There Are Now Eight Billion People On Earth. What’s Next? Humankind just hit a big milestone this week: a world population of eight billion people. A hundred years ago, there were less than two billion, and now we’ve more than quadrupled that. But after decades of quick population growth, what will the next few decades hold? Sophie Bushwick, technology editor at Scientific American, explains this to Ira live from the studio. They also talk about other science news this week, like a new initiative from COP 27 to help transition poor countries away from fossil fuels, an ambitious plan to put solar panels in space, how mental health apps aren’t protecting user data, what the discovery of the earliest cooked meal in history tells us about human evolution, and the very first lab-grown meat to gain FDA approval.   Groundwater Contamination In Springfield, Missouri Kept Secret From Residents Early in 2019, Ed Galbraith faced a crowd of some 200 unhappy Springfield, Missouri residents. He wanted to make amends. Galbraith, then director of Missouri Department of Natural Resources’ environmental quality division, acknowledged that the state agency in charge of protecting the environment should have announced sooner that contaminated water had spread from an old industrial site near the Springfield-Branson National Airport. Residents had recently found out that a harmful chemical known to cause cancer had been detected in the groundwater. The contamination came from the site of the now-shuttered Litton Systems, a former defense contractor that had employed thousands of people in Springfield to make circuit boards for the Navy and telecommunications industry. Read the rest at sciencefriday.com.   Can A New Surge Of Tech Interest Make The Metaverse A Thing? Late last year, Mark Zuckerberg took the company then known as Facebook in a new direction. He renamed it Meta, short for “metaverse.” And he promised the company would go all in on building a virtual reality world like the first famous metaverse—the fictional topic of Neal Stephenson’s 1992 novel “Snow Crash.” While many companies have tried to make metaverses in the 30 years since “Snow Crash” came out, including the popular virtual world called Second Life, we seem to be entering a new era of metaverse hype: besides Zuckerberg, Apple seems to be investing in a VR world. And even Nike wants to make a metaverse. So what are users actually getting if these companies succeed at their goals? And are there other, perhaps better, ways to go about bringing people together virtually? Ira talks to science fiction writer and tech journalist Annalee Newitz, and Avi Bar-Zeev, a pioneer of extended-reality technologies for companies like Disney, Apple, and others. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.