1) The Dow Jones Industrial Average (DJIA) is a stock market index that tracks the performance of 30 large, publicly owned companies in the United States.

2) Mount Everest, located in the Himalayas, is the highest mountain on Earth, reaching a peak elevation of 29,032 feet (8,848 meters).

3) The world's oldest tree is believed to be a bristlecone pine named "Methuselah" in California, estimated to be over 4,800 years old.

4) The first successful consumer digital camera, the Apple QuickTake 100, was released in 1994 and had a resolution of 640 x 480 pixels.