An unmanned aerial vehicle (UAV), commonly known as a drone, as an unmanned aircraft system (UAS), or by several other names, is an aircraft without a human pilot aboard. The flight of UAVs may operate with various degrees of autonomy: either under remote control by a human operator, or fully or intermittently autonomously, by onboard computers.

Compared to manned aircraft, UAVs are often preferred for missions that are too “dull, dirty or dangerous” for humans. They originated mostly in military applications, although their use is expanding in commercial, scientific, recreational, agricultural, and other applications, such as policing and surveillance, aerial photography, agriculture and drone racing. Civilian drones now vastly outnumber military drones, with estimates of over a million sold by 2015.

The term drone, more widely used by the public, was coined in reference to the resemblance of dumb-looking navigation and loud-and-regular motor sounds of old military unmanned aircraft to the male bee. The term has encountered strong opposition from aviation professionals and government regulators.

“Worker bees can leave.
Even drones can fly away.
The Queen is their slave.”
— Chuck Palahniuk

The term unmanned aircraft system was adopted by the United States Department of Defense and the United States Federal Aviation Administration in 2005 according to their Unmanned Aircraft System Roadmap 2005–2030. The International Civil Aviation Organization and the British Civil Aviation Authority adopted this term, also used in the European Union’s Single-European-Sky  Air-Traffic-Management Research roadmap for 2020. This term emphasizes the importance of elements other than the aircraft. It includes elements such as ground control stations, data links and other support equipment. A similar term is an unmanned-aircraft vehicle system remotely piloted aerial vehicle, remotely piloted aircraft system. Many similar terms are in use.

A UAV is defined as a “powered, aerial vehicle that does not carry a human operator, uses aerodynamic forces to provide vehicle lift, can fly autonomously or be piloted remotely, can be expendable or recoverable, and can carry a lethal or nonlethal payload”. Therefore, missiles are not considered UAVs because the vehicle itself is a weapon that is not reused, though it is also unmanned and in some cases remotely guided.

The relation of UAVs to remote controlled model aircraft is unclear. UAVs may or may not include model aircraft.[citation needed] Some jurisdictions base their definition on size or weight, however, the US Federal Aviation Administration defines any unmanned flying craft as a UAV regardless of size. A radio-controlled aircraft becomes a drone with the addition of an autopilot artificial intelligence (AI), and ceases to be a drone when the AI is removed.
The earliest attempt at a powered UAV was A. M. Low’s “Aerial Target” in 1916. Nikola Tesla described a fleet of unmanned aerial combat vehicles in 1915. Advances followed during and after World War I, including the Hewitt-Sperry Automatic Airplane. The first scaled remote piloted vehicle was developed by film star and model-airplane enthusiast Reginald Denny in 1935. More emerged during World War II – used both to train antiaircraft gunners and to fly attack missions. Nazi Germany produced and used various UAV aircraft during the war. Jet engines entered service after World War II in vehicles such as the Australian GAF Jindivik, and Teledyne Ryan Firebee I of 1951, while companies like Beechcraft offered their Model 1001 for the U.S. Navy in 1955. Nevertheless, they were little more than remote-controlled airplanes until the Vietnam War.

In 1959, the U.S. Air Force, concerned about losing pilots over hostile territory, began planning for the use of unmanned aircraft.Planning intensified after the Soviet Union shot down a U-2 in 1960. Within days, a highly classified UAV program started under the code name of “Red Wagon”. The August 1964 clash in the Tonkin Gulf between naval units of the U.S. and North Vietnamese Navy initiated America’s highly classified UAVs

Marine biology is the scientific study of organisms in the ocean or other marine bodies of water. Given that in biology many phyla, families and genera have some species that live in the sea and others that live on land, marine biology classifies species based on the environment rather than on taxonomy. Marine biology differs from marine ecology as marine ecology is focused on how organisms interact with each other and the environment, while biology is the study of the organisms themselves.

A large proportion of all life on Earth lives in the ocean. Exactly how large the proportion is unknown, since many ocean species are still to be discovered. The ocean is a complex three-dimensional world covering approximately 71% of the Earth’s surface. The habitats studied in marine biology include everything from the tiny layers of surface water in which organisms and abiotic items may be trapped in surface tension between the ocean and atmosphere, to the depths of the oceanic trenches, sometimes 10,000 meters or more beneath the surface of the ocean.

Specific habitats include coral reefs, kelp forests, seagrass meadows, the surrounds of seamounts and thermal vents, tidepools, muddy, sandy and rocky bottoms, and the open ocean (pelagic) zone, where solid objects are rare and the surface of the water is the only visible boundary. The organisms studied range from microscopic phytoplankton and zooplankton to huge cetaceans (whales) 30 meters (98 feet) in length.

“The water was tripping over itself, splashing and hypnotizing, and I tried to fix my mind on a chunk of it, like each little ripple was a life that began far away in a high mountain source and had traveled miles pushing forward until it arrived at this spot before my eyes, and now without hesitation that water-life was hurling itself over the cliff. I wanted my body in all that swiftness; I wanted to feel the slip and pull of the currents and be dashed and pummeled on the rocks below . . .”
— Justin Torres (We the Animals)

Marine life is a vast resource, providing food, medicine, and raw materials, in addition to helping to support recreation and tourism all over the world. At a fundamental level, marine life helps determine the very nature of our planet. Marine organisms contribute significantly to the oxygen cycle, and are involved in the regulation of the Earth’s climate. Shorelines are in part shaped and protected by marine life, and some marine organisms even help create new land.

Many species are economically important to humans, including both finfish and shellfish. It is also becoming understood that the well-being of marine organisms and other organisms are linked in fundamental ways. The human body of knowledge regarding the relationship between life in the sea and important cycles is rapidly growing, with new discoveries being made nearly every day. These cycles include those of matter (such as the carbon cycle) and of air (such as Earth’s respiration, and movement of energy through ecosystems including the ocean). Large areas beneath the ocean surface still remain effectively unexplored.
Early instances of the study of marine biology trace back to Aristotle (384–322 BC) who made several contributions which laid the foundation for many future discoveries and were the first big step in the early exploration period of the ocean and marine life. In 1768, Samuel Gottlieb Gmelin  published the Historia Fucorum, the first work dedicated to marine algae and the first book on marine biology to use the then new binomial nomenclature of Linnaeus. It included elaborate illustrations of seaweed and marine algae on folded leaves.The British naturalist Edward Forbes (1815–1854) is generally regarded as the founder of the science of marine biology.[9] The pace of oceanographic and marine biology studies quickly accelerated during the course of the 19th century.