The Inexplicable Universe: Unsolved Mysteries

Here, take a closer look at concepts that were once unexplainable but, thanks to modern physics, are now better understood. You'll focus on two such former mysteries: the existence of an invisible "aether" through which light and sound were believed to travel and the orbit of Mercury, which seemed (to earlier scientists) to violate Newton's fundamental laws of motion.

Did you know that electrons, discovered in 1897, have never actually been observed by scientists? Or that quarks can only be studied in pairs? Or that as you travel faster or find yourself in a higher gravity, time ticks more slowly for you? Delve into these and other mind-warping facts and insights about the fundamentals of matter.

Why was Jupiter believed to be a good environment for life in the 17th century? Why is there only one "tree of life" on Earth instead of multiple ones? How do extremophiles help scientists study life's genesis? Could life have come to Earth from another planet? And what do we mean when we hope to find examples of life that is "intelligent"?

Among the many topics you'll learn about are: the discovery of more elements on the periodic table; muon neutrinos, tao particles, and the three regimes of matter; the secrets of string theory (which offers the hope of unifying all the particles and forces of physics); and even the hypothetical experience of traveling through a black hole.

Investigate some perplexing aspects of space that science has uncovered in the last half-century. Learn about the mysterious trajectory of the Pioneer spacecraft (known as the "Pioneer anomaly"). Explore two of the longest-standing problems in astrophysics: dark matter and dark energy. And even try to map the shape of space-time.

Take a fascinating trip through dimensions higher than our own. You'll discover how quantum physics and string theory have opened our eyes to the possibilities of quantum foam, the multiverse, antimatter, and tachyons. Also, join Dr. Tyson for a preview of the long-term fate of the universe (including the collision of galaxies, the burning out of stars, and the decay of orbits into black holes).