1) The name "Bluetooth" comes from the 10th-century Danish king, Harald Bluetooth, who united Denmark and Norway.

2) The world's oldest known recipe is for beer and is over 4,000 years old.

3) The Black Lives Matter movement, which gained prominence in 2013, advocates for racial justice and equality, addressing systemic racism and police violence against Black individuals.

4) The Renaissance period, which began in Italy in the 14th century, marked a renewed interest in art, literature, science, and philosophy.