The Accidental Universe: The World You Thought You Knew
“The Accidental Universe offers to the reader the wanderings of a curious and intelligent mind . . .”
[Disclaimer: Both the author and the reviewer are employed by MIT but neither knows each other nor do they work together.]
The Accidental Universe is not a physics book, holds no formulae, and is definitely not a consideration of what cosmology means. It is a consideration of what cosmology might mean.
Interwoven are the author’s philosophy on family, life and the passage of time—what it means to be human. Though reflection of this sort has been done many times before, there is always room for one more especially when by Alan Lightman, author of Einstein’s Dreams.
The first topic (one of many) that concerns the author is the multiverse, the possibility that number of universes can coexist simultaneously, possibly with different laws of physics. The multiverse makes a number of theoretical physicists unhappy as it implies the fundamental features of our universe are accidental with no hope of ever explaining our universe in terms of fundamental causes and principles.
As part of exploring the multiverse the author Interviews Alan Guth who was first to propose a period of inflation immediately after the Big Bang, as inflation leads to the theory of the multiverse. Dr. Lightman also interviews Garth Illingworth, a scientist who studies distant galaxies through images relayed from the Hubble Space Telescope.
A thread in this topic involves dark energy, an energy that comprises three quarters of the total energy in the universe. Though no one knows what dark energy is, it drives the expansion of the universe, something that also appears to be speeding up. Dark energy plays a part in the universe’s Anthropic Principle—the principle that the universe was tuned (dare I say it? designed) to enable life. Were any fundamental parameters of physics different, larger or smaller, life in the universe would have been impossible. If dark energy were greater, the expansion of the universe would have accelerated to where distances between atoms would have been so great as to prevent stars from forming. If the amount of dark energy were any less less, the Universe would have collapsed even before atoms could form.
The multiverse offers an explanation for our Universe that does not need an Anthropic Principle as it explains the problem of fine-tuning physical laws. With a multiverse, there might be an infinite number of universes, and so our universe is what it is because we are here. Though the Big Bang allows for a multiverse as does string theory, in neither is there experimental support. Accidental and incalculable, scientists must accept what they cannot prove—faith is something that goes against the grain of science.
Another topic of The Accidental Universe is the nature of change, change that occurs on the personal and the cosmic level. At the personal level, while Dr. Lightman goes about his life, to his surprise years pass. Not only does he wear out his favorite pair of shoes, but his daughter has the audacity to grow up and get married. So too on the cosmic level everything changes in the universe. Everything ages—even as stars are being born, at some point in the future stars will cease to be born.
Another topic of interest to the author concerns the relationship between religion and science. In the belief that the laws of nature protect us from the vagaries of the gods, Dr. Lightman asks such questions as, what are the boundaries between science and religion? Can science and religion co-exist? What is the nature of God? Has science made God irrelevant?
Borrowing from his previous book Mr. G, Dr. Lightman struggles against his inability to accept his inability to understand the universe. ”If some cosmic intelligence created the Universe, life would seem to be only an afterthought.” He looks for clues in the attributes of science and religion. In religion he finds two distinguishing characteristics that depend on faith, and as they depend on faith are question-limiting—these are transcendental experience and sacred books.
He also identifies one question-limiting characteristic of science: that scientists only select to solve well-posed problems. He considers the value of ambiguity, in exploring questions that science cannot (yet) answer. Dr. Lightman asks if science ever accept beliefs without proof (as does religion) and finds that science indeed does, first in the belief that the laws of nature are ultimately discoverable, and second that the physical laws of nature hold true everywhere. And it just so happens that these are the very-same beliefs being strained by the possibility of the multiverse.
Dr. Lightman also explores the nature of the human mind. The physicist in him expects the mind to be predictable as the laws of physics but he finds unpredictability and does not understand why. He points out another paradox, that the tools we use to extend our perception (to make new discoveries) can also disconnect us from reality. And he feels not so much distraction brought about by new inventions as he does cultural dislocation, that the young adapt more readily than the old to new things, rediscovering the human condition that many of us already know as the generation gap.
The Accidental Universe offers to the reader the wanderings of a curious and intelligent mind, a philosophical tour of recent and puzzling cosmological discoveries—from the nature of the Universe, to the nature of mankind.