مؤلف: Sherman Hollar

The sub-zero temperatures and glacial conditions to which the polar regions of the Earth are often subject would make it difficult for many of us to survive there for long periods of time. Yet life i …

Perhaps the most prominent elements in the patchwork pattern formed by Earth’s regions and ecosystems are its deserts, grasslands, and rainforests. Though vastly different from one another and often …

Even though a growing number of people have begun to consider the impact of their actions on the environment, the planet remains vulnerable to human activity and the byproducts of modern conveniences …

Life on Earth can be viewed as a complex network of interactions between living organisms and their respective environments. By parsing the natural world into various ecosystems and biomes, the exten …

Although industrialization and modernization have dramatically improved the quality of our lives, they have also largely contributed to the destruction of our natural resources by engendering waste a …

Drawing crowds for its displays of both raw athleticism and spectacular showmanship, basketball has become one of the most exciting spectator sports in the United States, as well as the world. Player …

Despite their proximity to Earth, much remains to be learned about the origins and conditions of Mercury, Venus, and Mars. The three smallest planets in our solar system and the three closest to the …

Formalizing study of the natural world may seem like a daunting task considering the sheer breadth and variety of living things that inhabit the planet. From the microscopic organisms in the world’s …

With a following that remains unmatched by any other sport, soccer has commanded the loyalties of peoples of all backgrounds around the world, stirring the passions of all. National associations in c …

As our ability to observe space improves with ever-progressing technology, we better grasp the farthest reaches of the cosmos and heighten our understanding of the universe in its entirety. Spacecraf …

Fathoming the boundlessness of space and the universe, we are immediately filled with curiosity about our own origins and wonder about the objects, life forms, and matter that populate the cosmos. Th …

The iconic pyramids and striking hieroglyphics of ancient Egypt are but a limited representation of the resplendent culture that once inhabited the Nile Valley. The ancient Egyptians developed sophis …

Responsible for the first writing system and home to elaborate kingdoms and societies, Mesopotamia has been aptly labeled as the birthplace of the world’s first advanced civilizations. Although much …

For many of us, plants herald the change of seasons, represent the promise of nourishment, or serve as stunning visual reminders of Earth’s natural beauty. As vital components of nearly every ecosyst …

Distinguished by their highly developed mental faculties and their capacity for reason, humans are often said to reign sovereign in the animal kingdom. With their complex interactions, intricate soci …

Bacteria, algae, and protozoa-microorganisms that are easily overlooked in our daily lives-can be found in a wide variety of locations and serve innumerable ecological purposes. While some such organ …

Religious freedom, economic security, and the allure of a second chance drew thousands of settlers away from their European homeland to the shores of what would one day become the United States. Unde …

In the wake of the American Revolution, the United States of America was faced with the task of evolving into an independent republic This move was facilitated by a number of visionaries who rose to …

Nowhere can intricacies of the ideological, regional, and economic tensions that erupted into the American Civil War be better seen than in the individual actors who fought both on and off the battle …

Although most people would scarcely be able to make it through the day without using some type of electronic device-computers, televisions, and MP3 players, to name a few-the inner workings of such d …

Battling disease, championing new techniques, recommending necessary medications, and offering comfort and guidance to those in need are just some of the many responsibilities with which healers over …

Sometimes fickle and often devastating in its most extreme forms, the weather can seem inscrutable. Yet our understanding of weather systems and climate has improved greatly over the years due to the …

Rapidly developing technological innovation and mass production have become such hallmarks of our industrialized world that we may fail to consider the events and individuals that laid the groundwork …

Sound has the power to soothe, excite, warn, protect, and inform. Indeed, the transmission and reception of audio signals pervade our daily lives. Readers will examine the mechanics and properties of …

The seventh president of the United States, Andrew Jackson is often remembered for his "firsts"; he was the first leader from west of the Appalachians and the first to win office by directl …

Sweeping into the office of U.S. president with his mesmerizing oratory of hope and change, Barack Obama forever transformed American politics. As the first African American to hold the title, his el …

Although more than 200 years have passed since the death of the first U.S. president, the name George Washington still invokes deep patriotism and pride in the country he helped found. A leader on th …

Though he had less than three years in office, John F. Kennedy made a lasting and profound mark as U.S. president. Deftly handling the Cuban Missile Crisis and supporting civil rights laws and the sp …