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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, January 26, 2021

      Do Lie Detectors Actually Work?
      Are they catching liars or something else?
      Demystified / Science
      Polygraph Lie Detector Machine
      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
      Is It Still Important to Learn Roman Numerals?
      Find out whether Roman numerals are still valuable to know.
      Companion / Science
      Sign on Brick wall reads "1645" written in Roman numeral.
      9 Ghostly Planets
      Were they ever out there to begin with?
      List / Science
      Background: abstract bubble planets with clouds. astrology, astronomy, atomosphere, big bang, bubbles, fantasy, future, galaxy, universe, stars
      Physical science
      Physical science, the systematic study of the inorganic world, as distinct from the study of the organic world, which is...
      Encyclopedia / Science
      Large Hadron Collider
      Space exploration
      Space exploration, the investigation, by means of crewed and uncrewed spacecraft, of the reaches of the universe beyond Earth’s...
      Encyclopedia / Science
      astronaut outside the International Space Station
      Mathematics, the science of structure, order, and relation that has evolved from elemental practices of counting, measuring,...
      Encyclopedia / Science
      Babylonian mathematical tablet
      Philosophy of science
      Philosophy of science, the study, from a philosophical perspective, of the elements of scientific inquiry. This article discusses...
      Encyclopedia / Science

      Science Quizzes

      Mamba. Black mamba snake in a tree in South Africa. The best known Mamba is the black mamba, D. polylepis (Dendroaspis polylepis). Among deadliest of the world's snakes.
      Reptiles: Fact or Fiction?
      How many species of reptiles exist? Do reptiles practice estivation? Sort out the facts in this quiz about cold-blooded creatures.
      Beaver gnawing on log. mammal / rodentia / Castor canadensis
      Of Mice and Other Rodents: Fact or Fiction?
      Are rabbits rodents? Can mice cause fires? Find the answer to these questions and more in this quiz all about rodents.
      Chicken. Gallus gallus. Poultry. Fowl. Animal. Bird. Rooster. Cocks. Hens. Beak. Wattle. Comb. Farm animal. Livestock. Close-up profile of a hen's head.
      Bird’s Eye View: Fact or Fiction?
      Are chickens related to pheasants? How many varieties of turkeys exist? Sort out the fact and gain a new perspective on these...
      hyena in grassland; mammal, canine, carnivore
      Hyenas and Aardwolves: Fact or Fiction?
      Where can aardwolves be found? Do hyenas live in trees? Sort out the facts in this quiz about hyenas and aardwolves.
      The brown bear (Ursus arctos), grizzly bear in the wilderness, Alaska.
      Bear in Mind: Fact or Fiction?
      Do brown bears live in the southern hemisphere? Do polar bears travel? Sort out the facts in this quiz about bears.
      Dama gazelle (Nanger (or Gazella) dama)
      Antelopes: Fact or Fiction?
      Do antelopes have good hearing? Do gazelles have any teeth? Discover the answers to these questions and more in this quiz...
      Cattle. Cow. Bovine. Livestock. Farm animals. Pregnant brown and white dairy cow.
      Bovine: Fact or Fiction?
      Which country raises the most cattle? Are cape buffalo the same size as elephants? Sort out the facts in this quiz all about...
      Pig. Hog. Suidae. Sus. Swine. Piglets. Farm animals. Livestock. Pig sitting in mud.
      Animal Adventures: Fact or Fiction?
      Can animals survive being frozen? Do only male animals have antlers? Test your knowledge of a variety of incredible animals...
      Three types of eels. Fish / Anguilliformes / American eel (Anguilla rostrata), European eel (Anguilla anguilla), conger eel (Conger oceanicus)
      Eels: Fact or Fiction?
      Do eels live in freshwater and saltwater? How many kinds of eels exist? Find the answers to these electrifying questions...
      Hedgehogs. Insectivores. Erinaceus europaeus. Spines. Quills. Close-up of a hedgehog rolled up.
      Animal Jumble: Fact or Fiction?
      Are elks vegetarians? How much does the smallest mongoose weigh? Test your knowledge of a diverse group of animals from the...
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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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