Is the world ending? Is civilization collapsing? How have some scientists studied the nature of hope, despair, and doom?  One scientist builds a utopia for mice and rats to see how long it might take for their civilization to collapse under its own weight. Another scientist drops rats in tanks of water to study the effects of fear. We take a look at these experiments and speak to evolutionary biologist Bret Weinstein to understand whether or not the fate of the rat utopias might predict the collapse of our own civilization.  Learn more about your ad choices. Visit megaphone.fm/adchoices