This week’s new questions

What is the advantage of eggs over live births? Brian Shipman Maidenhead, Berkshire, UK If aliens with technology similar to ours lived on a planet orbiting Proxima Centauri (our next-nearest star), would we be able to see unmistakable signs of a technological civilisation? Of life? Chris Greenlaw Vancouver, Canada Advertisement Last Word is New Scientist’s long-running series in which readers give scientific answers to each other’s questions, ranging from the minutiae of everyday life to absurd astronomical hypotheticals. To answer a question or ask a new one, email [email protected] To answer this question – or ask a new one – email [email protected]. 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 address. The use of AI tools (e.g. ChatGPT, Claude) to write either questions or answers is forbidden, and any submissions found to have been written using AI tools will be withdrawn.