An average Egyptian dwelling consisted of regularly arranged rooms.
A dynamo converts mechanical energy into direct current.
Lightning is a sudden electrostatic discharge accompanied by a sound known as thunder.
The diameter of the Sun is about 109 times that of the Earth. Most of its mass consists of hydrogen.
The eye is one of our most important sense organs. When stimulated by light, electric impulses are produced by its receptors.
Located close to Osaka, the Japanese castle is also called the White Heron because of its white exterior.
The Earth is composed of several spherical layers.
The orbits of the 8 planets in our Solar System are elliptical.
Due to the Earth´s tilted axis, the angle of the Sun's rays at given latitudes continuously changes during the year.
The geographic coordinate system enables every location on the Earth to be exactly specified.
The difference between the temperature of the polar and equatorial zones causes atmospheric circulation which is affected by a number of factors, including...
The International Space Station is a habitable satellite built with the cooperation of 16 countries.
Lymph vessels carry lymph to the blood vessels, while lymph nodes are integral parts of the immune system.
Aluminium smelting is the process of extracting aluminium from alumina by electrolysis.
Eukaryotic cells contain a number of organelles.
The ribs, the sternum and the spinal column form the skeleton of the chest.
Bacteria occur in a wide range of shapes, including spheres, rods and spirals.
Bottlenose dolphins are sea mammals which use ultrasound for orientation.
This animation introduces the most important systems of the human body.
This animation demonstrates the functioning of the 3 basic types of water tap.