All facts — Page 8
The complete ONAURE library, newest first. Every fact has an explanation and a source you can check.
1196 facts
The characteristic smell of rain is called petrichor and is caused by soil bacteria.
Petrichor is produced when geosmin, a compound released by soil bacteria called actinobacteria, is released into the…
Giant sequoias depend on fire to reproduce.
The cones of giant sequoias need the intense heat of forest fires to open and release seeds. Fire also clears the…
Koalas have fingerprints so similar to human ones that they are hard to tell apart under a magnifying glass.
Although koalas are marsupials and humans are primates, both evolved to grip tree trunks and branches. That…
Cows form close friendships and become stressed when separated from their best friends.
Animal behaviour studies have shown that cows create strong social bonds with specific companions. When separated…
Dolphins sleep with only half of their brain at a time, keeping the other half alert.
As marine mammals, dolphins need to surface to breathe. If they fell completely asleep, they would drown. Therefore…
Humans are the only primates that cannot produce their own vitamin C.
Most mammals synthesise vitamin C in the liver from glucose. Humans, along with fruit bats and guinea pigs, lost this…
The original carrots were purple or white, not orange.
The carrot cultivated thousands of years ago in Central Asia was originally purple or white. The orange variety we…
The Aztecs used cocoa beans as currency, and there were counterfeiters who made beans out of clay.
In the Aztec Empire, cocoa was so valuable that it served as money. A rabbit cost about ten beans, and a slave could…
The deepest point in the ocean is deeper than Mount Everest is tall.
The Challenger Deep, in the Mariana Trench, reaches about 11,000 metres deep. Mount Everest is 8,849 metres high. If…
The Caspian Sea is the largest lake in the world and is bigger than many countries.
With about 371,000 square kilometres, the Caspian Sea is larger than Germany or Japan. Despite its name, it is a…
The Sahara Desert is almost the size of the United States.
The Sahara covers about 9.2 million square kilometres, while the United States has approximately 9.8 million. Despite…
Cleopatra lived closer in time to the invention of the iPhone than to the construction of the Great Pyramid of Giza.
The Great Pyramid was built around 2560 BC. Cleopatra lived between 69 and 30 BC, about 2,500 years later. The first…
Lightning strikes the Earth about 100 times per second.
It is estimated that between 50 and 100 electrical discharges occur per second worldwide, adding up to about 8…
Giant sequoias have bark so resistant to fire that they survive forest fires.
Sequoia bark can be up to 60 centimetres thick and is poor in resin, which makes it hard to burn. In addition, the…
Mount Everest grows a few millimetres per year due to the movement of tectonic plates.
The collision between the Indian plate and the Eurasian plate continues to push the Himalayas upwards. Satellite…
The Moon is moving away from the Earth by about 4 centimetres per year.
The Moons gravity causes tides in the Earths oceans. This movement creates friction that transfers energy from the…
The first mobile phone weighed almost a kilogram and cost the equivalent of several thousand euros.
The Motorola DynaTAC 8000X, launched in 1983, weighed about 790 grams and measured 25 centimetres without the…
The wood frog can survive frozen for weeks.
During winter, up to 65 percent of the wood frogs body freezes. Its heart stops beating, breathing ceases and blood…
Sharks have no bones, their skeleton is made of cartilage.
Unlike most fish, sharks and rays have a skeleton entirely made of cartilage. Cartilage is lighter and more flexible…
Dung beetles use the Milky Way to navigate at night.
When rolling a ball of dung, dung beetles need to travel in a straight line so they do not return to the starting…
The human nose can distinguish more than one trillion different odours.
For decades it was thought that the human nose could only distinguish about 10,000 odours. A 2014 study published in…
The cornea of the human eye has no blood vessels, which is why it is transparent.
The cornea is the transparent layer at the front of the eye. To maintain transparency, it cannot have blood vessels…
The human body contains enough iron to make a small nail.
Most of the bodys iron is in haemoglobin, the protein in red blood cells that carries oxygen. In total, an adult has…
Chillies do not contain heat, they only activate the pain receptors on the tongue.
Capsaicin, the molecule that makes chillies hot, binds to TRPV1 receptors, the same ones that detect heat. The brain…
