Refrigeration is any of various types of cooling of a space, substance, or system to lower and/or maintain its temperature below the ambient one. Refrigeration is an artificial, or human-made, cooling method.
Commercial refrigeration
Ice harvesting in Massachusetts, 1852, showing the railroad line in the background, used to transport the ice.
William Cullen, the first to conduct experiments into artificial refrigeration.
Ferdinand Carré's ice-making device
Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.
An ice block, photographed at the Duluth Canal Park in Minnesota
This iceberg can stay afloat in spite of its size because it is less dense than water
So-called feather ice on the plateau near Alta, Norway. The crystals form at temperatures below −30 °C (−22 °F) and contain a lot of trapped air, making them light enough to be supported by the thin branch
Frozen waterfall in southeast New York
