Written by famous physicist and intellectual icon Stephen Hawking, and published in 2001, The Universe in a Nutshell is a sequel to Hawking’s previous work A Brief History of Time. In it, Hawking brings his readers up to date with the latest breakthroughs in theoretical physics, explaining complex theories in plain, simple, conversational language, and with humor. Hawking, who was born with motor neurone disease, which left him completely paralyzed, is considered to be one of the greatest physicists who has ever lived.

The Universe in a Nutshell is divided into seven chapters. In chapter 1, Hawking explains Einstein’s Special Theory of Relativity (1905) and his General Theory of Relativity (1915) and how Einstein transformed the way the universe was viewed. He also addresses Einstein’s association with the creation of the atomic bomb:

Some people have blamed the atomic bomb on Einstein because he discovered the relationship between mass and energy; but that is like blaming Newton for causing airplanes to crash because he discovered gravity. Einstein himself took no part in the Manhattan Project and was horrified by the dropping of the bomb.

In chapter 2, Hawking expands on Einstein’s theories and suggests ways in which they are linked to quantum mechanics and a discussion of time, explaining that “time has a shape.”

In chapter 3, he discusses the universe’s multiple histories, described by these theories, and the current work toward a unified “theory of everything” which will explain the entire cosmos. Chapter 4 moves into science fiction and looks forward to seeing whether the future can ever be predicted and, if so, whether black holes are a threat. In chapter 5, Hawking shifts from predicting the future to exploring the possibility of time travel. He suggests that in the future, traveling back to the past could be a possibility—a very, very small one.

I estimate the probability that Kip Thorne could go back and kill his grandfather as less than one in ten with a trillion trillion trillion trillion trillion zeroes after it.

Chapter 6 takes a look at the current speed of scientific and technological advancement and how this will affect the future of the human race. In chapter 7, the final chapter and the most complex, Hawking updates string theory with a discussion of p-brane theory. P-brane theory posits the idea that the entire universe is actually just a hologram. Hawking asks, “Do we live on a brane or are we just holograms?”

In The Universe in a Nutshell, Hawking discusses complicated subjects in accessible language. Each of the chapters can stand alone, and the book can, therefore, be read in any order.