1) The discovery of the Americas by Christopher Columbus in 1492 opened up new trade routes and had a profound impact on world history.

2) The first computer mouse was invented by Douglas Engelbart in 1964 and consisted of a wooden shell and two metal wheels.

3) DNA, the building block of life, can store incredible amounts of data. It is estimated that one gram of DNA could potentially store about 215 petabytes of data.

4) 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.