Facts for Ages 11–13
1607 facts perfect for this age group
Contrary to popular belief, most of the Sahara is not sandy — only about 25% is covered in sand dunes, with the rest consisting of rocky plateaux, mountains, and gravel plains.
About 90% of the world's earthquakes occur along the Ring of Fire, a horseshoe-shaped zone around the edges of the Pacific Ocean.
The Earth's liquid iron core generates a magnetic field that extends far into space, protecting us from harmful solar radiation and allowing compasses to work.
The hydrochloric acid in your stomach is strong enough to dissolve zinc, but a thick layer of mucus protects the stomach lining from digesting itself.
Before humans arrived, New Zealand had no native land mammals except for bats. The islands were instead home to many unique bird species, including the kiwi.
Duck-billed dinosaurs called hadrosaurs had elaborate hollow crests on their heads that scientists believe they used to produce low, resonating calls. The crests acted like a trombone, amplifying sounds to communicate across dense forests.
Scientists use sonar technology — which sends out sound pulses and measures the echo — to map the underwater landscape. We have more detailed maps of the surface of Mars than we do of Earth's own ocean floor.
Some neutron stars, called pulsars, can spin over 700 times per second, which is faster than a kitchen blender.
Every time a cell divides, it must copy all 3 billion base pairs of DNA in the human genome with remarkable accuracy — the error rate is about one mistake per billion letters copied.
Lake Titicaca on the border of Peru and Bolivia is the world's highest navigable lake, sitting at an altitude of 3,812 metres above sea level.
Sand tiger shark embryos develop teeth while still in the womb and eat their unborn siblings. By the time they are born, only the two biggest and strongest embryos survive — one from each uterus.
In 1736, Euler solved the famous Seven Bridges of Königsberg puzzle by proving it was impossible to cross all seven bridges exactly once. In doing so, he invented a whole new branch of mathematics called graph theory.
A day on Venus is longer than a year on Venus! Venus rotates so slowly that it takes 243 Earth days to spin once, but only 225 Earth days to orbit the Sun. Venus also spins backwards compared to most planets.
Turmeric has been used as medicine and spice for over 4,000 years. The compound that gives it its bright yellow colour — curcumin — is still studied by scientists for its potential anti-inflammatory properties.
Chaos theory shows that tiny differences in starting conditions can lead to wildly different outcomes. This is sometimes called the butterfly effect — the idea that a butterfly flapping its wings could theoretically influence a distant tornado.
The Collatz conjecture has a simple rule: take any number, if even divide by 2, if odd multiply by 3 and add 1, and repeat. Every number tested always eventually reaches 1, but no mathematician has ever proven this must always be true.
The number 1,729 is called the Hardy-Ramanujan number. When Hardy visited the ill Ramanujan in hospital and mentioned arriving in taxi number 1,729, Ramanujan instantly replied it was interesting — it's the smallest number expressible as the sum of two cubes in two different ways: 1³+12³ and 9³+10³.
Cape Horn at the very tip of South America is where the Atlantic and Pacific Oceans meet. It is one of the most dangerous stretches of water for sailors because of powerful storms and enormous waves.
Antarctica has active volcanoes hiding beneath its ice. Mount Erebus is the world's southernmost active volcano and has had a rare lava lake bubbling in its crater for decades.
The Rhind Mathematical Papyrus, dating to around 1650 BCE, is one of the oldest known math textbooks. Written in ancient Egypt, it contains 87 problems covering fractions, geometry, and simple algebra.