James Holt has a new book called Why Does the World Exist? This is culled from Dyson's review of it in the NYT.
The antithesis of John Leslie is David Deutsch, whose book The Beginning of Infinity I recently reviewed in these pages. Holt visited Deutsch at his home in a village a few miles from Oxford. The chapter describing the visit is entitled “The Magus of the Multiverse.” Deutsch is a professional physicist who uses physics as a basis for philosophical speculation. Unlike most philosophers, he understands quantum mechanics and feels at home in a quantum universe. He likes the many-universe interpretation of quantum mechanics, invented in the 1950s by Hugh Everett, who was then a student in Princeton. Everett imagined the quantum universe as an infinite assemblage of ordinary universes all existing simultaneously. He called the assemblage the multiverse.
The essence of quantum physics is unpredictability. At every instant, the objects in our physical environment—the atoms in our lungs and the light in our eyes—are making unpredictable choices, deciding what to do next. According to Everett and Deutsch, the multiverse contains a universe for every combination of choices. There are so many universes that every possible sequence of choices occurs in at least one of them. Each universe is constantly splitting into many alternative universes, and the alternatives are recombining when they arrive at the same final state by different routes. The multiverse is a huge network of possible histories diverging and reconverging as time goes on. The “quantum weirdness” that we observe in the behavior of atoms, the “spooky action at a distance” that Einstein famously disliked, is the result of universes recombining in unexpected ways.
According to Deutsch, each of us exists in the multiverse as a crowd of almost identical creatures, traveling together through time along closely related histories, splitting and recombining constantly like the atoms of which we are composed. He does not claim to have an answer to the question “Why does the multiverse exist?” or to the easier question “What is the nature of consciousness?” He sees ahead of us a long future of slow exploration, answering philosophical questions that we do not yet know how to ask. One of the questions that we know how to ask but not to answer is: “Does quantum computing play an essential role in our consciousness?” For Deutsch, the physics of quantum computing is the most promising clue that may lead us to a deeper understanding of our existence. He theorizes, Holt tells us, that “all the different parallel universes in the multiverse” could “be coaxed into collaborating on a single computation.”
My favorite version of the multiverse is a story told by the philosopher Olaf Stapledon, who died in 1950. He taught philosophy at the University of Liverpool. In 1937 he published a novel, Star Maker, describing his vision of the multiverse. The book was marketed as science fiction, but it has more to do with theology than with science. The narrator has a vision in which he travels through space visiting alien civilizations from the past and the future, his mind merging telepathically with some of their inhabitants who join him on his journey. Finally, this “cosmical mind” encounters the Star Maker, an “eternal and absolute spirit” who has created all of these worlds in a succession of experiments. Each experiment is a universe, and as each experiment fails he learns how to design the next experiment a little better. His first experiment is a simple piece of music, a rhythmic drumbeat exploring the texture of time. After that come many more works of art, exploring the possibilities of space and time with gradually increasing complexity.
Our own universe comes somewhere in the middle, a big improvement on its predecessors but still destined for failure. Its flaws will bring it to a tragic end. Far outside the range of our understanding will be the later experiments, avoiding the mistakes that the Star Maker made with our own universe, and leading the way to ultimate perfection. Stapledon’s multiverse, conceived in the shadow of the approaching horrors of World War II, is an imaginative attempt to grapple with the problem of good and evil.
The essence of quantum physics is unpredictability. At every instant, the objects in our physical environment—the atoms in our lungs and the light in our eyes—are making unpredictable choices, deciding what to do next. According to Everett and Deutsch, the multiverse contains a universe for every combination of choices. There are so many universes that every possible sequence of choices occurs in at least one of them. Each universe is constantly splitting into many alternative universes, and the alternatives are recombining when they arrive at the same final state by different routes. The multiverse is a huge network of possible histories diverging and reconverging as time goes on. The “quantum weirdness” that we observe in the behavior of atoms, the “spooky action at a distance” that Einstein famously disliked, is the result of universes recombining in unexpected ways.
According to Deutsch, each of us exists in the multiverse as a crowd of almost identical creatures, traveling together through time along closely related histories, splitting and recombining constantly like the atoms of which we are composed. He does not claim to have an answer to the question “Why does the multiverse exist?” or to the easier question “What is the nature of consciousness?” He sees ahead of us a long future of slow exploration, answering philosophical questions that we do not yet know how to ask. One of the questions that we know how to ask but not to answer is: “Does quantum computing play an essential role in our consciousness?” For Deutsch, the physics of quantum computing is the most promising clue that may lead us to a deeper understanding of our existence. He theorizes, Holt tells us, that “all the different parallel universes in the multiverse” could “be coaxed into collaborating on a single computation.”
My favorite version of the multiverse is a story told by the philosopher Olaf Stapledon, who died in 1950. He taught philosophy at the University of Liverpool. In 1937 he published a novel, Star Maker, describing his vision of the multiverse. The book was marketed as science fiction, but it has more to do with theology than with science. The narrator has a vision in which he travels through space visiting alien civilizations from the past and the future, his mind merging telepathically with some of their inhabitants who join him on his journey. Finally, this “cosmical mind” encounters the Star Maker, an “eternal and absolute spirit” who has created all of these worlds in a succession of experiments. Each experiment is a universe, and as each experiment fails he learns how to design the next experiment a little better. His first experiment is a simple piece of music, a rhythmic drumbeat exploring the texture of time. After that come many more works of art, exploring the possibilities of space and time with gradually increasing complexity.
Our own universe comes somewhere in the middle, a big improvement on its predecessors but still destined for failure. Its flaws will bring it to a tragic end. Far outside the range of our understanding will be the later experiments, avoiding the mistakes that the Star Maker made with our own universe, and leading the way to ultimate perfection. Stapledon’s multiverse, conceived in the shadow of the approaching horrors of World War II, is an imaginative attempt to grapple with the problem of good and evil.
Opinions vary widely concerning the proper limits of science. For me, the multiverse is philosophy and not science. Science is about facts that can be tested and mysteries that can be explored, and I see no way of testing hypotheses of the multiverse. Philosophy is about ideas that can be imagined and stories that can be told. I put narrow limits on science, but I recognize other sources of human wisdom going beyond science. Other sources of wisdom are literature, art, history, religion, and philosophy. The multiverse has its place in philosophy and in literature.
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