Windmill

A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain, pump water, or both. Thus they often were gristmills, windpumps, or both. The majority of modern windmills take the form of wind turbines used to generate electricity, or windpumps used to pump water, either for land drainage or to extract groundwater.

Windmills in antiquity

The windwheel of the Greek engineer Heron of Alexandria in the first century is the earliest known instance of using a wind-driven wheel to power a machine. Another early example of a wind-driven wheel was the prayer wheel, which has been used in Tibet and China since the fourth century. It has been claimed that the Babylonian emperor Hammurabi planned to use wind power for his ambitious irrigation project in the seventeenth century BCE.

Horizontal windmills

The first practical windmills had sails that rotated in a horizontal plane, around a vertical axis. According to Ahmad Y. al-Hassan, these panemone windmills were invented in eastern Persia as recorded by the Persian geographer Estakhri in the ninth century. The authenticity of an earlier anecdote of a windmill involving the second caliph Umar (AD 634–644) is questioned on the grounds that it appears in a tenth-century document. Made of six to 12 sails covered in reed matting or cloth material, these windmills were used to grind grain or draw up water, and were quite different from the later European vertical windmills. Windmills were in widespread use across the Middle East and Central Asia, and later spread to China and India from there.

Grand Theft Auto V

Grand Theft Auto V is an open world, action-adventure video game developed by Rockstar North and published by Rockstar Games. It was released on 17 September 2013 for the PlayStation 3 and Xbox 360, on 18 November 2014 for the PlayStation 4 and Xbox One, and on 14 April 2015 for Microsoft Windows. The game is the first main entry in the Grand Theft Auto series since 2008's Grand Theft Auto IV. Set within the fictional state of San Andreas, based on Southern California, the single-player story follows three criminals and their efforts to commit heists while under pressure from a government agency. The open world design lets players freely roam San Andreas's open countryside and fictional city of Los Santos, based on Los Angeles.

The game is played from either a first-person or third-person view and its world is navigated on foot or by vehicle. Players control the three lead protagonists throughout single-player and switch between them both during and outside of missions. The story is centred on the heist sequences, and many missions involve shooting and driving gameplay. A "wanted" system governs the aggression of law enforcement response to players who commit crimes. Grand Theft Auto Online, the online multiplayer mode, lets up to 30 players explore the open world and engage in cooperative or competitive game matches.