In the quest to understand our world and the universe in which it sits, Marcelo Gleiser advises: "Not all questions have answers. To hope that science will answer all questions is to want to shrink the human spirit, clip its wings, rob it from its multifaceted existence." Goddard/Arizona State University/NASA hide caption

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Could North Korea be behind commentator Alva Noë's car problems? Not likely. Just as it's not likely a theory of everything will ever explain human behavior. Ed Jones/AFP/Getty Images hide caption

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We think that life came from non-life, from the increasing complexity of chemical reactions between biomolecules present on the primordial Earth. But what about the universe? How did it come to be if there was nothing before? iStockphoto hide caption

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Is science more like a pyramid, or a sun-dappled patch of ground? Fayez Nureldine/AFP/Getty Images hide caption

itoggle caption Fayez Nureldine/AFP/Getty Images