There are many possible explanations for hauntings, not least that humans are highly suggestible creatures, especially when we want to believe. But some ghost sightings might actually be the result of sounds — sound waves that vibrate just below our range of hearing, dubbed the “fear frequency.”
Vi Hart, the soothing voice behind stop motion science-y explanations, is back at it again. In her latest video, she's showing you sound. Yup, she draws, annotates, illustrates, plays notes and visualizes every little nit and grit there is to know.