The Biggest Ideas in the Universe is a series of videos where I talk informally about some of the fundamental concepts that help us understand our natural world. Exceedingly casual, not overly polished, and meant for absolutely everybody. This is Idea #14, "Symmetry." Different manifestations of symmetry are at the heart of much of modern physics, so it's worth looking at how we should best characterize it. That's leads us into the mathematics of group theory. My web page: http://www.preposterousuniverse.com/ My YouTube channel: https://www.youtube.com/c/seancarroll Mindscape podcast: http://www.preposterousuniverse.com/podcast The Biggest Ideas playlist: https://www.youtube.com/playlist?list=PLrxfgDEc2NxZJcWcrxH3jyjUUrJlnoyzX Blog posts for the series: http://www.preposterousuniverse.com/blog/category/biggest-ideas-in-the-universe/ Background image by Sylvia Cordedda at DeviantArt: https://www.deviantart.com/c-91/art/Naive-341640491 #science #physics #ideas #universe #learning #cosmology #philosophy #math #grouptheory #symmetry