Usually, to keep things cold, we use electric refrigerators. But did you know that you can keep things cold without using electricity? An inventor in Nigeria named Mohammed Bah Abba designed a solution to help local farmers keep their vegetables and fruits cold. In his village, the farmers don't have access to electricity. Without refrigeration, food will spoil after just a day or two. This means that farmers don't have very much time to harvest and then sell their foods, and the people buying the foods have to eat it right away. But Mohammed came up with a simple and low-tech design that would give farmers many more days to sell their harvests. He placed a smaller pot inside a larger pot and packed wet mud in between the two pots. He filled the smaller inner pot with food, and he covered the food with a wet cloth. As the water in the mud evaporated and dried out, the temperature of the mud dropped to 40 degrees. That's the same as the temperature of an electric refrigerator!
With his design, Mohammed was able to help people keep food fresh for much longer, without needing electricity. This means that foods are easier to find and cheaper!
Click here to learn more about these low-tech refrigerators!
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(Image credit: National Geographic)