Here is one of the great existential problems that caused a lot of 20th century angst: the more we learn about the universe, the more we realize how insignificant we are. Here is 21st century science's answer to that: Humans are very sophisticated conglomerates of materials. We are very special indeed. Dartmouth professor Marcelo Gleiser walks us through some of the key milestones in our understanding of the universe.

– Big Think
November 21, 2012