keep out of the range of the Graf Spee but keep up with her, trailing her, until bigger reinforcements arrived.

On December 13th, 1939, the Graf Spee was targeting the route used by merchant ships near the River Plate in Argentina. Harwood had given the Ajax, Achilles and Exeter orders to engage the Graf Spee “at once by night or day” if the ships came across her.

At 05.52, look outs on the Graf Spee saw two tall masts on the horizon. By 06.00, Langsdorff had identified one of the ships seen as being the Exeter. He decided that the ships trailing the Graf Spee were protecting an important merchant convoy and he decided to attack. The engines of the Graf Spee were put onto a battle footing – their power was greatly increased. This gave out a plume of highly visible black smoke from the funnels of the Graf Spee and the following British cruisers could clearly see her position. The Graf Spee turned to attack and at 06.17 opened fire on the Exeter. The Exeter was hit amidships and the ship sustained damage. A salvo from the Graf Spee did a great deal of damage to the wheelhouse and killed all but three of the officers in it. The captain, Bell, survived and he ordered that the remaining turrets should fire on the Graf Spee. One salvo hit the Graf Spee near its turrets.

The Achilles and Ajax were also involved in this battle but they had stayed away from the Exeter in an attempt to split the Graf Spee’s fire power. It proved to be a successful ploy. More shells from the Graf Spee’s 11 inch guns hit the Exeter that continued to take massive damage. However, some of the Exeter’s torpedo tubes were undamaged and at 06.31, three torpedoes were fired at the Graf Spee from the Exeter. At that moment, Langsdorff had decided to turn and the three torpedoes missed. His attack on the Exeter continued and 11 inch shells hit the cruiser. However, the engine room was not damaged but electricity in the ship was lost and it was this that forced the Exeter out of the battle. Bell planned to ram the Graf Spee but he was ordered out of the battle by Harwood.

Now the Achilles and Ajax took up the battle. They were against a ship that had been hit but had suffered minimal damage at this stage even though Langsdorff had been knocked unconscious in one attack. Both ships were ordered by Harwood to approach the Graf Spee “at the utmost speed”.  Langsdorff, a torpedo specialist, kept both ships astern to give them the smallest possible target with regards to a torpedo attack.

What happened next is open to interpretation. Langsdorff went around the Graf Spee to assess the damage. He then told his navigator:

This decision, according to the Graf Spee’s gunnery officer was not well received. The ship had been hit by seventeen shells but junior officers of the Graf Spee later stated that the damage done to the ship was insufficient to cause it to run to a port. At this stage in the battle, the Graf Spee had suffered 37 dead and 57 wounded out of a total complement of 1,100. In comparison, the Exeter was three feet down in the waterline and had lost 61 men killed and could only use a ship’s compass for navigation with shouted orders to ensure that those orders were carried out. Harwood ordered her to return to the Falkland Islands.

All the indications pointed to the Graf Spee heading towards the River Plate and Montevideo. In fact the ship’s action report states clearly that it was the navigating officer that recommended Montevideo. Langsdorff sent a telegram to Berlin that stated:

Whether the Graf Spee was so badly damaged is open to question. The ship had been hit by seventeen shells but one gunnery officer recorded that three of these hits had simply bounced off of the armour and that the others had hit the ship “without causing damage”. The authorities in Uruguay, on inspecting the Graf Spee when it reached the River Plate, commented that the largest hit was six feet by six feet but was well above the waterline – as was all of the damage to the ship.

The Graf Spee made for the River Plate – the Plate estuary is a huge bay 120 miles across. The two remaining cruisers, Ajax and Achilles, patrolled the estuary to ensure that the Graf Spee could not slip out back into the Atlantic under the cover of dark. The crews later called this the ‘death watch’.