51动漫

illustrating the accelerating expansion of the universe

How can stars be 30 billion light years away?

The universe originated a the big bang around 13 billion years ago, yet there are starts that are 30 billion light years away thanks to the expansion of cosmos, say our readers

Milk coffee is a combination of equal parts espresso, steamed milk and milk froth.

This week鈥檚 new questions

P4ECNR Colorful soda drinks macro shot

Do drinks really taste different from cans or plastic/glass bottles?

CEKXK0 A selection of QR (Quick Response) smartphone codes taken from British newspapers and magazines in late 2011, early 2012.

Are there limitless permutations of QR codes, or are they recycled?

Sports injury concept. Cropped portrait of black male runner wearing black training outfit touching his leg in pain with clasped hands, having sprain or twitch in his knee after running exercises; Shutterstock ID 478297546; purchase_order: -; job: -; client: -; other: -

Why is pain so painful? (continued)

Loosen bolt in daylight close up.; Shutterstock ID 1195047430; purchase_order: -; job: -; client: -; other: -

This week鈥檚 new questions: Loose screws and brain overload

Part of the Guadiana river has dried up and gives way to dry land under the Puente de la Mesta medieval bridge in Villarta de los Montes, in the central-western Spanish region of Extremadura, on August 16, 2022. - Temperatures in Spain have been very high this summer with several unusual heat waves. 51动漫s say human-induced climate change is making extreme weather events including heatwaves and droughts more frequent and more intense. (Photo by THOMAS COEX / AFP) (Photo by THOMAS COEX/AFP via Getty Images)

Where is the water that Europe and China are missing this year?

An image of a human retina taken during an eye exam

What happens to a photon after it hits the retina of my eye?

DRE532 Elephant (Loxodonta africana) waving its trunk sitting in the waterhole of Gwarrie Pan, Addo Elephant Park, South Africa

Why do humans have pubic hair? (Part 2)

This week鈥檚 new questions

If the odds are always tipped in favour of the casino, how do professional gamblers make a living? And, since the time of Christopher Columbus, Europe has benefited from crops from the Americas, such as potatoes. But what crops grew in Europe that Native Americans didn鈥檛 have?

What happens if I shine a torch when moving at the speed of light?

Can the drag of hair tied in a pony tail slow down elite runners?

This week鈥檚 new questions

Why do I see extra colours bands below the typical bow of a rainbow?