Jupiter
Jupiter is the largest planet in our solar system. One of the "gas giants," the ...
Before the invention of mechanical refrigeration systems, the only practical method for preventing food spoilage was keeping it cold with ice or snow. In prehistoric times, people would bury extra game and other perishable food in the snow to keep it cold. Later, they dug pits in the ground, lined them with wood and straw, and filled them with snow. The ancient Chinese harvested ice from frozen lakes to use for refrigeration. The "icebox" was the nineteenth-century equivalent of today's refrigerator. It was designed to hold a large chunk of ice and a family's perishable food. The ice had to be replaced daily. Ice was harvested in the winter from frozen lakes and stored in insulated icehouses. By the 1890s, usable natural ice became increasingly scarce in America due to the pollution of lakes and rivers. Iceboxes were cooled by commercially produced blocks of ice until the 1930s, when most Americans began switching to refrigerators.
You might think mummies are only for Halloween, but mummies actually do exist. A mummy is ...
It is important to protect ourselves from the sun's strong rays. But scientists say th...