女生小视频

In the Medical Laboratory, Anonymous Female Patient Lying on a CT or MRI Scan Bed Undergoes Scanning Procedure with Red Lasers. Advanced Healthcare Facility with High-Tech Equipment; Shutterstock ID 2587414477; purchase_order: -; job: -; client: -; other:

Why are MRI machines so noisy and what stops us making them quieter?

The noise of an MRI machine is just an unfortunate by-product of their construction, explain our readers

Will the ocean ever be too salty for life to thrive? Part 2

Planet in water - Moon. Science fiction art. Solar system. Elements of this image furnished by NASA; Shutterstock ID 579784837; purchase_order: -; job: -; client: -; other:

If all Earth鈥檚 water were put in a ball, how large would it be? Part 2

2HR09CM Killer whale, Orcinus orca, spy hop, Vestfjord, Ofotfjord, and Tysfjord, Lofoten Islands, Norway, Atlantic Ocean

This week鈥檚 new questions

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

Do birds actually sleep more in winter?

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?

A jewellery chain, like everything else in the universe, is subject to the second law of thermodynamics, explains one reader

Why do we scream in fear? part 2

This week鈥檚 new questions

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

Why do we scream in fear?