Producing speech requires the synchronised operation of several cortical centres.
Concave and convex lenses are used for the correction of short-sightedness and far-sightedness.
The Chengdu J-20, also known as Mighty Dragon, is a multiple function stealth fighter aircraft.
The colonising powers´ colours were wiped off the map by the nations fighting to regain their independence.
The Earth is divided into 24 time zones. Standard time is the time used within time zones.
Tidal power stations utilise the daily fluctuation of the water level for producing electricity.
As opposed to underground mines, in open-pit mines the layers covering coal are removed, coal is extracted on the surface.
Treated sewage water can be used in agriculture and industry.
Raw iron is produced from iron ore in iron smelters.
English sailing ships were among the best ships in the 17th-19th centuries.
The submarine designed by the Spanish inventor Narcís Monturiol was a pioneering work in the history of underwater navigation.
The design and structure of modern houses play an important role in environmental protection.
The first calendars and time-measuring instruments were already used by ancient Eastern civilisations.
One of the greatest archaeological finds of the 20th century was the tomb of the Egyptian pharaoh.
The animation offers a summary of the history of aviation from the Middle Ages.
The Greek fleet owed their success to their good tactics and their fast and easily manoeuvrable ships.
More than one million people died in the WWII Nazi death camp located in present-day Poland.
This animation demonstrates the five regular three-dimensional (or Platonic) solids, the best known of which is the cube.
Edges, diagonals and faces of a cube can be identified by its vertices.
The Möbius strip and the Klein bottle are special two-dimensional surfaces with only one side.