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.

"It doesn't take an Einstein to understand modern physics," says Professor Wolfson at the outset of these 24 lectures on what may be the most important subjects in the universe: relativity and quantum physics. Both have reputations for complexity. But the basic ideas behind them are, in fact, simple and comprehensible by anyone. These dynamic and illuminating lectures begin with a brief overview of theories of physical reality starting with Aristotle and culminating in Newtonian or "classical" physics.

To better put into perspective the various issues surrounding energy in the 21st century, you need to understand the essential science behind how energy works. And you need a reliable source whose focus is on giving you the facts you need to form your own educated opinions.

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.

Philosophers have long puzzled over the nature of space, time, and matter. These inquiries led to the flowering of physics with the Scientific Revolution in the 17th century. Since then, the spectacular success of modern physics might appear to have made philosophy irrelevant. But new theories have created a new range of philosophical concerns: What is the shape of space? Is time travel possible? Is there a grand unified theory that unites all of physics?

Nothing has had a more profound impact on the development of modern civilization than thermodynamics. Thermodynamic processes are at the heart of everything that involves heat, energy, and work, making an understanding of the subject indispensable for careers in engineering, physical science, biology, meteorology, and even nutrition and culinary arts. Get an in-depth tour of this vital and fascinating science in 24 enthralling lectures suitable for everyone from science novices to experts who wish to review elementary concepts and formulas.

No skill is more important in today's world than being able to think about, understand, and act on information in an effective and responsible way. What's more, at no point in human history have we had access to so much information, with such relative ease, as we do in the 21st century. But because misinformation out there has increased as well, critical thinking is more important than ever. These 24 rewarding lectures equip you with the knowledge and techniques you need to become a savvier, sharper critical thinker in your professional and personal life.

Language defines us as a species, placing humans head and shoulders above even the most proficient animal communicators. But it also beguiles us with its endless mysteries, allowing us to ponder why different languages emerged, why there isn't simply a single language, how languages change over time and whether that's good or bad, and how languages die out and become extinct.

Consider these commonly held scientific beliefs: Planetary orbits are fixed ellipses; we only use 10 percent of our brains; nothing travels faster than light; a thrown object’s trajectory is a parabola. They seem correct, but they’re all misconceptions that aren’t entirely accurate. There’s much more to the story than you think. These magnificent 24 lectures are devoted to busting myths, clearing up confusion, and giving you scientific epiphanies that could change how you think about your everyday world.

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."

To understand the roots of personality is to understand motivations and influences that shape behavior, which in turn reflect how you deal with the opportunities and challenges of everyday life. That's the focus of these exciting 24 lectures, in which you examine the differences in people's personalities, where these differences come from, and how they shape our lives. Drawing on information gleaned from psychology, neuroscience, and genetics, Professor Leary opens the door to understanding how personality works and why.

Hardly a day goes by that we don’t hear about someone committing a violent, reprehensible, even evil, act. And each time it happens, before we know anything about the circumstances, we are already sure of one thing: We are nothing like that perpetrator. But how can we be so sure? After all, we are all human. In Understanding the Dark Side of Human Nature, Professor Daniel Breyer takes us on a fascinating philosophical journey into many of the deepest and darkest questions that have engaged humanity for millennia.

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.

In this 24-lesson course aimed at non-scientists, noted particle physicist Dr. Don Lincoln of Fermi National Accelerator Laboratory covers more than a century of progress in physics, describing exactly how scientists reach the conclusions they do. He starts with the atom, which was long hypothesized but wasn’t definitively proven until a paper by Albert Einstein in 1905. That was just the beginning, as researchers probed ever deeper into the atom’s complex structure, leading to the weird findings of quantum mechanics.

In this 24-lesson course aimed at non-scientists, noted particle physicist Dr. Don Lincoln of Fermi National Accelerator Laboratory covers more than a century of progress in physics, describing exactly how scientists reach the conclusions they do. He starts with the atom, which was long hypothesized but wasn’t definitively proven until a paper by Albert Einstein in 1905. That was just the beginning, as researchers probed ever deeper into the atom’s complex structure, leading to the weird findings of quantum mechanics.

Economic forces are everywhere around you. But that doesn't mean you need to passively accept whatever outcome those forces might press upon you. Instead, with these 12 fast-moving and crystal clear lectures, you can learn how to use a small handful of basic nuts-and-bolts principles to turn those same forces to your own advantage.

For millennia, philosophers and scientists have been trying to unlock the secrets of the mind with only limited success—until now. Today, with modern technologies including the best in neuroscience, medical imaging, and recent advances in artificial intelligence, we are making more progress than ever before. In Introduction to Cognitive Science, Professor Thad A. Polk takes you on a fascinating tour of the latest discoveries in the relatively new field of cognitive science. In 24 exciting lectures, Professor Polk shares dozens of the most challenging questions in cognitive science today.

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.

"It doesn't take an Einstein to understand modern physics," says Professor Wolfson at the outset of these 24 lectures on what may be the most important subjects in the universe: relativity and quantum physics. Both have reputations for complexity. But the basic ideas behind them are, in fact, simple and comprehensible by anyone. These dynamic and illuminating lectures begin with a brief overview of theories of physical reality starting with Aristotle and culminating in Newtonian or "classical" physics.

From the 17th to 18th centuries, bold thinkers cast off the authority of ancient traditions and embraced reason as the primary tool for understanding the world. These rationalists, or early modern philosophers, included René Descartes, Baruch Spinoza, and Gottfried Wilhelm Leibniz—visionaries whose answers to profound questions remain relevant today. Early Modern Philosophy: Descartes and the Rationalists covers the key philosophers of this period in 12 fascinating half-hour lectures, presented by award-winning teacher James D. Reid, Professor of Philosophy at Metropolitan State University.

Are we alone in the universe? This is one of the most profound issues facing mankind - and one of the unresolved questions that science may finally be able to answer in this century. These 24 mind-expanding lectures reveal the cutting-edge research leading scientists to believe that life is not exclusively the domain of Earth. Professor Close offers an unparalleled look at the subject of life and the mysteries that remain.

The Vikings evoke striking images of horned helmets, battle axes, and merciless coastal raids. Remembered for their shocking brutality and impressive naval prowess, these marauding pirates from the North have inspired poetry, fantasy novels, plays, symphonies, and even comic book heroes over the last 12 centuries. But do any of these enduring tropes reflect reality? Who were the Vikings really? What do we know about the period that bears their name? Explore these questions and more in The Viking Age, a 12-lecture course that corrects the record on a transformative period in world history.

Philosophers have long puzzled over the nature of space, time, and matter. These inquiries led to the flowering of physics with the Scientific Revolution in the 17th century. Since then, the spectacular success of modern physics might appear to have made philosophy irrelevant. But new theories have created a new range of philosophical concerns: What is the shape of space? Is time travel possible? Is there a grand unified theory that unites all of physics?

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.

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.

Thor, Odin, Loki, Freyja, the Valkyries, Valhalla, Ragnarok — many of the places we encounter these and other names, places, and events from Norse mythology in daily life and pop culture are connected to the medieval sources in name only.

In a field known for startling ideas, the Many-Worlds Interpretation (MWI) of quantum mechanics may take the prize. It holds that parallel to our own world are a large number of other universes, almost identical to ours but with small variations. Copies of each of us inhabit a myriad of these worlds. But they are not us exactly; they share our past history, but they are different people who have unique futures. Although these realms are invisible and can’t communicate with each other, prominent physicists are convinced they must exist.

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.