A zap from a doorknob or a lightning bolt that sets fire to a forest, these events are notoriously unpredictable. If there is an imbalance of electric charge, a Static Electricity event "might" happen. Things like air humidity or microscopic superficial bumps can play a role – but how much? Professor Lewis explains the known physics and yet-to-be discovered secret life of static electricity with Dr Karl. drkarl.com geraintflewis.com