Today’s marvel of technology comes courtesy of New Scientist magazine: a solution to the age-old problem of unopened pistachio nuts. In every handful of pistachio nuts there are a few whose shells are completely closed, indicating they’re unripe and unopenable anyway. Mechanical pickers try to separate out the open-shelled nuts, but some that are closed invariably make their way into the pile.
But this is a country built on great ideas, and along comes the next one: separating the two types of nuts by sound. Tom Pearson, an engineer at the U.S. Agricultural Research Service in Manhattan, Kansas, has developed a sound-based sorter after noticing that closed nuts sound differently when they’re dropped than do open nuts. He is able to drop 25 nuts a second and differentiate the open from the closed, using a wisp of air to keep the closed nuts from the good pile. His method is 97% efficient, versus 90% for the mechanical pickers–a difference that could save at least one company a half million dollars a year.
It’s a wonderful world, nuts and all.