Uruguay
Uruguay is a small country in southeastern South America, lying on the Atlantic coast between its two giant neighbours, Brazil and Argentina. The…
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The Atom
The atom is the basic building block of ordinary matter, the smallest unit of a chemical element that retains its properties. Everything you can see…
Kangaroo
The kangaroo is a large marsupial native to Australia and the unofficial emblem of that country. Famous for hopping on its powerful hind legs and for…
Mount Everest
Mount Everest is the highest mountain on Earth as measured from sea level, with a summit reaching 8,848.86 metres (29,031.7 feet) above sea level, a…
General Relativity
General relativity is Albert Einstein's theory of gravity, published in 1915. It reimagines gravity not as a force pulling objects together but as…
The Speed of Light
The speed of light in a vacuum is a fixed, fundamental constant of nature, equal to about 299,792 kilometres per second. It is the fastest speed at…
Mount Kilimanjaro
Mount Kilimanjaro in Tanzania is the highest mountain in Africa and the tallest free-standing mountain in the world, rising about 5,895 metres above…
Victoria Falls
Victoria Falls is one of the largest and most spectacular waterfalls on Earth, on the Zambezi River at the border between Zambia and Zimbabwe in…
The Pythagorean Theorem
The Pythagorean theorem is one of the most famous results in all of mathematics. It states that in a right angled triangle, the square of the longest…
Penguin
Penguins are flightless seabirds superbly adapted to life in the water, where they fly in all but name, using their stiff, flipper-like wings to…
Nikola Tesla
Nikola Tesla was an inventor and electrical engineer best known for his pioneering contributions to the alternating current electrical system that…
The Fermi Paradox
The Fermi paradox is the puzzling contrast between the high apparent likelihood that alien civilizations exist somewhere in our vast galaxy and the…
Taj Mahal
The Taj Mahal is a white marble mausoleum in Agra, India, widely regarded as one of the most beautiful buildings in the world. Built in the…
Antarctica
Antarctica is Earth's southernmost continent, a vast, frozen wilderness centred on the South Pole. It is the coldest, driest, windiest, and, on…
Albert Einstein
Albert Einstein was a German born theoretical physicist widely regarded as one of the greatest scientists of all time. Born in 1879 in Ulm, he…
Marie Curie
Marie Curie was a Polish born physicist and chemist who conducted pioneering research on radioactivity, a term she coined. Born Maria Skłodowska in…
Gravity
Gravity is the universal attractive interaction between masses, described at low energy by Newton's law of universal gravitation and at all energies…
Goldbach's Conjecture
Goldbach's conjecture is one of the oldest and simplest sounding unsolved problems in mathematics. It states that every even whole number greater…
Bloodletting
Bloodletting was the practice of deliberately draining blood from a patient to cure or prevent illness. For more than two thousand years it was one…
The Solar System
The Solar System is the Sun and everything bound to it by gravity: eight planets, several dwarf planets, scores of moons, and countless smaller…
Are Viruses Alive?
Whether viruses count as living organisms is a question biologists have debated for over a century, and there is still no settled answer. Viruses sit…