Resolving the dispute over the speed of the expanding universe, and seeking new drug targets for cognitive dysfunction

This episode of the Science Magazine Podcast explores two groundbreaking scientific developments. First, it examines the persistent 'Hubble tension'—the discrepancy between two methods of measuring the universe's expansion rate. Astronomers using standard candles (like Cepheid variables and Type Ia supernovae) calculate a Hubble constant of about 73 km/s per megaparsec, while cosmologists using the cosmic microwave background arrive at 67 km/s per megaparsec. The episode introduces gravitational lensing as a promising third method: by observing time-delayed images of lensed supernovae, scientists can triangulate distances independently of prior assumptions. Though current data is still uncertain, upcoming telescopes like the Vera Rubin Observatory are expected to increase the number of observable lensed supernovae, potentially resolving the tension and shedding light on dark energy. The second segment features neuroscientist Mauro Costa-Mattioli discussing the integrated stress response (ISR) in the brain. His research shows that a hyperactive ISR—triggered by genetic mutations or disease—impairs memory formation by suppressing protein synthesis. Using a viral protein from African swine fever, which naturally inhibits the ISR, his team reversed cognitive deficits in mouse models of Alzheimer’s, Down syndrome, and aging. This suggests a 'disease-agnostic' therapeutic strategy targeting a common cellular pathway underlying diverse cognitive disorders. The episode underscores the power of interdisciplinary approaches in both cosmology and neuroscience.