Scientists have helped to construct a detailed timeline for bacterial evolution, suggesting some bacteria used oxygen long before evolving the ability to produce it through photosynthesis. University ...

At head of title: DK Smithsonian. "The ultimate visual guide to the discoveries that shaped the world"--Cover. Before science began (2.5 MYA -- 799 C.E.) : Early metallurgy ; The story of the wheel ; ...

"Written by Megan Roth"--Back cover. Consists of 1 volume of text and 1 box containing parts for a 6-inch rocket model and a double-sided poster, bound together with a standard hardcover. Text volume ...

Have you ever made a mistake that you wish you could undo? Correcting past mistakes is one of the reasons we find the concept of time travel so fascinating. As often portrayed in science fiction, with ...