Science
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.
Browse Subcategories
Featured content, November 28, 2025
cell
Cell, in biology, the basic membrane-bound unit that contains the fundamental molecules of life and of which all living things...
Copley Medal
Copley Medal, the most prestigious scientific award in the United Kingdom, given annually by the Royal Society of London...
heredity
Heredity, the sum of all biological processes by which particular characteristics are transmitted from parents to their offspring....
meta-analysis
Meta-analysis, in statistics, approach to synthesizing the results of separate but related studies. In general, meta-analysis...
astronomy
Astronomy, science that encompasses the study of all extraterrestrial objects and phenomena. Until the invention of the telescope...
Scientific Revolution
Scientific Revolution, drastic change in scientific thought that took place during the 16th and 17th centuries. A new view...
analysis
Analysis, a branch of mathematics that deals with continuous change and with certain general types of processes that have...
principles of physical science
Principles of physical science, the procedures and concepts employed by those who study the inorganic world. Physical science,...
Science Quizzes
Casting Call
You may be familiar with Sean Connery in this iconic role, but has actor Roger Moore also played the character of "Bond,...
Castles: Fact or Fiction?
Are you a castle connoisseur, or does your knowledge end at Disneyland? Test your castle cred with this quiz.
Cat Quiz
How much do you know about cats?
Caviar Quiz
Do you have expensive taste? Test your knowledge of caviar.
How To Celebrate Christmas Quiz
Okay, so you know howyou celebrate Christmas. But what about everyone else? Take this quiz and find out how Christmas...
Celebrities’ Pets’ Names
Celebrities have some very cute animals to call their own, and they give them some of the cutest names too. Test your knowledge...
Cervantes
Miguel de Cervantes is much more than Spain's most famous novelist. Test what you know about him with this quiz.
Challenging Standardized Test Words Quiz: Vol. 1
Here are 20 terms to help you score 1600. Find the answer that best describes the italicized standardized test word.
Challenging Standardized Test Words Quiz: Vol. 2
No number two pencil is required. Find the answer that best describes the italicized Standardized Test word.
Challenging Standardized Test Words Quiz Vol. 3
You’re on your own for the math section.
Science Videos
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Science Subcategories
AstronomyHuman beings have long been fascinated by the celestial sphere above, whose twinkling lights have inspired not only scientific theories but also many artistic endeavors. Humankind's fascination with the world beyond Earth has led to many landmark moments in history, as when space exploration took a giant step forward with the advent of technology that allowed humans to successfully travel to the Moon and to build spacecraft capable of exploring the rest of the solar system and beyond.
Articles
- Neil ArmstrongAmerican astronaut
- starastronomy
- Valentina TereshkovaSoviet cosmonaut
BiologyHow do plants feed themselves? How did dogs evolve from wolves? What good is the appendix in humans, anyway? Such questions fall within the domain of biology, which seeks to understand living organisms and their vital processes (although the jury’s still out on what our appendixes are for). Biology’s diverse fields include botany, ecology, evolution, genetics, medicine, physiology, and zoology.
Articles
Birds, Reptiles & Other VertebratesAlthough 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).
Articles
- amphibiananimal
- chondrichthyanfish class
- fishanimal
Insects & Other Invertebrates 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 the 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.
Articles
- nematodeanimal
- giant squidmollusk
- butterflyinsect
ChemistryHow 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 the miniscule and unassuming atom.
Articles
- rare-earth element
- periodic tablechemistry
- neonchemical element
Earth Science, Geologic Time & FossilsPlanet 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 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.
Articles
- Conrad Schlumberger and Marcel SchlumbergerGerman geophysicists
- Hadean Eongeochronology
- Keeling Curveatmospheric science
EnvironmentBiological 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.
Articles
- hydrosphereEarth science
- environmentbiology
- recycling
MammalsMammals are distinguished by their ability to produce milk. The class Mammalia boasts tremendous diversity in form and habit, and different types of mammals can be wildly different from one another in physical appearance. Living kinds of mammals range in size from a bat weighing less than a gram to the largest animal that has ever lived, the blue whale, which reaches a length or more than 30 metres (100 feet) and a weight of 180 metric tons (nearly 200 short [U.S.] tons).
Articles
MathematicsMathematics is a science of structure, order, and relation that deals with logical reasoning and quantitative calculation. The history of mathematics can be traced back to ancient Mesopotamia; ancient clay tablets have proven 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.
Articles
- numbermathematics
- foundations of mathematics
- Millennium Problemmathematics
PlantsLife 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). 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.
Articles
- Rafflesiaceaeplant family
- roseplant
- cereuscactus genus
PhysicsWhat’s the matter? Matter is the material substance that constitutes our whole observable universe, and it is the subject of study of physics. Physics, the basic physical science, studies objects ranging from the very small (using quantum mechanics) to the entire universe (using general relativity). It deals with the structure of matter and how the fundamental constituents of the universe interact.
Articles
- seismograph
- geomagnetic fieldgeophysics
- mechanicsphysics

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