Everything we now know about the universe - from the behavior of quarks to the birth of galaxies - has come from people who've been willing to ponder the unanswerable. And with the advent of modern science, great minds have turned to testing and experimentation rather than mere thought as a way of grappling with some of the universe's most vexing dilemmas. So what is our latest picture of some of the most inexplicable features of the universe? What still remains to be uncovered and explored by today's scientists? "We know a lot about the universe. But there's even more that we don't know," says astrophysicist and professor Neil deGrasse Tyson, director of the Hayden Planetarium, an award-winning lecturer, and one of the world's foremost experts on the secrets of the universe. This course, which has been honored with a 2013 Telly Award for Outstanding Educational Program, features six self-contained lectures that transport you on a marvelous journey to the frontiers of the known...