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

2) The concept of quantum computing explores the use of quantum mechanics principles to perform complex computations, potentially revolutionizing fields such as cryptography and optimization.

3) The national animal of Australia is the kangaroo.

4) The Berlin Conference in 1884-1885 divided Africa among European powers and set the stage for the colonization of the continent.