pets endangered by possible book avalanche
1618 times in 1222 posts
Re: Ch. 3 - What is Reality?
What is Reality?
In this chapter, Hawking and Mlodinow introduce tendentious claims.
From the observation that a goldfish sees its world through the prism of its bowl, they conclude that “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.”
This is a tendentious mathematical claim. The earth is part of the solar system, the sun is not part of the terrestrial system. The sun is a local centre and is always within one diameter of the solar system centre of mass. Assuming the earth to be at rest requires either a refined relativistic knowledge of the warping of space-time or the false theory of planetary epicycles. I think their point may be that heliocentric astronomy has to be put in a galactic reference frame, and we have known since Kepler that the sun is not at the centre of the earth's orbit but at one of the elliptical foci. The point is that all finite frames of reference may be encompassed in a bigger frame of reference, but the goldfish bowl analogy is badly made. Heliocentrism is a far more accurate model than geocentrism.
From the philosophical argument that we might live in a matrix controlled by aliens, they then conclude “there is no picture- or theory -independent concept of reality.” In my opinion this line of argument is complete garbage at one level, that we know the universe exists independent of our concepts about it. Here, if I may be permitted a slightly cryptic allusion from Marx, we see history repeat in the eighteenth Brumaire of Rene Descartes. Descartes’ demon who he feared might make all our perception illusory is the first occurrence of this modernist rational tragedy. Hawking’s matrix that might serve the same purpose to diffuse illusion is the history of Descartes' philosophy repeating as farce. And this from writers who say philosophy is dead. They copy the Cartesian formula of doubt.
Model-dependent realism is the current mainstream scientific view, but it is anti-realist. Against realism, they posit that “a particle has neither a definite position nor a definite velocity unless and until those quantities are measured by an observer.” Realism says all particles have position and velocity even if we can’t tell what they are. based on the view that a particle is a thing with mass and energy.
The anti-realism of modern science hinges on the definition of the word ‘definite’ underlined above. Particles have actual position and velocity, but we can’t tell what it is, so these quantities are not ‘definite’. This fetish of the definite leads Hawking to conclude that “theories are no more than useful instruments that do not embody any deeper truths.”
So, the theories of quantum mechanics, gravity and general relativity do not ‘embody any deeper truths’. This is absurd in the face of the verification these theories have found in evidence.
No wonder the authors then proceed to announce their approval of the absurd idealism of Bishop Berkeley, who said to be is to be perceived. The implication might be drawn that nothing exists in nature beyond what we can perceive. Hawking and Mlodinow say the pain in Dr Johnston’s foot when he kicked the stone was just an idea in his mind.
The grey eminence of positivist science, David Hume, is then invoked as the source of the founding principle of anti realism: “we have no grounds for believing in an objective reality but must behave as if it exists."
Does anyone else see tinges of Lewis Carroll in Hume's failure to see ground for believing in an objective reality?
Alice reaches Wonderland when the authors tell us that “model-dependent realism short-circuits all discussion between realist and anti-realist schools of thought.”
Reality, for modern astronomy, becomes a matter of convenience, apparently “solving the meaning of existence” (or at least avoiding it).
A source of idealistic difficulty is in the theory of quarks; many scientists find it “too much” to “assign reality to a particle, that might be in principle unobservable.”
The epistemology here would possibly make sense, except that then the authors say that creationism is “one possible model”. Here their logical sloppiness becomes extreme. Creationism is not “one possible model”, it is an obsolete error. And yet the authors have the hide to say neither big bang theory nor Genesis creationism “is more real than the other”, in some bizarre deference to cultural relativism.
In a respite from channeling Bishop Berkeley, the authors explain models and elegance, observing that from Einstein, “a theory should be as simple as possible, but not simpler.” They say the trouble with modern physics is that the standard model is not entirely elegant.
Overall, I found this chapter disturbing, because the epistemology of model dependent realism suggests we have no access to objective reality. It may seem that way for scientists who define access as precise definition in theory, but we also have everyday access to objective reality through ordinary relations of life and understanding and history. Objective reality can impinge on any theory, even before the theoreticians understand the nature of the reality that enframes their thought.
Last edited by Robert Tulip on Sun Nov 07, 2010 5:53 am, edited 1 time in total.