This is one of the most unique and spectacular and exhilarating books I have ever read. Brian’s lucid explanations of time, space, the quantum world, religious beliefs, cave paintings, the end of the universe, various great physicists, Einstein, Newton, the centrality of mathematics— I could go on and on. His ability to make complex issues understandable is truly a gift. His occasional excursions into his own life experiences are delightful. The scope of his knowledge is breathtaking🌪️. His warmth and insights are palpable. His philosophical ruminations are insightful and acknowledge the tragedy and beauty of our knowledge of our own impermanence. And a central point of this book is that the universe is impermanent too📼. Please read this exquisite book. A work of mind-expanding genius.