An early study found that electrical stimulation could improve hand and arm function in people with spinal cord injuries. Also, for thousands of years, Indigenous communities in Guatemala have used observations and mathematics to track astronomical events.Zapping Nerves Into RegrowthResults of an early trial published this week in the journal Nature Medicine found that people with cervical spinal cord damage showed some improvements both in strength and movement in arm and hand function after they received electrical stimulation near the site of their injury. The improved function persisted even after the stimulation stopped, indicating that the treatment may be inducing nerve cells to regrow in the damaged area.Sophie Bushwick, senior news editor at New Scientist, joins Ira to talk about the work and what it could mean for people with severe spinal cord injuries. They also talk about other stories from the week in science, including creating the most powerful X-ray pulse ever reported, investigations into the microbiome of the scalp, and some epic cosplay—testing out the practicality of some ancient Greek armor in combat scenarios.Celebrating the Maya Calendar In Guatemala’s HighlandsEvery 260 days, Indigenous communities in the highlands of Guatemala celebrate a new cycle of the Maya calendar. This ceremony has persisted for thousands of years, from pre-Columbian times to today. The latest of these ceremonies happened in early May.Joining Ira to talk about the importance of astronomical ceremony is Willy Barreno, a Maya calendar keeper based in Quetzaltenango, Guatemala, and Dr. Isabel Hawkins, astronomer and senior scientist at the Exploratorium in San Francisco, California.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.