Three of the most important words in science are I don't know. Not knowing implies a universe of opportunities—the possibility of discovery and surprise. Our understanding of science has advanced immeasurably over the last 500 years, yet many fundamental mysteries of existence persist: How did our universe begin? How big is the universe? Is time travel possible? What’s at the center of a black hole? How did life on Earth arise? Are we alone? What is consciousness, and can we create it?

The story of our world and the different living things that have populated it is an amazing epic with millions of species, exotic settings, planet-wide cataclysms, and surprising plot twists. These 36 lectures tell the all-embracing story of life on Earth - its origins, extinctions, and evolutions - in a manner that assumes no background in science. At half an hour per lecture, you’ll cover the entire 4.54-billion-year history of Earth in 18 hours, averaging 70,000 years per second!

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.

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 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.

The Roman Empire: From Augustus to the Fall of Rome traces the breathtaking history from the empire’s foundation by Augustus to its Golden Age in the 2nd century CE through a series of ever-worsening crises until its ultimate disintegration. Taught by acclaimed Professor Gregory S. Aldrete of the University of Wisconsin-Green Bay, these 24 captivating lectures offer you the chance to experience this story like never before, incorporating the latest historical insights that challenge our previous notions of Rome’s decline.  

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.

Mercury, a lifeless victim of the Sun’s expanding power. Venus, once thought to be lush and fertile, now known to be trapped within a toxic and boiling atmosphere. Mars, the red planet, doomed by the loss of its atmosphere. Jupiter, twice the size of all the other planets combined, but insubstantial. Saturn, a stunning celestial beauty, the jewel of our Solar System. Uranus, the sideways planet and the first ice giant. Neptune, dark, cold and whipped by supersonic winds. Pluto, the dwarf planet, a frozen rock. 

 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.  

In 20 captivating lectures, Professor Suzanne Pilaar Birch shares her expertise and passion for discovery as she peels back the years to expose the emergence and lives of early humans. You will learn about their environmental challenges, the methods they used to meet their basic needs, cultural development, and the fascinating advances in our own technologies that have allowed us to take their few physical remains and develop a much fuller picture.

Welcome to the Universe is a personal guided tour of the cosmos by three of today's leading astrophysicists. Inspired by the enormously popular introductory astronomy course that Neil deGrasse Tyson, Michael A. Strauss, and J. Richard Gott taught together at Princeton, this book covers it all - from planets, stars, and galaxies to black holes, wormholes, and time travel.

For decades, beloved astrophysicist Neil deGrasse Tyson has interpreted science with a combination of brainpower and charm that resonates with fans everywhere. This pioneering, provocative audiobook brings together the best of StarTalk, his beloved podcast and television show devoted to solving the most confounding mysteries of Earth, space, and what it means to be human. 

Are there other dimensions beyond our own? Is time travel possible? Can we change the past? Are there gateways to parallel universes? All of us have pondered such questions, but there was a time when scientists dismissed these notions as outlandish speculations. Not any more. Today, they are the focus of the most intense scientific activity in recent memory. In Hyperspace, Michio Kaku offers the first book-length tour of the most exciting (and perhaps most bizarre) work in modern physics.

It is difficult to conceive of the vast scale of the history of life on Earth, from the very first living organisms sparking into life in hydrothermal deep-sea vents to the dizzying diversity of life today. The evolution of life is a sweeping epic of a tale, with twists and turns, surprising heroes and unlikely survivors. The Earth beautifully distils this complex story into a meaningful scale. In taking a closer look at 47 carefully selected organisms over 15 periods in our planetary history, this audiobook tells the whole story of life on Earth.

With a foreword from Professor Brian Cox and access to all the latest NASA mission information, Andrew Cohen takes listeners on a voyage of discovery via the probes and telescopes exploring the outer reaches of our galaxy, revealing how it was formed and how it will inevitably be destroyed by the enigmatic black hole at its heart. And beyond our galaxy, the expanding universe, which holds clues to the biggest mystery of all - how did it all begin?