Perhaps one positive will come out of the fiery disaster that took down the World Trade Center buildings. The horrific incident inspired researchers at the California Institute of Technology (Caltech) in Pasadena to look for ways to make transportation fuels less explosive. Gasoline, kerosene, and other transportation fuels are composed of highly flammable hydrocarbons—typically 5 to 14 carbon atoms in length. During an impact, these short hydrocarbons readily form a cloud of tiny fuel droplets that can ignite, producing a fireball. Fuel researchers have long known that much longer hydrocarbon chains can interact with fuel molecules, causing them to form larger droplets during an accident. These larger droplets don’t linger as long in the air, so there is less chance for a catastrophic explosion. But earlier efforts to incorporate these long molecules into fuels brought other problems. They often got tangled in themselves, clogged fuel pumps, and often broke apart, reducing their ability to suppress fires. But now, the Caltech scientists report in Science that by linking together shorter molecules with sticky ends, the resulting “mega-supramolecule” can remain in one long chain. This huge polymer breaks apart under stress, leaving the fuel pump clog-free. It can also use its sticky ends to reassemble and restore its flame-suppressing activity. Most important, the new additives ensure the formation of larger droplets during an impact, warding off violent explosions (as shown in the video above). Future Fast and Furious movies should note—this fuel additive is not for you.