Railways are one of the most important inventions in modern history. From the 1825 opening of the Stockton and Darlington Railway in England, trains revolutionized both travel and trade and radically changed the way we experience the world. In the 24 richly illustrated lectures of How Railways Transformed the World, you’ll experience the amazing world and impact of railways, from the early 19th century to today’s futuristic trains, including extensive material on the pleasure and appeal of rail travel today.

The promise of America is that the country is based on an idea, one where everyone is created equal and equally free to chart their own course. From 13 newly independent states ratifying a national constitution to the heated debates in the halls of Congress today, American politics is about negotiation over what our country is—and where we are going.

Thought experiments are “what if” scenarios that invite us to look carefully at how we think and view the world. They’ve been used throughout history by philosophers and other thinkers to explore our intuitions and ways of reasoning, to find solutions to problems, and to expand our knowledge of ourselves and the world. In these 24 eye-opening lectures, Professor Breyer takes you deeply into the historical tradition of thought experiments, shining a light on both the purpose and the outcomes of these compelling mental voyages.

Heidi Sormaz has a PhD in psychology from Yale University with an emphasis on cognitive psychology, and she’s been a meditation and yoga practitioner and teacher for two decades. She is also a reformed over-thinker, so, she knows exactly what you’re going through—or what you’re (over)thinking, so to speak. Over the 12 engaging lessons of Overcome Your Overthinking, Heidi not only provides the science behind cognitive behavioral therapy but she’ll also arm you with a toolbox of exercises and techniques that are most effective at breaking the spell of overthinking.

Though it ended five centuries ago, the medieval era continues to permeate our world in far-reaching ways. Whether we pay attention to them or not, the influences and imprints of the Middle Ages are all around us, sometimes evident and sometimes less so. In these 36 revealing lectures, you’ll learn how to recognize the medieval impacts on the modern world, and to grasp their significance and implications. The Medieval Legacy offers you a deep look at a stunning millennium of change and innovation which continues to inform our contemporary world.

"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.

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.

Professor Allison Friederichs will walk you through six lessons that can help you better know your own mind, and thus understand and transform your own methods of communication. You will learn how your brain acquires, processes, and retains information. You can then take that knowledge and apply it whenever you need to convey something to others, with the best possible results. While you may not have any control over how other people communicate, developing your own methods of connection and conversation can have a positive impact on both your personal and professional life.

What is our species' greatest invention? Medicine, computers, space travel? Not even close. The innovation that underlies each of our past achievements and those we still aspire to is language. Language is the ultimate invention of Homo sapiens - one that has allowed us to change the physical and social world around us in every conceivable way, and an invention that has fundamentally changed us, as well.

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.