Stocktrek Images, Inc./Alamy
What is the minimum number of working individuals that would be necessary for the survival of a settlement on Mars?
Howard Ritter,
Perrysburg, Ohio, US
Ernesto Rogata/Alamy
Why aren’t we equally capable with our left and right sides? Wouldn’t this have given us a survival advantage?
Celine Szoges Schwartz,
Thornbury, Ontario, Canada
To answer this question – or ask a new one – email lastword@newscientist.com.
Questions should be scientific enquiries about everyday phenomena, and both questions and answers should be concise. We reserve the right to edit items for clarity and style. Please include a postal address, daytime telephone number and email…
