Being a popular science book doesn’t mean this is beginner’s stuff nor you need to be a physicist to digest it.
However to get around comfortably you need to have consumed considerable hours digging other popular science books, or surfing Wikipedia on things like special relativity, general relativity, double-slit experiment, quantum physics, string theory, m-theory, and multiverses.
This book ties them up to a big picture and if you are lucky enough to be an open-minded person then you may have your ‘aha’ moment.
And your ‘aha’ moment may as well be the realization that god is not required to create the Universe, your dog, trees, the can of red-kidney beans on the kitchen table and everything else you see or you don’t see around you.
“The strong anthropic principle idea arose because it is not only the peculiar characteristics of our solar system that seem oddly conducive to development of human life but also the characteristics of our entire universe.”This book challenges the strong anthropic principle with the multiverse idea.
“The 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 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. Many people through the ages have attributed to God the beauty and complexity of nature that in their time seemed no scientific explanation. But just as Darwin and Wallace explained how the apparently miraculous design of living forms could appear without intervention by a supreme being, the multiverse concept can explain the fine-tuning of physical law without the need for a benevolent creator who made the universe for our benefit.”To some these may seem preposterous claims as no one witnessed evidence for multiverses. But our limited observation capacity is precisely the problem here. Multiverse idea is strongly linked to quantum theory. At quantum scales our observation interferes with the history of events selected. According to Feynman, a system has not just one history but every possible history.
“The histories that contribute to the Feynman sum don’t have an independent existence, but depend on what is being measured. We create history by our observation, rather than history creating us.
When one combines the general theory of relativity with quantum theory, the question of what happened before the beginning of the universe is rendered meaningless. The idea that histories should be closed surfaces without boundary is called the no-boundary condition.
We must accept that our usual ideas of space and time do not apply to the very early universe. That is beyond our experience, but not beyond our imagination, or our mathematics...One can also use Feynman’s methods to calculate the quantum possibilities for observations of the universe. If they are applied to the universe as a whole there is no point A (that it all started), so we add up all the histories that satisfy the no-boundary condition and end at the universe we observe today. In this view, the universe appeared spontaneously, starting off in every possible way. Most of these correspond to other universes. ”I thoroughly enjoyed reading this book I hope you too. It is exhilarating and full of trademark humor from Stephen Hawking.
Michael Shermer on Model Dependent Realism