Free Wonders
Some of our favourite wonder cards, free forever.
No sign-up, no catch -- these stay free to read for everyone, even after the rest of the library requires a plan.
Everyday Science
Why does ice float on water?
Because ice takes up more space than water.
History & Time
Why do we have leap years?
Because Earth's trip around the sun doesn't divide evenly into days.
Space
Why is the sun so hot?
Because tiny bits of the sun are fusing together deep inside.
Plants & Food
Why does bread turn mouldy?
Because tiny mould spores are floating in the air, waiting to land.
Human Body
Why does hair turn grey?
Because ageing cells slowly stop making colour.
Everyday Science
Why do heavy boats float?
Because their wide shape pushes aside more water than they weigh.
Everyday Science
Why does toast always seem to land butter-side down?
Because table height gives toast just enough time to flip once.
Everyday Science
Why do we get static shocks?
Because tiny charges build up until they jump.
Human Body
Why do eyes look red in flash photos?
Because the flash bounces off blood vessels inside your eye.
Machines & Inventions
Why does metal rust?
Because iron, water, and air react together over time.
History & Time
Why do clocks go clockwise?
Because early clocks copied the shadow on a sundial.
Big Ideas
Why does a mirror flip left and right, but not up and down?
Because a mirror really flips front to back, not left to right.
Human Body
Why do we get chills from music?
Because a surprising musical moment sparks a rush in your brain.
Human Body
Why do we blush?
Because a rush of feeling widens the blood vessels in your face.
Animals
Why do cats knead with their paws?
Because it's a leftover habit from kittenhood.
Tap any card to open the full page -- same photos, same detail as the rest of the library.