The first two chapters of THE GRAND DESIGN lay out this view:
A quantum-informed understanding of the world is very different than a common sense understanding of the world. Unlike a common sense understanding of the world, a quantum understanding of the world can answer the big questions surrounding why there is a universe, with the laws it has, which make the seeming miracle of our existence possible. Given this claim, the rationales for belief in God that arise out of a common sense understanding of the world are obviated by a quantum-informed understanding of the world. The "space for God" once reserved by natural theology with its common sense view of reality has been eliminated.
As it pertains to the--supposedly now defunct--God question, that is the first two chapters of THE GRAND DESIGN in pure abstraction. Since the Hawking/Mlodinow approach was to give a brief overview based on their expert understanding, it is best for me to give you the bare abstraction and refer you to the book, if you wish to begin filling in a few details. Since I will in no way contest the science--just the conclusions drawn from it, aka, the Hawking/Mlodinow philosophical perspective--that is sufficient.
The just referenced "Hawking/Mlodinow philosophical perspective" implies that even if we grant to them that their quantum-informed science answers the big questions of the old common sense view of reality, there is a new field of metaphysical speculation opened up by their quantum science. Does anyone really think that we won't go meta on the new science and ask "is that all there is?" with respect to the understanding of the world wrought by the new physics?
Implicitly Hawking and Mlodinow address this question. For it is the need to close off this pretty obvious human tendency to "go meta" that they resort to a new form of that old chestnut, positivism: their "model-dependent realism."
The Grand Move
Model-dependent realism is the grand philosophical move in THE GRAND DESIGN. The argument for it is found in Chapter 3, "What Is Reality?"
Hawking and Mlodinow begin their exposition of model-dependent "reality" by making the point that a pet goldfish looking out from a frame of reference that begins with its transparent, spherical bowl would arrive at a different science--we're assuming that fish can do science--than someone outside the bowl. We might hope that the fish would arrive at a paradigm that allows it to think outside the bowl, but let's not spoil the point of the illustration: we are influenced by our means of observing the world, at least till we (via science) arrive at a better way to "see."
They begin with the illustration for an important reason. They want to establish that there is complete identity between what we think of as "reality" and our observation of it. To wit:
"According to model-dependent realism, it is pointless to ask whether a model is real, only whether it agrees with observation. If there are two models that agree with observation, like the goldfish's picture and ours, then one cannot say that one is more real than another." (46)
This follows from two things. First, the definition of model-dependent realism, and second, the claim that "There is no picture- or theory-independent concept of reality." (42)
Here's the definition:
"...model-dependent realism: the idea that a physical theory or world picture is a model (generally of a mathematical nature) and set of rules that connect the elements of the model to observations." (45)
Obviously, if there is no concept of reality apart from a model formed from a person's (or fish's) frame of reference, then reality simply IS what we perceive it to be--presumably it should be added, "in coherent moments where one's frame of reference is not distorted," i.e., we can't be on acid or be looking out from a place where our "fishbowl" has a crack or flaw in the glass.
Here's the crucial point--though it is never explicitly addressed in the book. It is incoherent to say of a false point of view that it is "real." For that reason, the Hawking/Mlodonow position must be that "If there are two models that agree with observation, like the goldfish's picture and ours, then one cannot say that one is more real than another." (46) For if model-dependent observations of the world are sometimes wrong, unbeknown to the person in the thrall of their frame of reference at a given time, then it must be allowed that Hawking and Mlodonow implicitly endorse a view by which--incoherently--they claim of a false point of view that it is real.
In my first post on this book, I expressed my frustration with the central use of model-dependent reality for this very incoherency. To buttress my opinion I cited Thomas Kuhn's comment below:
"Looking at the moon, the convert to Copernicanism [from a Ptolemaic frame of reference] does not say, 'I used to see a planet, but now I see a satellite.' That locution would imply a sense in which the Ptolemaic system had once been correct. Instead a convert to the new astronomy says, '...I was mistaken.'" (The Structure of Scientific Revolutions, Second Ed. (University of Chicago Press, 1970) 113-4.)
But in THE GRAND DESIGN the authors specifically take on the view that one frame of reference, or "model" of reality, can falsify another by disallowing the very point I had Kuhn make for me:
"So which is real, the Ptolemaic or Copernican system? Although it is not uncommon for people to say that Copernicus proved Ptolemy wrong, that is not true. As in the case of our normal view versus that of the goldfish, one can use either picture as a model of the universe, for our observations of the heavens can be explained by assuming either the earth or the sun to be at rest. Despite its role in philosophical debates over the nature of the universe, the real advantage of the Copernican system is simply that the equations of motion are much simpler..." (41-2)
Is it really that simple--just a choice between alternative realities based on which frame of reference is more convenient or, perhaps, familiar? No. In fact, the example can be clearly falsified, making Kuhn's point of view clearly true, and the Hawking/Mlodonow view clearly false.
Falsifying the Hawking/Mlodinow Grand Move
If one scientific frame of reference simply subsumes another--which is one way of construing the move from a Ptolemaic to a Copernican model of the universe--there is no contradiction between them, and both can be coherently called models of "reality," just as Hawking and Mlodinow wish us to do. But that is not the case, either here or with respect to the move from a Newtonian framework to an Einsteinian one, or from an Einsteinian one to the quantum-based framework in THE GRAND DESIGN. We will look at the falsification of the Ptolemaic model by the Copernican, since it is so simple to show (and it was the case used for purposes of illustration by Hawking/Mlodinow).
Assume just these two commonly known truths of "reality" that current science has confirmed for us: that the speed of light is constant in all frames of reference, and that we live in an amazingly vast cosmos, in which the nearest star to the Sun (Alpha Cantauri AB) is 4.37 light years away. Since a frame of reference in which the Sun goes around the Earth will include the third brightest star in the ski (Alpha Centauri AB) as part of the observational backdrop, Alpha Centauri AB will also have to travel around the Earth. But then every day Alpha Centauri AB will need to travel its distance from our (presumed) geocentric center of reference, doubled to get the diameter of the circuit it must travel, times pi to get the circumference of the curcuit, times 365 to convert light year speed to a distance traveled in a single 24-hour period, by which we arrive at a speed for Alpha Centauri AB as it travels around the Earth of 10,016 light years per day. That's a little over one million percent of the speed of light, which is a constant in all frames of reference at one millionth the extrapolated speed of Alpha Centauri AB. If that is not a blatant falsification of the Ptolemaic model, it's difficult to think of what would be.
But that is not the end of the embarrassing problems for Hawking/Mlodinow, based on their own statements. Recall the claim that "There is no picture- or model-independent concept of reality." (42) But what about their handling of the question of free will in the face of the admission that their deterministic paradigm may well never be able to provide a model of how human volition works:
"How can one tell if a being has free will? ... We cannot even solve the equations for three or more particles interacting with each other. Since [a being our size has]...about a thousand trillion trillion particles...it would be impossible to solve the equations and predict what [a being our size]... would do. We would therefore have to say [by default] that any complex being has free will--not as a fundamental feature, but as an effective theory, an admission of our inability to do the calculations that would enable us to predict its actions." (178)
So no effective model of human volition is possible, but free will is posited by default as "an effective theory." That sounds like "a model-independent concept of reality." Of course, the hedge that the "theory" is not a "fundamental feature" was made. But there it is for all to see: a "fundamental feature" of reality for which there is no model. That directly contradicts the claim that "There is no picture- or theory-independent concept of reality." That is, unless a "theory" that can't account for what it is a theory of counts... This is a version of the commonplace objections to old-style positivism that things like love, which we know about, can't be observed in the way positivism requires. But it's nice to have THE GRAND DESIGN provide another example for its ideological opponents.
This is enough to show that Hawking and Mlodinow are very much in need of the philosophical perspective they begin their book by disparaging. Since the grand move by which they want to place philosophical theology out of bounds forever more (model-dependent realism) is so deeply flawed, we can safely call that project as questionable in the least, if not outright failed.
A more interesting line of enquery going forward is whether the questions one can ask when going meta on the new quantum-based physics account of consmology are still meaningful. (Hint: See the C. S. Peirce quote at the head of this blog!)
Note: What a friend has called "the occasion gauntlet," aka, "the holidays," is upon us. I'll get to the next post when I can--but I promise, it will be fun. Since the comments are disabled, email me at Tracy.Witham@gmail.com with any questions. Any credible challenge will be noted and responded to.