Great Throughts Treasury

"That multiverse idea is not a notion invented to account for the miracle of fine-tuning. It is a consequence of the no-boundary condition as well as many other theories of modern cosmology. But if it is true, then the strong anthropic principle can be considered effectively equivalent to the weak one, putting the fine-tunings of physical law on the same footing as the environmental factors, for it means that our cosmic habitat?now the entire observable universe?is only one of many, just as our solar system is one of many. That means that in the same way that the environmental coincidences of our solar system were rendered unremarkable by the realization that billions of such systems exist, the fine-tunings in the laws of nature can be explained by the existence of multiple universes."

"The laws of M-theory therefore allow for different universes with different apparent laws, depending on how the internal space is curled. M-theory has solutions that allow for many different internal spaces, perhaps as many as 10500, which means it allows for 10500 different universes, each with its own laws. To get an idea how many that is, think about this: If some being could analyze the laws predicted for each of those universes in just one millisecond and had started working on it at the big bang, at present that being would have studied just 1020 of them. And that?s without coffee breaks."

"The Greeks? Christian successors rejected the idea that the universe is governed by indifferent natural law. They also rejected the idea that humans do not hold a privileged place within that universe. And though the medieval period had no single coherent philosophical system, a common theme was that the universe is God?s dollhouse, and religion a far worthier study than the phenomena of nature. Indeed, in 1277 Bishop Tempier of Paris, acting on the instructions of Pope John XXI, published a list of 219 errors or heresies that were to be condemned. Among the heresies was the idea that nature follows laws, because this conflicts with God?s omnipotence. Interestingly, Pope John was killed by the effects of the law of gravity a few months later when the roof of his palace fell in on him."

"The philosopher John W. Carroll compared the statement All gold spheres are less than a mile in diameter to a statement like All uranium-235 spheres are less than a mile in diameter. Our observations of the world tell us that there are no gold spheres larger than a mile wide, and we can be pretty confident there never will be. Still, we have no reason to believe that there couldn?t be one, and so the statement is not considered a law. On the other hand, the statement All uranium-235 spheres are less than a mile in diameter could be thought of as a law of nature because, according to what we know about nuclear physics, once a sphere of uranium-235 grew to a diameter greater than about six inches, it would demolish itself in a nuclear explosion. Hence we can be sure that such spheres do not exist. (Nor would it be a good idea to try to make one!) This distinction matters because it illustrates that not all generalizations we observe can be thought of as laws of nature, and that most laws of nature exist as part of a larger, interconnected system of laws."

"The Ionian idea that the universe is not human-centered was a milestone"

"The most incomprehensible thing about the universe is that it is comprehensible. ?ALBERT EINSTEIN"

"The true miracle is that abstract considerations of logic lead to a unique theory that predicts and describes a vast universe full of the amazing variety that we see."

"There might be one history in which the moon is made of Roquefort cheese. But we have observed that the moon is not made of cheese, which is bad news for mice. Hence histories in which the moon is made of cheese do not contribute to the present state of our universe, though they might contribute to others. That might sound like science fiction, but it isn?t."

"The universe expanded by a factor of 1,000,000,000,000,000,000,000,000,000,000 in .00000000000000000000000000000000001 second. It was as if a coin 1 centimeter in diameter suddenly blew up to ten million times the width of the Milky Way."

"Until the advent of modern physics it was generally thought that all knowledge of the world could be obtained through direct observation, that things are what they seem, as perceived through our senses. But the spectacular success of modern physics, which is based upon concepts such as Feynman?s that clash with everyday experience, has shown that that is not the case. The naive view of reality therefore is not compatible with modern physics."

"We create history by our observation, rather than history creating us."

"Traditionally these are questions for philosophy, but philosophy is dead. Philosophy has not kept up with modern developments in science, particularly physics. Scientists have become the bearers of the torch of discovery in our quest for knowledge."

"We create models in science, but also in everyday life. Model-dependent realism applies not only to scientific models, and mental models that we create all know, conscious or subconscious level, to interpret and understand the world every day. We cannot eliminate observer - ourselves - from our perception of the world, obtained by processing sensory perception and the way we think and rational. Our perception - and hence the observations which underpins our theories - not directly, but is adjusted by a kind of lens, interpretive structure of the human brain."

"We believe human begins have existed for only a small fraction of cosmic history, because human race has been improving so rapidly in knowledge and technology that if people had been around for millions of years, the human race would be much further along in its mastery."

"We are the product of quantum fluctuations in the very early universe. If one were religious, one could say that God really does play dice."

"Why is there something rather than nothing? Why do we exist? Why this particular set of laws and not some other? This is the Ultimate Question of Life, the Universe and Everything. We shall attempt to answer it in this book. Unlike the answer given in The Hitchhiker?s Guide to the Galaxy, ours won?t be simply ?42?."