BLUE WHIRL A swirling flame called a blue whirl is produced in the lab by igniting fuel floating on top of water (left). The flame first transitions into a 60-centimeter-tall fire tornado (center) before settling down into a quietly spinning blue flame (right) just 6 centimeters in height.
H. Xio, M.J. Gollner, E.S. Oran/PNAS 2016