Alan Alda joins some of the world's leading astronomers as they wrestle with the implications of their latest discoveries: that everything we can see, from the world around us to the most distant galaxies, is only a tiny fraction of the entire cosmos. watch
Alan Alda joins some of the world's leading astronomers as they wrestle with the startling implications of their latest discoveries: that everything we can see, from the world around us to the most distant galaxies, is only a tiny fraction of the entire cosmos. Most of what's out there is dark -- either dark matter or dark energy. And our universe is perhaps only one in an infinity of universes. watch