New York's 92nd Street Y and msnbc have gathered 16 world shakers—from the profound to the popular, from scientists to celebrities—and placed them head-to-head in one very varied bracket. Genius indeed takes many forms, and which kind will triumph comes down to you. Who’s the Ultimate Genius? Cast your vote now!

Voting Schedule
Round 1: Feb 9 to Feb 15
Round 2: Feb 16 to Feb 22
Semi-finals: Feb 23 to Mar 1
Finals: Mar 2 to Mar 8

The ultimate genius showdown: you decide