Cortical organization of speech

Producing speech requires the synchronized operation of several cortical centers.

Conic sections

The conic section is a plane curve that is created when a right circular cone is intersected by a plane.

Wind power station

Wind power stations convert the kinetic energy of the wind into electricity.

Meteorological instruments

This animation demonstrates instruments used to examine atmospheric phenomena.

Medieval keep

Keeps were typical buildings in the Middle Ages, also built independently from castles.

Generating alternating current

Electric current can be generated by rotating an armature loop in a magnetic field.

How does it work? - Escalator

This animation demonstrates how an escalator works.

Carbonic acid (H₂CO₃)

Colorless, odorless liquid produced by dissolving carbon dioxide in water.

Hexagonal metallic lattice

Metals forming hexagonal metallic lattices are rigid and difficult to machine.


A group of fish characterized by a cartilaginous skeleton, well-known species include the great white shark and the hammerhead shark.


Enzymes are protein molecules catalyzing biochemical reactions. Their activity can be regulated.

Hubble Space Telescope

The Hubble Space Telescope orbits outside the distorting influence of Earth´s atmosphere.

Medical conditions of the spine

Scoliosis is a medical condition in which a person's spine has a lateral deviation.

Electric surface transportation

Trolleybuses and streetcars are environment-friendly means of public transportation

Conquistador (16th century)

Spanish conquerors owed their success to their armor and firearms.

Aurora cruiser ship (1900)

The name of the Russian armored cruiser became well known during the October Revolution of 1917.

Seeds and germination

Dicotyledons have two embryonic leaves (cotyledons), while monototyledons have only one.

Wooly mammoth

Extinct proboscidea closely related to today's elephants, often hunted by prehistoric man.

English battleship (18th century)

English sailing ships were among the best ships in the 17th-19th centuries.

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