On this week’s show: Geoscientists eye contenders for where to mark the beginning of the human-dominated geological epoch, and how sunscreen turns into photo toxin We live in the Anthropocene: an era on our planet that is dominated by human activity to such an extent that the evidence is omnipresent in the soil, air, and even water. But how do we mark the start? Science Staff Writer Paul Voosen talks with host Sarah Crespi about how geoscientists are choosing the one place on Earth that best shows the advent of the Anthropocene, the so-called “golden spike.”   Also this week, Djordje Vuckovic, a Ph.D. candidate in the department of civil and environmental engineering at Stanford University, joins Sarah to talk about how sunscreen threatens coral reefs. Reefs are under a lot of stress these days, from things like warming waters, habitat destruction, and the loss of their fishy friends to voracious fishermen. Another suspected stressor is chemical sunscreens, which drift off swimming tourists. It turns out that common chemicals in sunscreen that protect skin from the Sun are modified by sea anemones and corals into a photo toxin that damages them when exposed to the Sun’s rays.   This week’s episode was produced with help from Podigy.   [Image: Amanda Tinoco; Music: Jeffrey Cook]   [alt: photo of healthy corals at the Great Barrier Reef in Australia with podcast symbol overlay]   Authors: Sarah Crespi; Paul Voosen   TWEET New @ScienceMagazine Podcast: @voooos Djordje Vuckovic @cee_stanford https://www.science.org/doi/10.1126/science.abq8294   This week on the @ScienceMagazine Podcast, reporter @voooos   https://www.science.org/doi/10.1126/science.abq8294         ++ LINKS FOR MP3 META   Episode page: https://www.science.org/doi/10.1126/science.abq8294   About the Science Podcast: https://www.science.org/content/page/about-science-podcast                   Learn more about your ad choices. Visit megaphone.fm/adchoices