SSS 2009-07-23（在线收听）

This is Scientific Ameican’s 60-Second Science. I’m Steve Mirsky. Got a minute?

“Would you mind telling me what this is all about, Mister?” No problem, Captain. A study in the Journal of Applied Physiology shows that artificial gravity should prevent a big problem faced by astronauts who stay weightless for extended periods. “Are you a doctor?” Well, no, but I know the weightlessness problem: muscle decay.

Fifteen healthy men spent three weeks lying in bed. Such inactivity produces similar muscle losses as weightlessness. But eight of the volunteers were spun around in a NASA centrifuge 30 times a minute for an hour each day. The forces produced are equivalent to standing up in about two and a half times normal gravity. The spun guys kept making leg muscle proteins normally. But muscle production in the unspun group was cut almost in half.

The study has implications for elderly people here on Earth. “I’m 34 years old.” Actually, if today’s 78-year-old Shatner were hospitalized, he’d quickly lose muscle. But getting Bill to stand up and move just a little each day could help him ward off muscle decay. “What are we doing here?” “Maybe they’re throwing us a retirement party.” “That suits me, I just bought a boat.”

Thanks for the minute, for Scientific Ameican’s 60-Second Science. I’m Steve Mirsky.