Between 1861 and 1865, the clash of the greatest armies the Western hemisphere had ever seen turned small towns, little-known streams, and obscure meadows in the American countryside into names we will always remember. In those great battles, those streams ran red with blood-and the United States was truly born.

At the end of his career, Albert Einstein was pursuing a dream far more ambitious than the theory of relativity. He was trying to find an equation that explained all physical reality - a theory of everything. Experimental physicist and award-winning educator Dr. Don Lincoln takes you on this exciting journey in The Theory of Everything: The Quest to Explain All Reality. Suitable for the intellectually curious at all levels and assuming no background beyond basic high-school math, these 24 half-hour lectures cover recent developments at the forefront of particle physics and cosmology.

Look beyond the abstract dates and figures, kings and queens, and battles and wars that make up so many historical accounts. Over the course of 48 richly detailed lectures, Professor Garland covers the breadth and depth of human history from the perspective of the so-called ordinary people, from its earliest beginnings through the Middle Ages.

As recently as 1990, it seemed plausible that the solar system was a unique phenomenon in our galaxy. Thanks to advances in technology and clever new uses of existing data, now we know that planetary systems and possibly even a new Earth can be found throughout galaxies near and far.

England: From the Fall of Rome to the Norman Conquest takes you through the mists of time to the rugged landscape of the British Isles. Over the course of 24 sweeping lectures, Professor Jennifer Paxton of The Catholic University of America surveys the forging of a great nation from a series of warring kingdoms and migrating peoples. From Germanic tribes to Viking invasions to Irish missionaries, she brings to life an underexamined time and place.

Imagine a region in space where the force of gravity is so strong that nothing - not even light - can escape. This phenomenon is a black hole: one of the most exotic, mind-boggling, and profound subjects in astrophysics. Nearly everyone has heard of black holes, but few people outside of complex scientific fields understand their true nature and their implications for our universe. No movie, novel, or other fictional treatment of black holes matches Professor Filippenko’s absorbing presentation of the actual science behind these amazing objects.

Whether taken as a book of faith or a cultural artifact, the New Testament is among the most significant writings the world has ever known, its web of meaning relied upon by virtually every major writer in the last 2,000 years. Yet the New Testament is not only one of Western civilization’s most believed books, but also one of its most widely disputed, often maligned, and least clearly understood, with a vast number of people unaware of how it was written and transmitted.

Military history often highlights successes and suggests a sense of inevitability about victory, but there is so much that can be gleaned from considering failures. Study these crucibles of history to gain a better understanding of why a civilization took - or didn't take - a particular path.

Whether complete or only fragmentary, the 930 extant Dead Sea Scrolls irrevocably altered how we look at and understand the foundations of faith and religious practice. Now you can get a comprehensive introduction to this unique series of archaeological documents, and to scholars' evolving understanding of their authorship and significance, with these 24 lectures. Learn what the scrolls are, what they contain, and how the insights they offered into religious and ancient history came into focus.

Grasp the important ideas that have served as the backbone of philosophy across the ages with this extraordinary 60-lecture series. This is your opportunity to explore the enormous range of philosophical perspectives and ponder the most important and enduring of human questions-without spending your life poring over dense philosophical texts.

Gravity controls everything from the falling of an apple to the rising of ocean’s tides to the motions of the heavens above. If you’ve ever wondered how this most puzzling force works across our entire universe, you will be delighted by this 24-part course that is accessible to any curious person, regardless of your science education. No other product on the market presents the subject of gravity in as much detail as this course, which will follow the past 400 years of research and experimentation in the field.

Eating is an indispensable human activity. As a result, whether we realize it or not, the drive to obtain food has been a major catalyst across all of history, from prehistoric times to the present. Epicure Jean-Anthelme Brillat-Savarin said it best: "Gastronomy governs the whole life of man."

George Orwell was more than just a writer. He was a political and social sage who valued, above all else, individual freedom. His works aren’t just entertainment - they’re cautionary tales and red flags of warning. And if we ever hope to understand threats to freedom and how to stop them, we must learn from them. In these 24 lectures, learn how the man born as Eric Blair forged himself into a writer of international importance and renown.

What is life? What is my place in it? What choices do these questions obligate me to make? More than a half-century after it burst upon the intellectual scene - with roots that extend to the mid-19th century - Existentialism's quest to answer these most fundamental questions of individual responsibility, morality, and personal freedom, life has continued to exert a profound attraction.

My Big TOE: Awakening, written by a nuclear physicist in the language of contemporary culture, unifies science and philosophy, physics and metaphysics, mind and matter, purpose and meaning, the normal and the paranormal. The entirety of human experience (mind, body, and spirit) including both our objective and subjective worlds is brought together under one seamless scientific understanding.

Chemistry and Our Universe: How It All Works is your in-depth introduction to this vital field, taught through 60 engaging half-hour lectures that are suitable for any background or none at all. Covering a year’s worth of introductory general chemistry at the college level, plus intriguing topics that are rarely discussed in the classroom, this amazingly comprehensive course requires nothing more advanced than high-school math. Your guide is Professor Ron B. Davis, Jr., a research chemist and award-winning teacher at Georgetown University.

Richard Dawkins' brilliant reformulation of the theory of natural selection has the rare distinction of having provoked as much excitement and interest outside the scientific community as within it. His theories have helped change the whole nature of the study of social biology, and have forced thousands to rethink their beliefs about life.

How the Earth Works takes you on an astonishing journey through time and space. In 48 lectures, you will look at what went into making our planet - from the big bang, to the formation of the solar system, to the subsequent evolution of Earth.

We are in the midst of a global mental health crisis, and mental illnesses are on the rise. But what causes mental illness? And why are mental health problems so hard to treat? Drawing on decades of research, Harvard psychiatrist Dr. Chris Palmer outlines a revolutionary new understanding that for the first time unites our existing knowledge about mental illness within a single framework: mental disorders are metabolic disorders of the brain. Brain Energy will transform the field of mental health, and the lives of countless people around the world.

Astrophysicist Neil deGrasse Tyson has attracted one of the world’s largest online followings with his fascinating, widely accessible insights into science and our universe. Now, Tyson invites us to go behind the scenes of his public fame by unveiling his candid correspondence with people across the globe who have sought him out in search of answers. In this hand-picked collection of 100 letters, Tyson draws upon cosmic perspectives to address a vast array of questions about science, faith, philosophy, life, and of course, Pluto.

Hilarious, fascinating, and a roller coaster of dizzying, historical what-ifs, Napoleon's Hemorrhoids is a potpourri for serious historians and casual history buffs. In one of Phil Mason's many revelations, you'll learn that Communist jets were two minutes away from opening fire on American planes during the Cuban missile crisis, when they had to turn back as they were running out of fuel. You'll discover that before the Battle of Waterloo, Napoleon's painful hemorrhoids prevented him from mounting his horse to survey the battlefield.

Dr. Catherine Kleier invites us to open our eyes to the phenomenal world of plant life and to the process she calls “Natura Revelata”, the joy of celebrating and learning from the secrets of nature. As Dr. Kleier shares her knowledge with contagious excitement for her subject, she emphasizes the middle ground: Instead of focusing on cell microbiology or the study of ecosystems and habitats, she stresses the basic biology, function, and the amazing adaptations of the plants we see all around us.

In this illuminating audiobook, Tyson and coauthor James Trefil, a renowned physicist and science popularizer, take on the big questions that humanity has been posing for millennia - How did life begin? What is our place in the universe? Are we alone? - and provide answers based on the most current data, observations, and theories.

At the end of his career, Albert Einstein was pursuing a dream far more ambitious than the theory of relativity. He was trying to find an equation that explained all physical reality - a theory of everything. Experimental physicist and award-winning educator Dr. Don Lincoln takes you on this exciting journey in The Theory of Everything: The Quest to Explain All Reality. Suitable for the intellectually curious at all levels and assuming no background beyond basic high-school math, these 24 half-hour lectures cover recent developments at the forefront of particle physics and cosmology.

Between 1861 and 1865, the clash of the greatest armies the Western hemisphere had ever seen turned small towns, little-known streams, and obscure meadows in the American countryside into names we will always remember. In those great battles, those streams ran red with blood-and the United States was truly born.

Look beyond the abstract dates and figures, kings and queens, and battles and wars that make up so many historical accounts. Over the course of 48 richly detailed lectures, Professor Garland covers the breadth and depth of human history from the perspective of the so-called ordinary people, from its earliest beginnings through the Middle Ages.

What is life? What is my place in it? What choices do these questions obligate me to make? More than a half-century after it burst upon the intellectual scene - with roots that extend to the mid-19th century - Existentialism's quest to answer these most fundamental questions of individual responsibility, morality, and personal freedom, life has continued to exert a profound attraction.

With this exciting and historically rich six-lecture course, experience for yourself the drama of this dynamic year in medieval history, centered on the landmark Norman Conquest. Taking you from the shores of Scandinavia and France to the battlefields of the English countryside, these lectures will plunge you into a world of fierce Viking warriors, powerful noble families, politically charged marriages, tense succession crises, epic military invasions, and much more.

Grasp the important ideas that have served as the backbone of philosophy across the ages with this extraordinary 60-lecture series. This is your opportunity to explore the enormous range of philosophical perspectives and ponder the most important and enduring of human questions-without spending your life poring over dense philosophical texts.

George Orwell was more than just a writer. He was a political and social sage who valued, above all else, individual freedom. His works aren’t just entertainment - they’re cautionary tales and red flags of warning. And if we ever hope to understand threats to freedom and how to stop them, we must learn from them. In these 24 lectures, learn how the man born as Eric Blair forged himself into a writer of international importance and renown.

Why is Benjamin Franklin so compelling? What made him so successful in his day? And why has he continued to influence generations of Americans? Tackle these questions and more in The Age of Benjamin Franklin, a thorough - and sometimes surprising - course that presents a full portrait of a personality that defies easy definition.

Welcome to The Real History of Secret Societies, a historical look at the true-life groups which, if you believe the myths, are the unspoken power behind some of the world’s major turning points, from controlling the British crown to holding back the electric car and keeping Martians and Atlantis under wraps. Prepare yourself. In this course brought to you in partnership with HISTORY®, you will be visiting some of history’s deepest rabbit-holes, across centuries and continents, in search of secret societies in all their varieties.

Gravity controls everything from the falling of an apple to the rising of ocean’s tides to the motions of the heavens above. If you’ve ever wondered how this most puzzling force works across our entire universe, you will be delighted by this 24-part course that is accessible to any curious person, regardless of your science education. No other product on the market presents the subject of gravity in as much detail as this course, which will follow the past 400 years of research and experimentation in the field.

The Middle Ages was a time of major historical shifts and transformations. This amazing era reverberates with discoveries, innovations, events, and historical processes that are integral to the world we know now. In these 24 enthralling lectures, Professor Salisbury leads you on a sumptuous tour of this incredible historical epoch, making clear that the remarkable historical currents and advances of the Middle Ages unfolded not only in the West, but across the globe, from Europe, Africa, and the Middle East to Asia, the Americas, and beyond.