The Download: longevity myths, and sewer-cleaning robots

"These days at 70 years old you are still a child," China's Xi Jinping, 72, was translated as saying. "With the developments of biotechnology, human organs can be continuously transplanted, and people can live younger and younger, and even achieve immortality," Russia's Vladimir Putin, also 72, is reported to have replied. In reality, rounds of organ transplantation surgery aren't likely to help anyone radically extend their lifespan anytime soon. And it's a simplistic way to think about aging--a process so complicated that researchers can't agree on what causes it, why it occurs, or even how to define it, let alone "treat" it. This article first appeared in The Checkup, MIT Technology Review's weekly biotech newsletter.