挠痒之谜与月球农场：读者问答精选

Scratch that What is an itch, and why are most so easily calmed with a simple touch? Tony Burton, Glasgow, UK Planning ahead Are there any plants and creatures that could be taken to the moon and would survive, reproduce and be a viable food source in, say, 25 years’ time? Robin Maguire Hobart, Tasmania, Australia The answer (in principle) is a firm yes, thanks to the Wardian case. This device, invented in the first half of the 19th century, was an airtight box with glass panels in which assemblages of plants, soil and insects could survive for years without attention, even in otherwise hostile environments. The case’s contents recycled themselves, including moisture. …