NASA
Last Word is Â鶹´«Ã½â€™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 lastword@newscientist.com
Black holes are depicted as having doughnut-shaped discs around them, and space telescope images seem to support this. Do they somehow have this shape when viewed in all directions?
Peter Leach
Mold, Flintshire, UK
Ahry/Alamy
What are the pros and cons of using carbon dioxide in tyres?
Roger Everest
Masterton, New Zealand
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 address.
Â鶹´«Ã½ retains total editorial control over the published content and reserves all rights to reuse question and answer material that has been submitted by readers in any medium or in any format.
