We know about our universe's past: the Big Bang theory predicts that all matter, time and space began about 14 billion years ago. And we know about the present: scientists' observations of galaxies tell us that the universe is expanding at an accelerated rate. But what about the future? Do we know how our universe is going to end? Venus Keus exp...

Every time you breathe, air travels down the trachea, through a series of channels, and then reaches little clusters of air sacs in the lungs. These tiny sacs facilitate a crucial exchange: allowing oxygen from the air we breathe into the bloodstream and clearing out carbon dioxide. Pneumonia wreaks havoc on this exchange system. Eve Gaus and Va...