One barrel of petroleum holds 42 gallons.
20
The weight of a carat (200 milligrams), standard unit of measurement for gemstones, is based on the weight of the carob seed.
51
In Arizona, a solar wind energy tower has been proposed that would generate as much energy as the Hoover Dam.
5
The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
There are more than 270 people cryogenically frozen in the hope that one day the technology will exist that can revive them and extend their lives.
13
Indoor pollution is 10 times more toxic than outdoor pollution.
62
A single speck of dust is half way in size between a subatomic particle and the Earth.
15
The gas that gives rotten eggs their distinctive foul smell may slow ageing and block damaging chemical reactions inside cells, according to scientists in China.
5