Mark Zuckerberg is an American media magnate and internet entrepreneur born on this day in 1984, best known for co-founding the social media website Facebook.

Did you know that:

• Adolphe Nicole patented the chronograph on this day in 1862
• George Lucas is an American film director, producer, and screenwriter born on this day in 1944
• Miranda Cosgrove is an American actress and singer born on this day in 1993