New Questions from Last Word Series

If aliens with technology similar to ours lived on a planet orbiting Proxima centauri (the next-nearest star), would we be able to see unmistakable signs of a technological civilisation? Of life? And what is the advantage of eggs over live births?

This question was posed as part of New Scientist’s Last Word series, in which readers give scientific answers to each other’s questions. Here’s what our readers had to say