How did we get from the Big Bang to today's staggering complexity, in which seven billion humans are connected into networks powerful enough to transform the planet? And why, in comparison, are our closest primate relatives reduced to near-extinction? Big History creator David Christian gives the answers in a mind-expanding cosmological detective story told on the grandest possible scale. He traces how, during eight key thresholds, the right conditions have allowed new forms of complexity to arise, from stars to galaxies, Earth to homo sapiens, agriculture to fossil fuels. This last mega-innovation gave us an energy bonanza that brought huge benefits to mankind, yet also threatens to shake apart everything we have created. This global origin story is one that we could only begin to tell recently, thanks to the underlying unity of modern knowledge. Panoramic in scope and thrillingly told, Origin Story reveals what we learn about human existence when we consider it from a universal scale.

The stochastic gravitational-wave background (SGWB) is by far the most difficult source of gravitational radiation detect. At the same time, it is the most interesting and intriguing one. This book describes the initial detection of the SGWB and describes the underlying mathematics behind one of the most amazing discoveries of the 21st century. On the experimental side it would mean that interferometric gravitational wave detectors work even better than expected. On the observational side, such a detection could give us information about the very early Universe, information that could not be obtained otherwise. Even negative results and improved upper bounds could put constraints on many cosmological and particle physics models.