A sea generally refers to a large body of salt water, but the term is used in other contexts as well. Most commonly, it means a large expanse of saline water connected with an ocean, and is commonly used as a synonym for ocean. It is also used sometimes to describe a large saline lake that lacks a natural outlet, such as the Caspian Sea.

Arctic (belonging to the Arctic Ocean) and Antarctic (Southern Ocean) seas, as well as some other seas freeze in winter. This occurs below the freezing point of pure water, at about -1.8 °C (28.8 °F). Frozen salt water becomes sea ice.

Humans navigated seas from antiquity. Ancient Egyptians and Phoenicians navigated the Mediterranean Sea and the Red Sea. Hannu was the first see explorer of whom there is any information. He sailed along the Red Sea and further to the Arabian Peninsula and the African Coast around 2750 BC. In the 1st millennium BC, Phoenicians and Greeks established colonies all over the Mediterranean, including its outlets like the Black Sea. The seas along the eastern and the southern Asian coast were used by Arabs and Chinese for navigation, and the North Sea and the Baltic Sea were known to Europeans in Roman times. Other seas were not used for navigation in the antiquity and were actually discovered.

Dark horse is a term used to describe a little-known person or thing that emerges to prominence, especially in a competition of some sort or a contestant that seems unlikely to succeed.

The term began as horse racing parlance. A dark horse is a race horse that is not known to gamblers and thus is difficult to place betting odds on.

The earliest-known use of the phrase is in Benjamin Disraeli's novel The Young Duke (1831). Disraeli's protagonist, the Duke of St. James, attends a horse race with a surprise finish: "A dark horse which had never been thought of, and which the careless St. James had never even observed in the list, rushed past the grandstand in sweeping triumph."

The term has been used politically in such countries as Peru, Philippines and United States.

Politically, the term reached America in the nineteenth century when it was first applied to James K. Polk, a relatively unknown Tennessee Democrat who won the Democratic Party's 1844 presidential nomination over a host of better-known candidates. Polk won the nomination on the ninth ballot, and went on to win the presidential election.

Porter Robinson (born July 15, 1992) is an American electronic dance music producer and DJ from Chapel Hill, North Carolina. He primarily produces in the electro house genre. He also named the genre complextro when he created the portmanteau to describe his own sound.

Porter Robinson began producing at the age of 13 using Sony ACID Pro emulating sounds he heard from video games. He later began producing hands-up under the alias Ekowraith using FL Studio. It was at this time that Robinson became friends with a young Madeon, who was also producing hands-up under the name Deamon, and also using FL Studio.

Robinson primarily uses Lennard Digital Sylenth1, Native Instruments Massive, 3xOsc, Sytrus and several other commercial and free audio plugins.

He is currently 19 years old and recently graduated high school in his hometown of Chapel Hill, North Carolina.

He has released a variety of original singles on Glamara Records and Big Fish Recordings. His first single, "Say My Name", was an enormous success, landing at #1 on Beatport's Electro House chart. In the summer of 2011 he signed with OWSLA, a new label operated by Skrillex, to release his first EP entitled Spitfire. Spitfire reached the number one spot on the iTunes Dance chart as well as the number one spot on Beatport's overall release chart.