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 #12, "Scale." For something more down-to-Earth than the last couple of lectures, we think about why things have the size they do. This is a rich topic so we don't get very far into it, we'll have to return later! 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: https://www.wallpaperflare.com/blue-and-gold-digital-wallpaper-ball-shape-line-plexus-pattern-wallpaper-phve #science #physics #ideas #universe #learning #cosmology #philosophy #quantum #scaling