How much skin covers the human body?
The average body has 14 to 18 square feet of skin.
The light from a firefly comes from an area on the sides of its stomach. Fatty tissue located there contains air tubes and nerves that when stimulated give off oxygen. The oxygen combines with a pigment in the fat called luciferin, producing the familiar heatless light.
As of 1990, 53 percent of Americans drink fluoridated water. Of these, 121 million drink artificially fluoridated water; 9 million drink water from naturally fluoridated sources.
There are 10 types of clouds: cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, stratocumulus, stratus, cumulus, cumulonimbus. Each of these clouds has a different shape and internal structure.
The sensation, called neurapraxia, usually occurs when a nerve is compressed between a bone and another hard object. Blood continues to circulate through the affected area.
Yes, at least since 1800. At that time, Philadelphia and Baltimore were the second and third-largest cities. Census estimates for 1986 placed Los Angeles and Chicago, respectively, in those ranks.
First used in 1940 by nine-year-old Milton Sirotta, the number googol is the number 1 followed by 100 zeros. It was brought to public attention by Sirotta’s uncle, mathematician Edward Kasner, in his book Mathematics and the Imagination.