The Earth's interior is composed of four layers ... sped up, or delayed by the various layers.

The origin of life on Earth stands as one of the great mysteries of science. Various answers have been proposed, all of which remain unverified. To find out if we are alone in the galaxy, we will need ...

On a much larger scale, solar-thermal power plants employ various techniques to concentrate ... Every hour the sun beams more energy onto Earth than it needs to satisfy global energy needs for ...