Zoos are becoming facsimiles - or perhaps caricatures - of how animals once were in their natural habitat. If the right policies toward nature were pursued, we would need no zoos at all.
In 1687, Newton published Philosophae Naturalis Principia Mathematica, what is widely regarded to be one of the important books in the history of science. In it he describes universal gravitation and the three laws of motion, concepts that remained at the forefront of science for centuries after.
