51动漫

cinematic flight through dark deep space asteroid field with stars; Shutterstock ID 2687214359; purchase_order: -; job: -; client: -; other:

If Earth exploded, how many rocks would have signs of life?

The answer to this question very much depends on what destroyed Earth, explains one reader

(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 3

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

Why do jewellery chains become so tightly knotted together? part 2

2B5DJY0 Row of homemade jars of jam for sale on the market counter.

This week鈥檚 new questions

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?

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?

Perhaps surprisingly, the salt concentration of the oceans has been fairly constant over at least the past 500 million years

Why do we use pillows? part 2

This week鈥檚 new questions

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

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