When Scott Waitukaitis set out to understand a puzzling aspect of static electricity, he didn’t expect to find the answer in a substance colloquially known as “schmutz”. But after a painstaking series of experiments, Waitukaitis and colleagues at the Institute of Science and Technology Austria (ISTA) have strong evidence that carbon-based surface contaminants – in other words, schmutz – are, in fact, the determining factor in how electric charge flows when certain types of insulating materials come into contact. By clearing up this mystery, the ISTA scientists say that their findings, which are published today in *Nature, *could shed fresh light on phenomena such as lightning and protoplanetary disk formation where static electricity plays a significant role. If you’ve ever felt a shock after rubbing your hair with a balloon or shuffling across a carpet, you’ll know that static electricity can be a real pain. But for the scientists who study it, the pain runs much deeper.…