杏吧原创

Why do humans feel the urge to share their thoughts with others?

Sharing knowledge is key to our survival as a species, say our readers.

Do left- and right-handedness exist in animals? part 2

How can gravity escape a black hole? part 2

This week鈥檚 new questions

Two scientists use a massive, illuminated periodic table of elements as they discuss the element holmium in the Lawrence Hall of Science at the University of California, Berkeley. (Photo by ?? Ted Streshinsky/CORBIS/Corbis via Getty Images)

How many elements of the periodic table could we safely get rid of?

Close-up view of Black hole with Earth planet in deep space. Realistic science fiction art. Elements of this image furnished by NASA.; Shutterstock ID 2169109081; purchase_order: -; job: -; client: -; other:

If nothing can escape a black hole, how come gravity seems to?

High five from a cute scruffy dog with a big smile! Cream wall background, shallow depth of field. Clever dog, the Bailey lightbox

Does left- and right-handedness exist in animals?

Close up photo of peony flower bud with water drops at sunlight after rain in garden. Natural floral background. Gardening, spring season, growth concept.; Shutterstock ID 1726658389; purchase_order: -; job: -; client: -; other:

This week鈥檚 new questions

Is there an equivalent of being ambidextrous for feet?

Why do people scrunch up their eyes to see more clearly? Part 2

Why do people scrunch up their eyes when they want to see more clearly? It seems to be counterintuitive. (continued)

This week鈥檚 new questions

Why don鈥檛 coffee bags make very good coffee?

What tipping points can we expect to see if we reverse global warming?

This week鈥檚 new questions