Everything we now know about the universe - from the behavior of quarks to the birth of galaxies - has come from people who've been willing to ponder the unanswerable. And with the advent of modern science, great minds have turned to testing and experimentation rather than mere thought as a way of grappling with some of the universe's most vexing dilemmas. So what is our latest picture of some of the most inexplicable features of the universe? What still remains to be uncovered and explored by today's scientists?

Astrophysicist Neil deGrasse Tyson has attracted one of the world’s largest online followings with his fascinating, widely accessible insights into science and our universe. Now, Tyson invites us to go behind the scenes of his public fame by unveiling his candid correspondence with people across the globe who have sought him out in search of answers. In this hand-picked collection of 100 letters, Tyson draws upon cosmic perspectives to address a vast array of questions about science, faith, philosophy, life, and of course, Pluto.

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.

In this illuminating audiobook, Tyson and coauthor James Trefil, a renowned physicist and science popularizer, take on the big questions that humanity has been posing for millennia - How did life begin? What is our place in the universe? Are we alone? - and provide answers based on the most current data, observations, and theories.  

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? 

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? 

Space and time form the very fabric of the cosmos. Yet they remain among the most mysterious of concepts. Is space an entity? Why does time have a direction? Could the universe exist without space and time? Can we travel to the past?

If you’ve ever wanted to delve more deeply into the mysteries of human emotion, perception, and cognition, and of why we do what we do, these 48 lectures offer a superb place to start. With them, you’ll see the entire history of psychology unfold. In the hands of Professor Robinson, these lectures encompass ideas, speculations, and point-blank moral questions that might just dismantle and rebuild everything you once thought you knew about psychology.

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.

 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.

In this fascinating foray into the centuries-old relationship between science and military power, acclaimed astrophysicist Neil deGrasse Tyson and writer-researcher Avis Lang examine how the methods and tools of astrophysics have been enlisted in the service of war. "The overlap is strong, and the knowledge flows in both directions", say the authors, because astrophysicists and military planners care about many of the same things: multi-spectral detection, ranging, tracking, imaging, high ground, nuclear fusion, and access to space. Tyson and Lang call it a "curiously complicit" alliance.

The science fiction genre has become increasingly influential in mainstream popular culture, evolving into one of the most engaging storytelling tools we use to think about technology and consider the shape of the future. Along the way, it has also become one of the major lenses we use to explore important philosophical questions. The origins of science fiction are most often thought to trace to Mary Shelley's novel Frankenstein, a story born from a night of spooky tale-telling by the fireside that explores scientific, moral, and ethical questions that were of great concern in the 19th century - and that continue to resonate today.

In a time of political and cultural polarization, Tyson provides a much-needed antidote to so much of what divides us, while making a passionate case for the twin chariots of enlightenment—a cosmic perspective and the rationality of science. Starry Messenger walks us through the scientific palette that sees and paints the world differently. From insights on resolving global conflict to reminders of how precious it is to be alive, Tyson reveals an array of brilliant and beautiful truths that apply to us all, enlightened by knowledge of our place in the universe.

Nothing has had a more profound impact on the development of modern civilization than thermodynamics. Thermodynamic processes are at the heart of everything that involves heat, energy, and work, making an understanding of the subject indispensable for careers in engineering, physical science, biology, meteorology, and even nutrition and culinary arts. Get an in-depth tour of this vital and fascinating science in 24 enthralling lectures suitable for everyone from science novices to experts who wish to review elementary concepts and formulas.