Subscribe now

Last word

New Scientist's popular Last Word series gives readers the opportunity to answer each other's questions about everyday science phenomena, from the shape of scones to the evolutionary history of toenails. To answer a question or ask a new one, email lastword@newscientist.com

Part of the Guadiana river has dried up and gives way to dry land under the Puente de la Mesta medieval bridge in Villarta de los Montes, in the central-western Spanish region of Extremadura, on August 16, 2022. - Temperatures in Spain have been very high this summer with several unusual heat waves. Scientists say human-induced climate change is making extreme weather events including heatwaves and droughts more frequent and more intense. (Photo by THOMAS COEX / AFP) (Photo by THOMAS COEX/AFP via Getty Images)

Last Word

Where is the water that Europe and China are missing this year?

Regulars

Trip to the moon (lunar) concept - Long exposure night time rocket launch with solar eclipse

Last Word

What happens if I shine a torch when moving at the speed of light?

Regulars

This week’s new questions

Last Word

This week’s new questions

Regulars

Mandatory Credit: Photo by Ryan Browne/Shutterstock (13048564cx) Eilish McColgan of Scotland celebrates victory in the Women's 10,000m final Commonwealth Games 2022, Day Seven, Birmingham, UK - 3 Aug 2022

Last Word

Can the drag of hair tied in a pony tail slow down elite runners?

Regulars

Portrait of white cat with crown on head sitting on bed, Namibia.

Last Word

This week’s new questions

Regulars

Impressed young asian woman talking on phone with girlfriend while putting mascara in front of mirror at home, sharing rumors; Shutterstock ID 1793035801; purchase_order: -; job: -; client: -; other: -

Last Word

Why do we open our mouths when we put on mascara?

Regulars

2GPFM5E Child in green jacket looking at rainbow over an ocean

Last Word

Why do I see extra colours bands below the typical bow of a rainbow?

Regulars

illustrating the accelerating expansion of the universe

Last Word

This week’s new questions

Regulars

Male legs and hands Weed Out plant gardening in home garden; Shutterstock ID 2087550862; purchase_order: -; job: -; client: -; other: -

Last Word

What stops us from processing weeds into tasty and edible food? Part 2

Regulars

Young african man sitting at airport lounge and sleeping, waiting for flight at airport departure area.

Last Word

Is jet lag worse if you travel east rather than west?

Regulars

FTTG61 Ball of white heavy thread isolated on white

Last Word

Could a word on ball of string be deciphered if the ball unravelled?

Regulars

mist, rain

Last Word

This week’s new questions

Regulars

Piano Exit Overlay Banner Mobile Piano Exit Overlay Banner Desktop