Bubble enthusiasts know that much of the secret to a bubble's iridescent success lies in the soapy mixture they're made from. There's a whole wiki page devoted to finding the perfect formula. And now that a team of physicists has looked at bubble formation in the lab, there’s a better explanation for what allows thin, sudsy films to expand.
Besides soap, many bubble-blowers also use additives called long-chain polymers — or long molecules similar to what's used in plastics — in their solution. The research found that, when added to bubble solution, these polymers stretch and let large bubbles expand, especially when they come in a variety of lengths.