The Norse dwarves are highly significant entities within Norse mythology. They are the makers of most of the artefacts of the gods, both Aesir and Vanir. Their dwelling places are two of the nine worlds upon the world-ash Yggdrasil, that of Nidavellir and of Svartalfheim.
They are known also as svartalfir, or "dark elves".
... between the axis and the groove rims will accelerate or brake the spinning gyroscope, with a maximum effect when the axis starts "rolling" inside the groove. (Compare with ...