霍金在生前发表的最后一篇论文中提出了自上而下的新宇宙学，颠覆了他在《时间简史》中提出的关于时间起源的观点，本书作者托马斯·赫托格正是这篇论文的合著者。在这篇刊登在《高能物理学杂志》上的文章中，他们认为多元宇宙并没有那么多，宇宙的演化在整体上是平滑而有限的。
霍金在他非凡的一生中试图回答，宇宙是如何创造出如此完美且适宜生命生存的环境的？为了解开这个谜团，霍金研究了宇宙的大爆炸起源，但他的早期工作遇到了危机，因为他的数学预测结果显示，在可能产生的所有宇宙中，占最大比例的宇宙种类是无法孕育出生命的。
Perhaps the biggest question Stephen Hawking tried to answer in his extraordinary life was how the universe could have created conditions so perfectly hospitable to life. In order to solve this mystery, Hawking studied the big bang origin of the universe, but his early work ran into a crisis when the math predicted many big bangs producing a multiverse—countless different universes, most of which would be far too bizarre to harbor life.
Holed up in the theoretical physics department at Cambridge, Stephen Hawking and his friend and collaborator Thomas Hertog worked on this problem for twenty years, developing a new theory of the cosmos that could account for the emergence of life. Peering into the extreme quantum physics of cosmic holograms and venturing far back in time to our deepest roots, they were startled to find a deeper level of evolution in which the physical laws themselves transform and simplify until particles, forces, and even time itself fades away. This discovery led them to a revolutionary idea: The laws of physics are not set in stone but are born and co-evolve as the universe they govern takes shape. As Hawking’s final days drew near, the two collaborators published their theory, which proposed a radical new Darwinian perspective on the origins of our universe.
