Problem: In classical physics, an inertial reference frame is one in which an object that experiences no forces does not accelerate. In general relativity, an inertial frame of reference is one that is following a geodesic of space-time. An object that moves against a geodesic experiences a force. An object in free fall does not experience a force, because it is following a geodesic. An object standing on the earth, however, will experience a force, as it is being held against the geodesic by the surface of the planet. In light of this, the bucket of water rotating in empty space will experience a force because it rotates with respect to the geodesic. The water will become concave, not because it is rotating with respect to the distant stars, but because it is rotating with respect to the geodesic.
Why will water become concave, according to the relativity theory?
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Answer: it is rotating with respect to the geodesic.


Problem: The capital of Danish Estonia (Danish: Hertugdømmet Estland) was Reval (Tallinn), founded at the place of Lyndanisse after the invasion of 1219. The Danes built the fortress of Castrum Danorum at Toompea Hill. Estonians still call their capital "Tallinn", which according to legend derives from Taani linna (meaning Danish town or castle). Reval was granted Lübeck city rights (1248) and joined the Hanseatic League. Even today, Danish influence can be seen in heraldic symbols. The Danish cross is on the city of Tallinn's coat of arms, and Estonia's coat of arms displays three lions similar to those found on the Danish coat of arms.
What structure was built at Toompea Hill?
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Answer: the fortress of Castrum Danorum


Problem: During the 19th and 20th centuries there was a major dispute known as the Greek language question, on whether the official language of Greece should be the archaic Katharevousa, created in the 19th century and used as the state and scholarly language, or the Dimotiki, the form of the Greek language which evolved naturally from Byzantine Greek and was the language of the people. The dispute was finally resolved in 1976, when Dimotiki was made the only official variation of the Greek language, and Katharevousa fell to disuse.
Which language was considered the language of the people?
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Answer:
Dimotiki