#11: Scientist of the 
Arab Spring

When Ahmed Zewail first heard of the popular revolt against Egyptian president Hosni Mubarak on January 25, 2011, he immediately left for Cairo. “It was a very emotional time. I have family in Egypt, and I owe the country my early education,” says Zewail, who is a professor of chemistry at Caltech. “I knew I had to take action.”