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.

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.

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.

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 these 24 lectures, The Great Courses teams up with the Smithsonian’s National Zoo and Conservation Biology Institute, to take you behind the scenes of the animal world. Dr. Moore has crafted a wonderful introduction to zoology that brings you up close and personal with a breathtaking variety of animal species through the eyes of a trained zoologist.

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.

"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.

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!

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.

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.

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.

One of the most complicated and advanced computers on Earth can't be purchased in any store. This astonishing device, responsible for storing and retrieving vast quantities of information that can be accessed at a moment's notice, is the human brain. How does such a dynamic and powerful machine make memories, learn a language, and remember how to drive a car? What habits can we adopt in order to learn more effectively throughout our lives? The answers to these questions are merely the tip of the iceberg in The Learning Brain.

The Science of Information: From Language to Black Holes covers the exciting concepts, history, and applications of information theory in 24 challenging and eye-opening half-hour lectures taught by Professor Benjamin Schumacher of Kenyon College. A prominent physicist and award-winning educator at one of the nation’s top liberal arts colleges, Professor Schumacher is also a pioneer in the field of quantum information, which is the latest exciting development in this dynamic scientific field. 

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.