Time rules our lives, woven into the very fabric of the universe-from the rising and setting of the sun to the cycles of nature, the thought processes in our brains, and the biorhythms in our day. Nothing so pervades our existence and yet is so difficult to explain. But now, in a series of 24 riveting lectures, you can grasp exactly why - as you take a mind-expanding journey through the past, present, and future, guided by a noted author and scientist.

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.

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.

Would you like to know how the universe works? Scientists have been asking that question for a long time and have found that many of the answers can be found in the study of particle physics, the field that focuses on those impossibly tiny particles with unbelievably strange names - the hadrons and leptons, baryons and mesons, muons and gluons - so mystifying to the rest of us.

"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.

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.

Science is humanity's greatest achievement. It ranges from the study of the universe itself to the smallest particles of matter contained within it - and everything in between. If you want to better understand our physical world, as most of us do, gaining a basic understanding of science itself is profoundly important - yet many are intimidated by the breathtaking scope of such an endeavor. Now an award-winning science teacher has taken out the intimidation, harnessing that breathtaking scope into a series of 60 exciting, comprehensive, and accessible lectures.

 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.  

One of the greatest scientific feats of our era is the astonishing progress made in understanding biology-the intricate machinery of life-a progress to which the period we are living in right now has contributed the most.As you read these words, researchers are delving ever deeper into the workings of living systems, turning their discoveries into new medical treatments, improved methods of growing food, and innovative products that are already changing the world.

Dr. Catherine Kleier invites us to open our eyes to the phenomenal world of plant life and to the process she calls “Natura Revelata”, the joy of celebrating and learning from the secrets of nature. As Dr. Kleier shares her knowledge with contagious excitement for her subject, she emphasizes the middle ground: Instead of focusing on cell microbiology or the study of ecosystems and habitats, she stresses the basic biology, function, and the amazing adaptations of the plants we see all around us. 

Cut through the medical myths and get a solidly scientific guide to keeping yourself and your loved ones as protected as possible from pathogens, including a no-nonsense guide to vaccinations, tips on keeping a healthier home environment, and valuable advice for world travelers.

In the 24 engaging lectures of The Nature of Matter, no scientific background is needed to appreciate such miracles of everyday life as a bouncing rubber ball or water's astonishing power to dissolve. Moreover, the study of matter has led directly to such inventions as semiconductor circuits for computers, new fabrics for clothes, and powerful adhesives for medicine and industry.

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? 

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.  

We understand the stars at a much deeper level, not as legendary figures connected with constellations, but as engines of matter, energy, and the raw material of life itself. The Life and Death of Stars introduces you to this story in 24 half-hour lectures that lead you through the essential ideas of astrophysics - the science of stars. Your guide is Professor Stassun, an award-winning teacher and noted astrophysicist. He provides lively, eloquent, and authoritative explanations at a level suitable for science novices as well as for those who already know their way around the starry sky.