As the year comes to a close, we review the best science, the best stories, and the best books from 2019. Our end-of-the-year episode kicks off with Host Sarah Crespi and Online News Editor David Grimm talking about the top online stories on things like human self-domestication, the “wood wide web,” and more.
News Editor Tim Appenzeller joins Sarah to discuss Science’s 2019 Breakthrough of the Year, some of the contenders for breakthrough, also known as runners-up, and a breakdown—when science and politics just didn’t seem to mix this year.
Finally, Science books editor Valerie Thompson brings her favorites from the world of science-inflected media. She and Sarah talk about some of the best books reviewed in Science this year, a food extinction book we should have reviewed, a pair of science-centric films, and even an award-winning birding board game.
During this decade, as in previous decades, Caltech scientists and engineers reinvented the landscape of scientific endeavor: from the first detection of gravitational waves and the discovery of evidence for a ninth planet in the solar system; to bold missions to explore and understand the solar system; to the development of new methods to see inside the body and the brain and understand the universe around us; to the invention of devices to improve human health, some taking inspiration from nature; to the initiation of a transformative new effort to support research into the most pressing challenges in environmental sustainability.
Though the brain orchestrates how we experience the world, many questions remain about its complex workings. During the past 10 years, Caltech scientists have discovered how the brain recognizes
As modern technology advances, so do the possibilities for treating medical conditions that were previously considered untreatable. Caltech researchers used an electrode array to help a paralyzed patient
In our own study of more than 7,000 middle-aged to older adults in the U.K., published in 2019 in Brain Imaging and Behavior, we demonstrated that people who spent more time engaged in moderate to vigorous physical activity had larger hippocampal volumes. Although it is not yet possible to say whether these effects in humans are related to neurogenesis or other forms of brain plasticity, such as increasing connections among existing neurons, together the results clearly indicate that exercise can benefit the brain’s hippocampus and its cognitive functions.
Listen to an audio version of our feature article by Amber Dance. Research groups around the world are exploring new ways of protecting coral reefs from climate change.

About one-third of people with epilepsy are treatment resistant. Up until now, epilepsy treatments have focused on taming seizures rather than the source of the disease and for good reason—so many roads lead to epilepsy: traumatic brain injury, extreme fever and infection, and genetic disorders, to name a few. Staff Writer Jennifer Couzin-Frankel talks with host Sarah Crespi about researchers that are