It’s the start to a holiday weekend, which often means spending time outdoors, whether that’s going to the beach, on a hike, or grilling in a park. But not everyone feels safe enjoying the great outdoors—and we’re not talking about getting mosquito bites or sunburns. In late May, a white woman, Amy Cooper, called the police on a Black bird watcher who asked her to leash her dog. This incident felt familiar to many other Black outdoor enthusiasts, many of whom had encountered similar experiences of racism outside. To understand why the outdoors is an unwelcoming place for some people, we need to look back at our violent history. Joining Ira to talk about this is Dr. Carolyn Finney, author of the book Black Faces, White Spaces. She is also a scholar-in-residence at Middlebury College in Vermont. And later in the conversation, Ira is joined by two scientists, biology graduate student Corina Newsome from Statesboro, Georgia, and exploration geoscientist Tim Shin from Houston, Texas. They’ll talk about what it’s like to do fieldwork while Black, and what responsibility academic institutions should have in keeping their students safe.   As coronavirus cases surge across the U.S., including in Texas, Florida, Arizona, and California, it’s more important than ever to have an accurate and real-time understanding of transmission. Epidemiologists have been measuring the spread of the virus based on the number of individual people who test positive. But depending on when people get tested, and how long it takes to get their results, confirmed cases can lag days behind actual infections. Luckily, there’s another way to find out where people are getting sick: The virus that causes COVID-19 can be detected in feces, and for months, researchers have been studying whether sampling sewage systems can help identify new outbreaks faster. Scientific American technology editor Sophie Bushwick joins Ira to talk about the value of sewage tracing for COVID-19. Plus, a new sparrow song has gone viral in Canada, and why summer fireworks can damage not only your hearing, but also your lungs.