Geothermal power stations convert energy of hot, high-pressure water found in deeper layers of the Earth into electricity.
Thermal power stations convert energy released during the combustion of fossil fuels or renewable resources into electricity.
During its orbit around the Earth, the visibility of the Moon's illuminated part constantly changes.
Neptune is the outermost planet of the Solar System, the smallest of the giant planets
The palace of Charlemagne was not only the centre of his empire, but also a centre of culture.
The invention of the ballpoint pen made writing a lot easier.
Vertical forces can break up layers of rock into fault blocks, which then move vertically along the fracture planes.
The concentration camp established on Polish territory was the administrative centre of a huge camp complex.
The highway code contains rules concerning the safety equipment of bicycles.
The changing bicycle, at first mocked as a toy, is a true mirror of the technical development over the last three centuries.
The first dwellings in human history provide a lot of information about the lifestyle of our ancestors.
Hero of Alexandria is the inventor of the first steam engine, although he regarded it as an entertaining toy.
Large construction sites provide archaeologists searching for artefacts with a great deal of work.
Submarines had an important role in naval warfare as early as World War I.
The suspension bridge that stretches above the strait between San Francisco Bay and the Pacific Ocean was opened in 1937.
A mobile, nuclear-capable ballistic missile developed at the end of the Cold War.
The Apache attack helicopter, named after an American Indian tribe, was developed for the United States Army.
Static warfare was one of the characteristics of WWI.
The work of smiths – one of the first professions in history – became even more important in the Middle Ages.