All facts — Page 41
The complete ONAURE library, newest first. Every fact has an explanation and a source you can check.
2056 facts
The astronomer Tycho Brahe wore a metal prosthetic nose.
Tycho Brahe lost part of his nose in a duel in 1566 and had a prosthetic nose made of silver and gold. He was one of…
The smell of wet earth after rain is called petrichor.
Petrichor is caused by a mixture of compounds, including geosmin, produced by soil bacteria, and ozone brought by the…
A rainbow is actually a full circle.
From the ground, we only see the upper half of a rainbow. From above, for example from an aeroplane or a mountain, it…
Cactus spines are modified stems.
Cactus spines are modified leaves. Over the course of evolution, the leaves became spines to reduce water loss and…
Fireflies produce light without heat, with over 90 percent efficiency.
Fireflies produce light through a chemical reaction called bioluminescence, in which the enzyme luciferase acts on…
The air we breathe is composed of about 78 percent nitrogen.
Atmospheric air is composed of about 78 percent nitrogen, 21 percent oxygen and 1 percent other gases, such as argon…
Sunlight takes about 8 minutes to reach Earth.
Sunlight travels at 300,000 kilometres per second and covers the average distance of 150 million kilometres between…
Mars has two moons the size of Earth s Moon.
Mars has two very small moons, Phobos and Deimos, with diameters of only 22 and 12 kilometres, respectively. They are…
Io, Jupiter's moon, is the most volcanically active body in the solar system.
Io has more than 400 active volcanoes, making it the most volcanically active body in the solar system. The intense…
The term Wi-Fi does not mean anything.
Wi-Fi was a name invented by a marketing company for a wireless communication standard. In fact, it does not mean…
The first computer virus appeared in 1971 and was called Creeper.
The first known computer virus was called Creeper and was created in 1971 by Bob Thomas on ARPANET. It was not…
Ethernet was invented in the Xerox PARC laboratories.
Ethernet was invented in 1973 by Bob Metcalfe at the Xerox PARC laboratories in California. It was created to connect…
A tiger's roar can be heard up to 3 kilometres away.
The roar of an adult tiger can be heard about 3 kilometres away, thanks to the special structure of its larynx and…
The sex of sea turtles is determined by chromosomes.
The sex of sea turtles is determined by the temperature of the sand where the eggs are incubated. Higher temperatures…
Each dragonfly eye has more than 30,000 facets.
Dragonfly compound eyes contain up to 30,000 tiny lenses called ommatidia, giving them a nearly complete panoramic…
Human venous blood is not blue, but dark red.
Venous blood is often depicted as blue in books, but it is actually dark red. The bluish colour we see in veins is…
Hiccups are caused by the involuntary contraction of the liver.
Hiccups are caused by the involuntary contraction of the diaphragm, the muscle that separates the chest from the…
Bananas release a gas that makes other fruits ripen faster.
Bananas produce ethylene, a gas that accelerates the ripening of nearby fruits. That is why placing a banana next to…
Dark roast coffee has more caffeine than light roast.
Light roast coffee beans generally have more caffeine than dark roast, because longer roasting destroys part of the…
The smell of garlic only appears when the clove is cut or crushed.
Whole garlic contains alliin, an odourless compound. When the clove is cut or crushed, the enzyme alliinase converts…
The most isolated point in the ocean is called Point Nemo.
Point Nemo, in the South Pacific, is the point in the ocean farthest from any land. The nearest human is often aboard…
Blood Falls in Antarctica are caused by red algae.
Blood Falls in Antarctica owe their red colour to iron oxide, not algae. The salty, iron-rich water flows from a…
The Altamira cave in Spain has cave paintings over 14,000 years old.
The Altamira paintings, discovered in 1879, include bison, horses and human handprints painted on the walls. They are…
A bee can carry up to half its own body weight in nectar.
Worker bees carry nectar and pollen in their stomachs and on their hind legs. Consequently, they can carry up to half…