杏吧原创

ENTETC Robin, (Erithacus rubecula), garden bird standing on top of a branch in winter, UK

Do birds actually sleep more in winter?

When birds sit quietly on a branch for long periods during winter, they are not usually sleeping but conserving energy, explain our readers.

Is the concentration of salt in the oceans gradually increasing?

2K18TC6 London, UK. 16th Sep, 2022. Shaikha Al Mazrou, Red Stack, 2022, Lawrie Shabibi - Frieze Sculpture, one of the largest outdoor exhibitions in London, including work by international artists in Regent's Park. Credit: Guy Bell/Alamy Live News

Why do we use pillows? part 2

Close-up of a Cymbiola nobilis shell, also known as the noble volute, against a black background, featuring its distinctive zigzag patterns and smooth texture; Shutterstock ID 2637416271; purchase_order: -; job: -; client: -; other:

This week鈥檚 new questions

2K18TC6 London, UK. 16th Sep, 2022. Shaikha Al Mazrou, Red Stack, 2022, Lawrie Shabibi - Frieze Sculpture, one of the largest outdoor exhibitions in London, including work by international artists in Regent's Park. Credit: Guy Bell/Alamy Live News

What is it about human physiology that leads us to use pillows?

Gold jewelry with space for writing; Shutterstock ID 735656746; purchase_order: -; job: -; client: -; other:

Why do jewellery chains in a box become so tightly knotted together?

(Original Caption) 7/5/1946-The roller coaster is a rough ride, but do they love it! This unposed photo was taken by the intrepid photographer from a front seat, as the car made a stomach-dropping descent. A companion clutched the camera while he clicked the shutter. ACME ROTO SERVICE FOR IMMEDIATE RELEASE BPA 2 #124

Why do we scream in fear? part 2

INDIA. Bangalore. 2016. Laughing Yoga workshop participant Rie Sakamoto

This week鈥檚 new questions

PGRFBG beautiful exoplanet, part of an alien binary star system with a red and blue star (3d space illustration)

Can a planet orbit a binary star system in a figure of eight?

(Original Caption) 7/5/1946-The roller coaster is a rough ride, but do they love it! This unposed photo was taken by the intrepid photographer from a front seat, as the car made a stomach-dropping descent. A companion clutched the camera while he clicked the shutter. ACME ROTO SERVICE FOR IMMEDIATE RELEASE BPA 2 #124

Why do we scream in fear?

While screams can make an individual more conspicuous to predators, they can help other members of their group survive

What good is greed? part 2

This week鈥檚 new questions

Do black holes look doughnut-shaped when viewed in all directions?

What is the evolutionary basis for greed?