On this week’s show: Researchers try to identify effective loneliness interventions, making the Sandmeyer safer, and books that look to the future and don’t see doom and gloom

A different source of global warming, signs of a continentwide tradition of human sacrifice, and a virus that attacks the cholera bacteria

Researchers are testing HIV drugs and monoclonal antibodies against long-lasting COVID-19, and what it takes to turn a symbiotic friend into an organelle

Tracing the arrival of rats using bones, isotopes, and a few shipwrecks; and what scientists have learned in 50 years about our famous ancestor Lucy

Robots that can smile in synchrony with people, and what ends up in the letters section

New clinical trials for treatments of an always fatal brain disease, and what happens with pests when a conventional and organic farm are neighbors

On this weeks show: Investigating infantile amnesia, and how generalized fear after acute stress reflects changes in the brain

What modern Indian genomes say about the regions deep past, and how vitamin A influences stem cell plasticity

Keeping water out of the stratosphere could be a low-risk geoengineering approach, and using magnets to drive medical robots inside the body

On this weeks show: Factors that pushed snakes to evolve so many different habitats and lifestyles, and news from the AAAS annual meeting