Understanding our humanity - the essence of who we are - is one of the deepest mysteries and biggest challenges in modern science. Why do we have bad moods? Why are we capable of having such strange dreams? How can metaphors in our language hold such sway on our actions? As we learn more about the mechanisms of human behavior through evolutionary biology, neuroscience, anthropology, and other related fields, we're discovering just how intriguing the human species is.

 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.  

"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. After that, you'll follow along as Professor Wolfson outlines the logic that led to Einstein's profound theory of special relativity and the simple yet far-reaching insight on which it rests. With that insight in mind, you'll move on to consider Einstein's theory of general relativity and its interpretation of gravitation in terms of the curvature of space and time.From there, you'll embark on a dazzling exploration of how inquiry into matter at the atomic and subatomic scales led to quandaries that are resolved-or at least clarified-by quantum mechanics, a vision of physical reality so profound and so at odds with our experience that it nearly defies language.By bringing relativity and quantum mechanics into the same picture, you'll chart the development of fascinating hypotheses about the origin, development, and possible futures of the entire universe, as well as the possibility that physics can produce a "theory of everything" to account for all aspects of the physical world. But the goal throughout these lectures remains the same: to present the key ideas of modern physics in a way that makes them clear to the interested layperson.

Professor John McWhorter of Columbia University takes you back through time and around the world, following the linguistic trails left by generations of humans that lead back to the beginnings of language. Utilizing historical theories and cutting-edge research, these 34 astonishing lectures will introduce you to the major language families of the world and their many offspring, including a variety of languages that are no longer spoken but provide vital links between past and present. 

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.

Imagine a world without bees, butterflies, and flowering plants. That was Earth 125 million years ago. Turn back the clock 400 million years, and there were no trees. At 450 million years in the past, even the earliest insects had not yet developed. And looking back 500 million years, the land was devoid of life, which at that time flourished in a profusion of strange forms in the oceans. These and other major turning points are the amazing story of evolution.

Charles Darwin's theory of organic evolution-the idea that life on earth is the product of purely natural causes, not the hand of God-set off shock waves that continue to reverberate through Western society, and especially the United States. What makes evolution such a profoundly provocative concept, so convincing to most scientists, yet so socially and politically divisive? These 12 eye-opening lectures are an examination of the varied elements that so often make this science the object of strong sentiments and heated debate.

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.

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.

Your nervous system is you. All the thoughts, perceptions, moods, passions, and dreams that make you an active, sentient being are the work of this amazing network of cells. For many centuries, people knew this was true. But no one was sure how it happened. Now, thanks to the exciting new field of neuroscience, we can chart the workings of the brain and the rest of the nervous system in remarkable detail to explain how neurons, synapses, neurotransmitters, and other biological processes produce all the experiences of everyday life, in every stage of life.  

Since the publication in 1859 of Charles Darwin's remarkable On the Origin of Species, the modern science of biology and genetics has added surprising new dimensions to evolutionary theory. In this course, you’ll discover what Darwin didn’t know, covering much of the curriculum of an introductory college course in evolutionary biology. No background in science is needed to follow these engaging lectures, delivered by Professor Scott Solomon of Rice University, a gifted teacher and widely traveled field biologist.

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.

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.

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.