1) The fastest recorded serve in tennis was achieved by Sam Groth at 163.7 miles per hour (263.4 kilometers per hour) during a tournament in 2012.

2) The Olympic motto is "Citius, Altius, Fortius," which is Latin for "Faster, Higher, Stronger."

3) Celtic mythology encompasses the folklore and legends of the Celtic peoples across Europe, particularly in regions like Ireland, Scotland, and Wales. It features deities like Morrigan, Cernunnos, and Brigid, and delves into themes of nature, magic, and the heroic exploits of legendary figures like Cu Chulainn.

4) The process of photosynthesis, performed by plants, algae, and some bacteria, is responsible for producing the oxygen we breathe.