This week we're looking at astrophysics, zooming out to get a better idea of how universe works and what it might look like. Astrophysicist Ethan Siegel returns to talk about his new -- and first -- book "Beyond the Galaxy: How Humanity Looked Beyond Our Milky Way and Discovered the Entire Universe". And we'll speak with astrophysicist Katie Mack about the discovery of gravity waves, first predicted by Einstein. This episode is partially hosted by Bethany Brookshire, science writer from Science News. If you're looking for more on gravity waves, check out this great explainer article and video on Science...