Flat feet, or fallen arches, may cause a number of health problems.
The excellent archers were feared members of the Persian army
Plants are capable of converting inorganic substances (carbon dioxide and water) into organic sugar.
This animation demonstrates the structure of water towers.
The mummified body of a man who probably lived in the Chalcolithic period, was found in one of the glaciers of the Alps.
The Rietveld Schröder House, located in the town of Utrecht in the Netherlands, can be considered a forerunner of modern houses.
The small passenger aircraft is designed for speed, convenience and economical operation.
The Jumbo Jet is one of the best known airliners.
Groups of western jackdaws are frequently found in cities. Konrad Lorenz analysed the complex social behaviour of these animals.
Change of light conditions in different seasons. Measuring height using shadows.
Giant sequoias are the world's largest living organisms by mass.
Large, extinct species of cats named after the shape of their large canine teeth.
The saker falcon is a large bird of prey widespread in Europe and and Asia.
Amino acids that make up proteins are bound by peptide bonds.
The poisonous bite of the Chilean recluse spider poses a serious threat to human health.
This animation presents the current refugee crisis from various points of view.
The Orthodox church, situated on a picturesque cliff, was named after John the Apostle
Rotating a rectangle around its axes of symmetry or around its sides results in solids of revolution.
The Mir Castle Complex, situated in the town of Mir, Belarus was built in the Gothic-Renaissance style.
Colourless, odourless gas, highly toxic to humans and animals in high concentration.