The "Titanic" disaster changed many maritime ship laws. Because so many people died, authorities felt that laws should be put into place to make ship travel safer. Changes included requiring all ships to carry enough lifeboats for everyone on the ship, and emergency materials such as flares. Someone must be at the ship's radio all the time.
Alexander Brehm, a German physicist, was shocked when he heard about the disaster. He wanted to invent a technology that would be able to detect icebergs. He wasn't able to achieve that goal until his death, but he was granted patents relating to the measurement of the depth at sea, using sound. Today, this is known as echo sounding.
The wreck was found by a French and American team, led by Robert Ballard, on September 1, 1985 at 1:02 in the morning.
In 1986, Ballard returned to the wreck with a submarine. He took many photos and made lots of films.
In 1987, a French team salvaged 900 objects and took them to the surface.
The story of the sinking has been made into several movies. The most popular film version is a 1997 film starring Kate Winslet and Leonardo DiCaprio called "Titanic". It won 11 Academy Awards, tying "Ben-Hur" for the record for the most Academy Awards won by one movie.
Other movie versions of the story include the 1958 film "A Night to Remember", the 1953 film "Titanic", the 1979 film "S.O.S. Titanic "and the 1996 movie "Titanic".
In the 1980 film Raise the Titanic, salvagers raise the shipwreck from the bottom of the ocean to the surface. However, this is impossible to do in reality. The "Titanic" broke in two, and the wreck is partially stuck in the bottom, buried under more than three feet (1 m) of mud in some spots. The ship has been on the ocean floor for more than 100 years, and would shatter into many more pieces if disturbed. Worms and other animals have eaten away much of the wood and many other parts.
Steel
Steel is iron mixed with carbon and perhaps other metals. It is harder and stronger than iron. Iron with more than 1.7% percent carbon by weight is named cast iron. Steel is different from wrought iron, which has little or no carbon.
Steel has a long history. People in India and Sri Lanka were making small amounts of steel more than 2,500 years ago. It was very expensive and was often used to make swords and knives. In the Middle Ages, steel could be made only in small amounts since the processes took a long time.
In the time since, there have been many changes to the way steel is made. In about the year 1610 steel started to be made in England, and the way it was made got better and cheaper over the next 100 years. Cheap steel helped start the Industrial Revolution in England and in Europe. The first industrial Converter (metallurgy) for making cheap steel was the Bessemer converter, followed by Siemens-Martin open-hearth process.
Today the most common way of making steel is the basic-oxygen process. The converter is a large turnip-shaped vessel. Liquid raw iron called "pig iron" is poured in and some scrap metal is added in to balance the heat. Oxygen is then blown into the iron. The oxygen burns off the extra carbon and other impurities. Then enough carbon is added to make the carbon contents as wanted. The liquid steel is then poured. It can be either cast into molds or rolled into sheets, slabs, beams and other so-called "long products", such as railway tracks. Some special steels are made in electric arc furnaces.
Steel is most often made by machines in huge buildings called "steel mills". It is a very cheap metal and is used to make many things. Steel is used in making buildings and bridges, and all kinds of machines. Almost all ships and cars are today made from steel. When a steel object is old, or it is broken beyond repair, it is called "scrap". It can be melted down and re-shaped into a new object. Steel is "recyclable" material; that is, the same steel can be used and re-used.
Steel is a metal alloy which includes iron and often some carbon.
Every material is made up of atoms which are very small parts. Some atoms hold together quite well, which is what makes some solid materials hard. Something made of pure iron is softer than steel because the atoms can slip over one another. If other atoms like carbon are added, they are different from iron atoms and stop the iron atoms from sliding apart so easily. This makes the metal stronger and harder.
Changing the amount of carbon (or other atoms) added to steel will change those things that are interesting and useful about the metal. These are called the properties of the steel. Some properties are:
Steel with more carbon is harder and stronger than pure iron, but it also breaks more easily (brittle).
There are thousands of steel types. Each type is made of different chemical elements.
All steels have some elements that have a bad effect, such as phosphorus (P) and sulphur (S). Steel makers take out as much P and S as possible.
Plain carbon steels are made only of iron, carbon, and undesired elements. They fall into three general groups. Plain carbon steel with 0.05 to 0.2% carbon does not harden when cooled quickly. Welding it is simple, so it is used for shipbuilding, boilers, pipes, fence wire and other purposes where low cost is important. Plain steels are used for springs, gears, and engine parts. Plain carbon steel with 0.45 to 0.8% carbon is used for very hard items such as shears and machine tools.
Alloy steels are plain carbon steel with metals such as Boron (B), manganese (Mn), chromium (Cr), nickel (Ni), molybdenum (Mo), tungsten (W), and cobalt (Co) added. These give other properties than plain carbon steel. Alloy steels are made for specialized purposes. For example, chromium can be added to make stainless steel, which does not rust easily, or boron can be added to make very hard steel that is also not brittle.
There are a huge number of things that people make from steel. It is one of the most common and useful metals.
A lot of items made from iron in the past are now made of steel. Some of them are:
Luftwaffe
The Luftwaffe (pronounced ) is the name for the air force of Germany. It was the name for the air force of Germany during the Third Reich when Adolf Hitler was in power (between 1933 and 1945). It has also been the name for the air force since it was re-established in 1955 during the era of the Cold War. Luftwaffe means Air weapon in English.
Germany first had aeroplanes in its army in 1910, four years before the start of World War I in 1914. At that time, aeroplanes had no guns. They were being used for reconnaissance duties. They would fly over the battlefield to see what the enemy was doing and fly back so that the pilots could tell their generals what they knew. The generals used that information to help plan the fighting.
During World War I, Germany created the "Luftstreitkräfte", known in English as the Imperial German Air Service. The German navy also had its planes in the Marine-Fliegerabteilung.
Guns were fitted to planes in 1915.
The fighter aeroplanes became very famous because of its brave pilots. The most famous German pilot of World War I was Manfred von Richthofen, also known as "The Red Baron" of Jasta 11. When he died in combat, Hermann Goering replaced him.
Germany also used airships called "Zeppelins". They were named after Count Ferdinand von Zeppelin, who had built the first airships in 1900. He had wanted them to carry cargo and passengers, not bombs. He died in 1917.
In November 1918, the "Allies of World War I" (which included Britain and France) won the war, and Germany had to sign the Treaty of Versailles. The treaty said that Germany could not have any military aeroplanes at all because it was blamed for starting the war in 1914. Germany therefore had to destroy all its military aeroplanes as a punishment, so until 1933 it had no air force at all.