1680s introductions

The balalaika (, ) is a Russian stringed musical instrument with a characteristic triangular wooden, hollow body, fretted neck, and three strings. Two strings are usually tuned to the same note and the third string is a perfect fourth higher. The higher-pitched balalaikas are used to play melodies and chords. The instrument generally has a short sustain, necessitating rapid strumming or plucking when it is used to play melodies. Balalaikas are often used for Russian folk music and dancing.

folkloric figure and symbol of Easter

abugida used for Mongolian

philosophical thought experiment: “if a man born blind, who can feel the differences between shapes, is given the ability to see, could he distinguish those objects by sight?”

Theorem in classical mechanics