1) The world's largest diamond, the Cullinan, was discovered in South Africa in 1905 and weighed over 3,000 carats.

2) Rihanna, born Robyn Rihanna Fenty, is a Barbadian singer, actress, and businesswoman. She has achieved great success in the music industry with hits like "Umbrella," "Diamonds," and "Work," and has also ventured into the worlds of fashion and cosmetics with her brands.

3) The first consumer digital video recorder (DVR), the TiVo, was introduced in 1999 and allowed users to record and store television programs for later viewing.

4) The American Civil Rights Movement, led by figures like Martin Luther King Jr., fought for equal rights and helped bring about significant social and legislative changes.