Olympic gold medalist Florence "Flo-Jo" Griffith Joyner died 25 years ago on Sept. 21, 1998. The sprinter's world records for the 100 meter and 200 meter events remain unbroken.

On June 18, 1983, she made history aboard the space shuttle. America's first woman in space had joined NASA after responding to a newspaper ad. "I knew that's what I wanted to do," she said.

On June 5, 1968, Sen. Robert F. Kennedy was gunned down in a hotel in Los Angeles. Kennedy, a presidential hopeful who was memorialized as a liberal icon, was complicated and contradictory.

AI is changing our lives – from education and politics to art and healthcare. But what is AI? Should we be optimistic or worried about our future with this rapidly developing technology?