Leonardo DaVinci noted that when trees branch, smaller branches have a precise, mathematical relationship to the branch they sprang from. iStockphoto.com hide caption

itoggle caption iStockphoto.com

Dr. Alfredo Quiñones-Hinojosa picked tomatoes, shoveled sulfur and scraped fish lard before becoming one of America's most respected neurosurgeons. Keith Weller hide caption

itoggle caption Keith Weller