Bill Nye the Science Guy was an American educational television series that first aired in 1993, with Bill Nye presenting science concepts through demonstrations, sketches and humor aimed at children. Its opening theme became closely tied to that classroom-friendly format, and clips of it later circulated widely on YouTube and social media as nostalgia for the show grew. Today creators reuse the intro to signal a science-themed joke, an experiment or a mock lesson, because most viewers recognize it instantly even if they have not watched the original series in years.