1) In Norse mythology, Ragnarok is a cataclysmic event that signifies the end of the world. It involves a series of apocalyptic battles and natural disasters, leading to the destruction of the gods and the world as it is known. From the ashes, a new world and a new generation of gods emerge.

2) The world's oldest living plant is believed to be a clonal shrub called "Old Tjikko" in Sweden, estimated to be over 9,500 years old.

3) Banks play a vital role in the economy by facilitating the flow of funds between savers and borrowers, providing loans, and offering various financial services.

4) The Black Lives Matter movement gained renewed momentum in 2020 following the killings of George Floyd, Breonna Taylor, and others, sparking protests and discussions on systemic racism, police reform, and social justice around the world.