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How can the sky be blue one day and stormy the next? Why do heavy objects tend to fall downwards when dropped? How are birds able to fly (and why can’t I do the same?)? Human beings have long been curious about the world in which we live, striving to identify connections among the phenomenons we witness and to understand how it all works. The field of science has developed over many centuries as a way of studying and understanding the world, beginning with the primitive stage of simply noting important regularities in nature and continuing through the rise of modern science. The modern-day sciences cover a vast range of fields, including biology, chemistry, meteorology, astronomy, physics, and much more.
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Featured content, February 01, 2021

How Mike the Chicken Survived Without a Head
A farmer beheaded a chicken and was surprised when it got up and started running around again.
#WTFact / Science
Domestic chickens (Gallus) on a farm. Rooster hen poultry bird fowl
Deviously Darwinian: 6 Strange Evolutionary Phenomena
Life will find a way. Usually a gross one.
List / Science
Newt. Salamanders. Amphibian. Alpine newts. Ichthyosaura alpestris. Caudata. Urodela. Alpine newt swimming underwater.
The Anthropocene Epoch: Adding Humans to the Chart of Geologic Time
On August 29, 2016, the Anthropocene Working Group recommended that the Anthropocene Epoch be made an official geologic unit.
Companion / Science
Thermonuclear hydrogen bomb, code-named MIKE, detonated in the Marshall Islands in the fall of 1952. Photo taken at a height of 12,000 feet, 50 miles from the detonation site. (Photo 6 of a series of 8) Atomic bomb explosion nuclear energy hydrogen energy
Is Zero an Even or an Odd Number?
Or is this oddly fascinating number even a number at all?
Demystified / Science
number zero, 0 balloon
Chemical bonding
Chemical bonding, any of the interactions that account for the association of atoms into molecules, ions, crystals, and other...
Encyclopedia / Science
crystal bonding
Anthropocene Epoch
Anthropocene Epoch, unofficial interval of geologic time, making up the third worldwide division of the Quaternary Period...
Encyclopedia / Science
Anthropocene Epoch
STEM, field and curriculum centred on education in the disciplines of science, technology, engineering, and mathematics (STEM)....
Encyclopedia / Science
Mass extinction event
extinction: Mass extinctions:
Encyclopedia / Science

Science Quizzes

trees deciduous and coniferous. trees grow on a bank of a forest in springtime in Alberta, British Columbia, Canada. logging, forestry, wood, lumber, wilderness
All Things Green Quiz
No need to romaine calm—it’s the plant quiz you’ve been waiting for! No matter how busy your week has been, there...
Archaea at Midway Geyser Basin in the Grand Prismatic Spring, Yellowstone National Park, Wyoming. Largest hot spring in Yellowstone, third largest in the world. Temp. 147-188F Dim. 250x380 ft. Archaeon, archeon, Yellowstone Geysers, algae
How the Earth Works: A Quiz
The Earth sciences tell us how the Earth works. See how much of an Earth scientist you are by taking this quiz.
Giraffe standing in grass, Kenya.
Know Your Mammals Quiz
Where can you find a capybara? How many cervical vertebrae do giraffes have? Test your knowledge of mammals by taking this...
Cross section of Earth showing the core, mantle, and crust
The Solid Earth Quiz
The term geology refers, according to Britannica, the...
Encyclopaedia Britannica thistle graphic to be used with a Mendel/Consumer quiz in place of a photograph.
36 Questions from Britannica’s Most Popular Science Quizzes
How well do you know astronomy? How about quantum mechanics? This quiz will take you through 36 of the hardest questions...
Three flint axes from the stone age. (prehistoric, tools, early humans, culture, archaeology, implements)
Quick Quiz: Humans and Their Remains
Lucy and ?tzi and the Java Man, oh my! Dive into the world of prehistoric humans in this quick quiz to see just how much...
The Space Shuttle Columbia soars from Launch Pad 39A on July 1 1997 to begin the 16-day STS-94 Microgravity Science Laboratory-1 (MSL-1) mission.
People in Space Quiz
People have been traveling into space, in a physical sense, since the 20th century. But people have been looking into space,...
Laboratory glassware (beakers)
Know Your Chemistry Quiz
From the elements of the periodic table to the processes that create everyday objects—these are just a few of the things...
M101 (NGC 5457, The Pinwheel Galaxy). Hubble Space Telescope image of face-on spiral galaxy Messier 101 (M101). Largest most detailed photo of a spiral galaxy that has ever been released from Hubble. Created from 1994-2003
Everything in Space in a 25-Minute Quiz
Ever wanted to visit everything in outer space in only 25 minutes? Now you can with this quiz, which will rocket you from...
Buffalo Bill. William Frederick Cody. Circus poster, I am coming, Col. W.F. Cody. Portrait of Buffalo Bill (1846-1917) on stampeding bison (buffalo). Folk hero of the American West. Chromolithograph, c1900
Buffalo or Bison?
What’s the difference between buffalo and bison? Take this quick quiz to find out.
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Science Subcategories

Neil Armstrong Astronomy
Human beings have always been fascinated by the celestial sphere above, whose twinkling lights have inspired many theories and artistic endeavors. Study of the solar system has provoked more than just peaceful meditation, however; a major controversy among astronomers arose in the 16th century when Copernicus publicly championed heliocentrism, a Sun-centric model of the solar system that was in direct opposition to Ptolemy's Earth-centered model, which had been generally accepted from the 2nd century CE onward. But humankind's fascination with the world beyond Earth has also led to some landmark moments in history, as when space exploration took a giant step forward with the advent of technology that allowed humans to travel to the Moon and to build spacecraft capable of exploring the rest of the solar system and beyond.
subcategory placeholder Biology
If it’s alive, biology will define it, study it, observe all its functions, follow its vital processes, and interact with it, all in order to understand the life that animates it. In one of biology's best-known examples of such studious investigation, Charles Darwin came up with his scientific theory of evolution by natural selection after systematically observing a variety of plants and animals; his work acted as the foundation upon which modern evolutionary theory is built. But biology’s principles also operate within a plethora of other related fields, including biochemistry, biomedicine, biophysics, and microbiology.
banded fire salamander (Salamandra terrestris) Birds, Reptiles & Other Vertebrates
Although it can be hard to imagine that a peacock and a crocodile have much of anything in common, these animals are actually descendants of the same prehistoric vertebrates. Birds are thought to have descended from carnivorous dinosaurs that began growing feathers by the Late Jurassic Period; thus, birds are technically one lineage of reptiles. This evolutionary link highlights the way in which seemingly incongruous creatures can, in fact, share a common ancestor (though that doesn't mean that we should expect waterfowl and crocodiles to become friends anytime soon).
microfauna Bugs, Mollusks & Other Invertebrates
Some insects are so displeasing to humans that the word "bug" has come to be used as a verb meaning "to bother or annoy." Yet, in addition to being critically important—because they naturally recycle decaying matter—in maintaining balance within the food chain, bugs can also be fascinating creatures, whether in regard to the water strider's ability to run across the surface of water or in regard to assassin bugs' varied and creative means of catching and killing their prey. Mollusks, another group of invertebrates, get less of a bad rap. Their ranks include nearly 100,000 described species of soft-bodied animals that are usually wholly or partly enclosed in a calcium carbonate shell; examples include snails, clams, oysters, squids, and octopuses.
Crustal abundances of elements of atomic numbers 1 to 93. Chemistry
How do you use raw plant materials to manufacture a best-selling perfume? How do you engineer household products that are compliant with environmentally-oriented guidelines? The answers to these questions require an understanding of the laws of chemistry, the science that deals with the properties, composition, and structure of elements and compounds, as well as the transformations that such substances undergo and the energy that is released or absorbed during those processes. Chemistry is also concerned with the utilization of natural substances and the creation of artificial ones. Over time, more than 8,000,000 different chemical substances, both natural and artificial, have been characterized and produced. Chemistry's vast scope comprises organic, inorganic, physical, analytical, and industrial chemistry, along with biochemistry, environmental chemistry, medicinal chemistry, and much more. Through the dedicated efforts of people such as Robert Boyle, Dmitri Mendeleev, John Dalton, Marie Curie, and Rosalind Franklin, the field of chemistry has led to exciting innovations as well as crucial advances in our understanding of how the world functions, starting with just the miniscule and unassuming atom.
Seed fern Earth Science, Geologic Time & Fossils
Planet Earth has billions of years of history, from the time when it was an inhospitable ball of hot magma to when its surface stabilized into a variety of beautiful and diverse zones capable of supporting many life-forms. Many are the species that lived through the various geologic eras and left a trace of their existence in the fossils that we study today. But Earth is never done settling, as we can see from the earthquakes, tsunamis, volcanic eruptions, and other phenomena manifested in Earth’s crust, oceans, and atmosphere.
Earth's 25 terrestrial hot spots of biodiversity Environment
Biological diversity is key to a healthy ecosystem, whether it’s a small biological community or the global biosphere. Ecology, which studies the relationships between organisms and their environment, is an invaluable science that helps us understand what allows an ecological community to thrive.
platypus Mammals
These are the animals to which humans tend to relate the most, perhaps because aspects of their behavior can sometimes resemble the way that we ourselves behave. The protective instinct of a mother bear, the gamboling way that kittens play, and the loyalty displayed by a dog are all traits that we can identify with in the course of our own lives. Mammals are well-equipped to handle different climates and biomes because of their ability to regulate their own body temperatures and internal environment, both in excessive heat and aridity and in severe cold.
subcategory placeholder Mathematics
Although stock portrayals of mathematicians often involve a studious person standing in front of a chalkboard that's covered with mind-bogglingly complex scrawled mathematical problems (call it the "Good Will Hunting" effect), the chaotic-looking equations may obscure the fact that mathematics is, at its heart, a science of structure, order, and relation that deals with logical reasoning and quantitative calculation. There's a method to all that madness! The history of mathematics can be traced back to ancient Mesopotamia, whose clay tablets revealed that the level of mathematical competence was already high as early as roughly the 18th century BCE. Over the centuries, mathematics has evolved from elemental practices of counting, measuring, and describing the shapes of objects into a crucial adjunct to the physical sciences and technology.
Rafflesia flower Plants
Life on Earth owes much to plants. The vast majority of plants carry out photosynthesis to transform light energy into chemical energy, which is the way that virtually all energy in the biosphere becomes available to living things (including us humans). As photosynthetic organisms, plants occupy the base of Earth's food webs and are consumed directly or indirectly by all higher life-forms, thereby functioning as the major source of food for humans and other animals. Plants' photosynthetic activity also produces the air that we breathe: almost all the oxygen in the atmosphere is due to the process of photosynthesis. Still not convinced about the merits of plants? Consider the fact that many plants not only serve up crucial nutrients and breathable air but also look good doing it. Many plants are admired for their striking aesthetic qualities, and flowers such as tulips, lilies, sunflowers, and daisies beautify fields, gardens, windowsills, and bouquets the world over. Plants are also a primary source of consumer goods, such as building materials, textile fibers, and pharmaceuticals.
Schematic diagram of a flotation separation cell. Physics
What’s the matter? The matter is our whole observable universe—with that material substance that constitutes it—and it is the subject of study of physics. The laws that govern motion observed by Newton, the gravitational force that regulates the progress of all celestial bodies, the interaction between subatomic particles, and the nuclear engineering that created the atomic bomb are examples of what this important discipline is all about. Minkowski’s space-time concept, which reformulated Einstein’s special theory of relativity, has bridged physics with philosophy in a conversation that has fascinated the modern concept of physics.
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