Featured in summer 2019
To hit renewables targets, countries are sharing energy across borders
It takes a lot more than adding wind turbines and solar panels to transform a giant power grid.
Solve the famous water puzzle from Die Hard 3
Tackle this brain teaser with a vengeance.
Can you count all the triangles in these images? (Hint: There are more than you think.)
These polygons contain multitudes.
There’s a reason looking at food photos makes you hungry
They trick your brain into making your tummy rumble.
These strawberries aren’t red. Here’s why your brain is sure they are.
Color constancy is playing tricks on you.
Counting decapitated sperm and other time-consuming science tasks
Are we done yet?
Horseshoe crab blood is rare but crucial for medicine, so this scientist came up with a solution
The rarest blood is blue.
Three alternative ways to charge your phone
Sunlight, fire, and even a hand crank can pump juice into your device in a pinch.
How many people can the planet actually hold?
There's always room for one more.
Inside New York City’s vanishing community of repair shops
Skilled fixers still service everything from cameras to denim.