The Earth's Atmosphere

The Earth's atmosphere is a layer of gases surrounding the globe Earth and retained by the Earth's magnitude. It contains roughly 78.08% nitrogen, 20.95% oxygen, 0.93% argon, 0.038% carbon dioxide, trace amounts of other gases, and a variable amount (average around 1%) of water vapor. This mixture of gases is commonly known as air. The atmosphere protects life on Earth by absorbing ultraviolet solar emission and reducing temperature extremes between day and night.

There is no definite boundary between the atmosphere and outer space. It slowly becomes thinner and fades into space. Three quarters of the atmosphere's mass is within 11 km of the terrestrial surface. In the United States, people who travel above an elevation of 80.5 km (50 statute miles) are designated astronauts. An altitude of 120 km (~75 miles or 400,000 ft) marks the periphery where distinctive effects become noticeable during re-entry. The Kármán line, at 100 km (62 miles or 328,000 ft), is also frequently regarded as the margin between atmosphere and outer space.

Titanic

The Titanic was a British Olympic-class ocean inside layer, owned by the White Star Line, that struck an iceberg on April 14, 1912 and sank on the morning of April 15, 1912 during her maiden journey across the Atlantic Ocean to New York. Estimates vary, but approximately 1,520 people perished in the sinking which ranks as one of the worst peacetime maritime disasters in history. The resulting media agitation, the discovery of the wreck in 1985, and the box office successes of three major films and one broadway musical have perpetuated the fame. The great loss of life resulted in improved safety standards at sea, and affected many aspects of maritime law.

The Titanic closely resembled her older sister Olympic, but there were a few differences. Two of the most perceptible were that half of the Titanic's forward boulevard A-Deck was enclosed against outside weather, and her B-Deck arrangement was different from the Olympic. The Titanic had a specialty restaurant called Café Parisien, a feature that the Olympic did not have until 1913. Some of the flaws found on the Olympic, such as the creaking of the aft opening out joint, were corrected on the Titanic. The skid lights that provided natural enlightenment on A-deck were round; while on Olympic they were oval. The Titanic's wheelhouse was made narrower and longer than the Olympic's. These, and other modifications, made the Titanic 1,004 gross tons larger than the Olympic and thus the biggest active ship in the world during its maiden voyage in April 1912.