Stopping signs of life and starting them again might seem like pure sci-fi—but cell biologist Mark Roth says it's very possible. In this podcast, he explains why.Podcast produced by David Levin. NOVA is produced by WGBH in Boston. Funding for NOVA is provided by David H. Koch, the Howard Hughes Medical Institute, the Corporation for Public Broadcasting, and public television viewers.Learn about other ways that science is extending human life. Go to pbs.org/nova/sciencenow.