The Earth's atmosphere weighs about 5.5 quadrillion tons.
108
Indoor pollution is 10 times more toxic than outdoor pollution.
62
Hot water can freeze faster than cold water.
181
The average temperature at 40,000 feet above sea level is -60 F.
56
4.5 pounds of sunlight strike the Earth each day.
27
Scientists have revived a flowering plant from a fruit stored away in permafrost by Arctic ground squirrel 32,000 years ago.
16
German chemists made a replica of a trophy the size of one molecule.
68
MIT has developed a camera that captures the speed of light at a trillion frames per second.
20