Solar eclipse and lunar eclipse

We can observe quite interesting astronomical phenomena when the Earth, the Sun and the Moon align.

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Folding (intermediate)

Lateral compressive forces cause rocks to form folds. This is how fold mountains are...


Waves play an important role in forming the coast.


The circumference of the Earth has already been calculated in ancient Egypt. The...

Continental drift

In the past, a number of geologists tried to explain why the outlines of continents...

Protecting natural waters

Water is one of our key natural resources; we must protect it vigorously.

The Gregorian calendar

Developed nearly 500 years ago, it is a variant of the Julian calendar. Today it is...

Plate tectonics

Plate tectonics is a theory dealing with the movement of plates.

Tectonic plates

Tectonic plates can move in relation to each other.

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