1) The world's largest flower is the Rafflesia arnoldii, which can grow up to 3 feet (1 meter) in diameter and weighs about 15 pounds (7 kilograms).

2) The Civil Rights Act of 1964 in the United States outlawed discrimination based on race, color, religion, sex, or national origin.

3) The development of the microprocessor by Intel in 1971 paved the way for the modern computer and led to the exponential growth of computing power.

4) In Norse mythology, the Valkyries are divine maidens who serve Odin, the chief god. They are responsible for selecting warriors worthy of entering Valhalla and escorting them to the afterlife. They are often depicted as powerful and beautiful figures, riding winged horses and wielding spears.