Plank's son Roger, 42, who serves as chief financial officer, keeps a reminder of those days on his desk: asmall vial of foul-looking water with a thin layer of crude oil on the top.
Salman Khan (the educator, not the Bollywood actor) is changing the very foundation of how eduction is delivered between a teacher and student, from his smalldesk in his home, without a PhD or years serving in academia.