The atmosphere has not always been the same. It has been much the same, but nevertheless now contains more nitrogen and oxygen, and less carbon dioxide, than it did when the earth first formed. Recently, the addition of greenhouse gases...

College-level online course highlighting the fundamentals of ecology. Course topics include coevolution of the biosphere, geosphere, atmosphere, and hydrosphere; photosynthesis and respiration; and the carbon, nitrogen, and water cycles....

This site from The Eight Planets shows that Titan may serve as a model of a highly reduced early Earth atmosphere in which the first stages of organic chemical evolution could take place in the atmosphere.

Describes the evolution of Thomas Newcomen's steam engine development. Provides several photographs and sketches of Newcomen's machines.

No scientific phenomena concern us as much as the daily evolution of weather systems. We live in a culture where weather, the state of the atmosphere at a given time and place,helps us define regional cultural variations. States such as...

Situated on the island of Tenerife, Teide National Park features the Teide-Pico Viejo stratovolcano that, at 3,718 m, is the highest peak on Spanish soil. Rising 7,500 m above the ocean floor, it is regarded as the world’s third-tallest...