Encyclopedia Categories
Today in context,
July 9, 2021
The Hamilton-Burr Duel
In one of history’s most famous duels, Vice Pres. Aaron Burr and Alexander Hamilton faced off on July 11, 1804, following years of acrimony. There were no true victors. Hamilton was fatally shot, and Burr was vilified.
From Founding Father to pop culture icon
Learn more about the life of Alexander Hamilton.
What happened to Burr?
Treason charges, a scheme to conquer Florida, and divorce were just a few things in Burr's eventful life after the duel.
Fact checking Hamilton
Does Lin-Manuel Miranda’s blockbuster Broadway musical get the duel right?
A topless duel?
Read more about the first "emancipated duel" and other notable conflicts that were settled with guns—or swords.
National Kitten Day!
On July 10 we celebrate these cuddly creatures that have been sharing space with humans for thousands of years. Today, cats are one of the most popular pets in the world. In the U.S. alone, it is estimated that more than 31 million households have at least one. Join Britannica as we take a closer look at these furry friends.
Thinking About Getting a Kitten? Here’s Our List of the 10 Best Types of Cat
List / Science
© ivan kmit/stock.adobe.com
Podcasts
See All Shows And Podcasts
Botanize!
Botanize!, hosted by Melissa Petruzzello, is a podcast that will introduce you to some of the world’s most remarkable plants, fungi, and algae. These overlooked organisms have fascinating evolutionary stories to tell about survival, exploitation, adaptation, and general scrappiness, and every episode will pique your curiosity. From parasitic plants to kelp forests, Botanize! aims to showcase some of Earth’s finest nonanimal life-forms and their brilliant ecologies.

Postcards from the 6th Mass Extinction
So far there have been five notable mass extinctions on Earth. A growing number of scientists argue that we’re now in the midst of a sixth. Postcards from the 6th Mass Extinction is a podcast hosted by John P. Rafferty that attempts to personalize extinction, emphasizing the survival challenges that familiar forms of life currently face, while at the same time considering the pivotal roles they play in their own ecosystems.

On This Day
Hear the stories that propelled us to the present day through insights that lend perspective to our world with a nod to our own humanity. Britannica media editor Kurt Heintz, together with Emily Goldstein and Meg Matthias, is on a mission to spotlight poignant and noteworthy events for every day of the year.
Causes and Effects

The American Revolution
Costly wars in Europe and North America had drained British coffers, but the need for increased tax revenue placed the crown in conflict with an increasingly assertive patriot movement in the colonies.

World War I
A web of entangling alliances turned a struggle between the crumbling Austro-Hungarian empire and Serbian nationalists into a conflagration that claimed the lives of more than 20 million people.
Browse by Category

Entertainment and leisure activities have been a part of all cultures in one form or another since the ancient times, whether the activity in question involved participating in a dance performance, attending a Broadway show, going to a music festival, or watching a movie.
Featured
- Popular art
-
Another Musical Instruments Quiz
Do you know who invented the clarinet? What is Korea’s...
-
Singers, Musicians, Composers, and More Quiz
How broad is your musical knowledge? Can you go from...

Planet Earth contains some extraordinarily diverse environments, some of which are easily habitable and some not so much. In different areas of Earth, one might find sweltering deserts, dense tropical rainforests, or bone-chilling tundras. Each biome and habitat comes with its own selection of flora and fauna, and it may include physical features such as canyons, volcanoes, rivers, or caves. Human beings have built homes in many different environments, settling the area and organizing it into units such as cities, states, regions, and countries, each with its own points of interest. Shifting trends in human migration have resulted in a human geography that is profoundly different from that of centuries ago.
Featured
- Ancient Italic people
-
13 Iconic Buildings to Visit in New York City
Know before you go.
-
5 Buildings You Have to See in Chile
Know before you go.

The study of the human mind and body, how these function, and how they interact—not only with each other but also with their environment—has been of utmost importance in ensuring human well-being. Research on potential treatments and preventive medicine has expanded greatly with the development of modern medicine, and a network of disciplines, including such fields as genetics, psychology, and nutrition, aims to facilitate the betterment of our health.
Featured
-
SARS
pathology
-
The Human Body
You may know that the human brain is composed of two...
-
Characteristics of the Human Body
How many facial muscles are involved in speaking? How...

It's easy enough to agree that human beings all around the world have certain basic requirements that must be fulfilled in order to ensure their individual and collective well-being. History has shown us, however, that it's not so easy to form societies or communities that fulfill these requirements for all members. The fight over human and civil rights has persisted for hundreds of years and remains alive today, both within the borders of nations and on an international scale. It has led to large-scale social movements and reforms concerning issues such as suffrage, slavery, women's rights, racial discrimination, environmentalism, gay rights, and more.
Featured
-
Feminism
sociology
-
Women’s History: Famous Women of Paris
What Parisian was the first woman to head the IMF?...
-
Halloween
Trick-or-treat! Halloween is so much more than candy....

With the development of language, the human imagination has found a way to create and communicate through the written word. A literary work can transport us into a fictional, fantastic new world, describe a fleeting feeling, or simply give us a picture of the past through novels, poems, tragedies, epic works, and other genres. Through literature, communication becomes an art, and it can bridge and bond people and cultures of different languages and backgrounds.
Featured
- Persian literature
-
William Shakespeare: The Prose and the Playwright
Where is Shakespeare buried? Who says "Alas, poor Yorick"?...
-
An Odyssey of Grecian Literature
Who was Odysseus’s wife? What author wrote The...

Humans have long pondered not only how we came to be but also why we came to be. The earliest Greek philosophers focused their attention upon the origin and nature of the physical world; later philosophers have theorized about the nature of knowledge, truth, good and evil, love, friendship, and much more. Thus, philosophy involves a methodical assessment of any and all aspects of human existence and experience. The realms of philosophy and religion have sometimes intersected in conducting inquiries such as these. As with philosophy, the study of religion underscores how humankind has long speculated about its origins. The possibility of a higher being (or beings) to which livings things owe their existence has long captived human thought. Many religions also offer their own views on the nature of good and evil, and they may prescribe guidelines and judgment on different kinds of human behavior.
Featured
-
Islam
religion
-
The Axial Age: 5 Fast Facts
Enlighten yourself about a period of enlightenment.
-
Plants with Religious Meaning
Test your knowledge of sacred plants with this quiz.

The world today is divided territorially into more than 190 countries, each of which possesses a national government that claims to exercise sovereignty and seeks to compel obedience to its will by its citizens. Governments can be classified in any number of ways. For example, they might be classified by the number of rulers, thus distinguishing government by one (as in a monarchy or a tyranny) from government by the few (in an aristocracy or oligarchy) and from government by the many (as in a democracy). Governments can also be classified by mode of succession; for example, ascension to governmental leadership may follow the rules of hereditary succession, or it may be determined through elections or by force. Governments also vary in terms of the laws and rules of conduct that each political entity follows.
Featured
- Political system
-
20 Under 40: Young Shapers of the Future (Business and Entrepreneurship)
20 amazing young leaders changing the world.
-
20 Under 40: Young Shapers of the Future (Social Activism and Politics)
20 amazing young leaders changing the world.

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.
Featured
- History of science
-
Characteristics of Earth: Fact or Fiction?
Is it true that life can only evolve on Earth? From...
-
Microscopes and Telescopes: Fact or Fiction?
Is the Hubble Space Telescope named for a scientist?...

Physical contests and recreational games have long played a part in human society. In both team and solo sports, the human body has been pushed to its limits in the name of improving athletic performance and to break record upon record. The ancient Olympic Games are an early example of the contests in which humans have engaged to showcase physical prowess. In modern times, sports and games have evolved into a lucrative and competitive industry, while other leisure activities, such as card and video games, can be competitive or can just be a way to unwind or socialize.
Featured
-
chess
game
-
Is It Really Dangerous to Swim After Eating?
Aside from the sharks, that is.
-
Indianapolis 500 Quiz
Think you know everything about the Greatest Spectacle...

Humankind has long striven to improve its living conditions through the development of tools, instruments, and transportation and communications systems, all with the goal of making our lives easier, more productive and—why not—more fun, too! Thanks to human curiosity and technological research, many significant inventions have been made throughout history that in turn made a difference in our daily lives.
Featured
-
history of flight
aviation
-
Inventions Through History
What invention helped the Normans win the Battle of...
-
Save Hours Every Week and Up Your Marketability When You Master Microsoft Excel
How well do you really know the spreadsheet program...

These are the arts that meet the eye and evoke an emotion through an expression of skill and imagination. They include the most ancient forms, such as painting and drawing, and the arts that were born thanks to the development of technology, like sculpture, printmaking, photography, and installation art, the latter a combination of multiple creative expressions. Though beauty is in the eye of the beholder, different eras in art history have had their own principles to define beauty, from the richly ornamented taste of the Baroque to the simple, utilitarian style of the Prairie School.
Featured
- South Asian arts
-
7 Accomplished Paintings in Moscow
Learn before you look.
-
4 Notable Paintings in Norway and 1 in Sweden Depicting Norway
Learn before you look.

Does history really repeat itself, or can we learn from the mistakes of those who came before us? History provides a chronological, statistical, and cultural record of the events, people, and movements that have made an impact on humankind and the world at large throughout the ages. Investigating the causes and results of past events is critically important in gaining a full understanding and perspective of present-day issues.
Featured
-
American Revolution
United States history
-
Nero: Fact or Fiction?
Did Nero start the great fire of Rome? Why did Nero...
-
Spot the Difference: Pirates, Privateers, Corsairs, and Buccaneers
Ahoy, matey! Can you tell the difference between these...
More From Britannica
ProCon.org
Award-winning ProCon.org promotes critical thinking, education, and informed citizenship by presenting the pro and con arguments to controversial issues in a straightforward, nonpartisan, freely accessible way.
Britannica Beyond
Questions are an important way for people to learn concepts, to solve problems, and to challenge ideas. We’ve created a new place where questions are at the center of our learning. Go ahead. Ask. We won’t mind.
Advocacy for Animals
Presenting Advocacy for Animals, a blog focused primarily on animal rights, wildlife conservation, environmental health and safety, and the legal and cultural issues related to these topics. This blog is a source of information and a call to action. It is meant to be a provocation and a stimulus to thought regarding humanity’s relationship with nonhuman animals.
Alain Elkann Interviews
Alain has been writing a weekly interview column for the Italian newspaper La Stampa since 1989. His interviews celebrate some of the best known and successful personalities of the present day.