Astronomers have been able to detect supermassive black holes and teeny-weeny black holes but the midsize ones have been elusive. Now, researchers have scanned through archives looking for middle-size galaxies and found traces of these missing middlers. Host Sarah Crespi and Staff Writer Daniel Clery discuss why they were so hard to find in the first place, and what it means for our understanding of black hole formation.

Farming animals and plants for human consumption is a massive operation with a big effect on the planet. A new research project that calculated the environmental impact of global food production shows highly variable results for different foods—and for the same foods grown in different locations. Sarah talks with one of the researchers—Joseph Poore of the University of Oxford in the United Kingdom—about how understanding this diversity can help cut down food production’s environmental footprint and help consumers make better choices.

This week’s episode was edited by Podigy.

Listen to previous podcasts.

[Image: Miltos Gikas/Flickr; Music: Jeffrey Cook]