Cryogenics is the study of production and behavior of materials at extremely cold temperatures. It began in the 19th century with scientists liquefying gases. Today, cryogenics has applications like MRI, superconducting cables for power transmission, blood banking, rocket engines using cryogenic fuels, and food freezing. Cryogenics enables sensitive detectors for astronomy and enables cooling electronics to reduce noise. Cryogenic processing improves materials by making them more durable through deep freezing over long periods.