1) The word "triangle" contains four vowels: I, A, E, and E.

2) The shortest war in history lasted only 38 to 45 minutes between Britain and Zanzibar in 1896.

3) The first commercial mobile phone, the Motorola DynaTAC 8000X, was released in 1983 and weighed nearly 2 pounds.

4) In Norse mythology, Valhalla is a majestic hall located in Asgard, the realm of the gods. It is the afterlife destination for brave warriors who die in battle, where they are greeted by the Valkyries and engage in feasting, drinking, and preparing for the final battle of Ragnarok.