51动漫

B1GCT0 Satellite Image of The Earth from Space

What would Earth be like if life had never existed?

Without life, our planet would be a hostile and alien place 鈥� and possibly even a nondescript brown colour

a metal water barrel stands in the garden; Shutterstock ID 1980910310; purchase_order: -; job: -; client: -; other: -

How does water become stale?

If sitting cross-legged is unhealthy, why is it so comfortable? Part 2

Common frog (Rana temporaria) sheltering from rain under toadstool (Macrolepiota procera) the Netherlands

This week鈥檚 new questions

an explosion of colored particles on a dark background, composition on the theme of science, molecular physics, space and a festive background

How does a photon know to travel at the speed of light?

KMXN2B Beautiful fun happy smiling African American couple wearing white shirts laying in grass, faces of woman and man next to eachother in opposite

Why do humans show their teeth to signal friendship or mirth?

2D6CTBM Wedding candy bar with different colored bright cupcakes, macaroons, cakes, jelly and fruits.

This week鈥檚 new questions

Is the sky really clearer early in the morning? If so, why?

Unrecognizable African American guy crossing fingers while supporting football team with blurred friend while watching match in field (Unrecognizable African American guy crossing fingers while supporting football team with blurred friend while watchi

What is the evolutionary reason for superstitious behaviour?

Time concept. Men back in front of a clock.

This week鈥檚 new questions

Aside from our perception, how can we know that time exists? And are there any evolutionary benefits to perimenopausal hot flushes?

What is the smallest whole number with no interesting properties?

If the speed of light changed, how would it affect our lives?

This week鈥檚 new questions

Why are bird droppings mostly white, considering the things birds eat?