Friday, August 6, 2010

Objective reality and quantum physics

Hey, for my first post I figured I'd share with you all an excerpt from a wonderful textbook I read about a year ago in a college course I took on philosophy of science. The professor, Dr. Michael Mussachia, wrote this textbook and was quite passionate about philosophy and cognitive science. It was my first exposure to a philosophy professor who had some significant experience in science --Dr. Mussachia worked as particle physicist if I'm not mistaken.

Anyways, the textbook is called "Science: Its Cognitive and Philosophical Foundations"

This section, entitled "12.2 Objective Reality", is section two of Chapter 12: "A naturalistic epistemology. Part 1". This small excerpt does not do the thoughts and ideas of the entire textbook justice (obviously), but it is an illuminating discussion on the popularization of quantum physics.

12. 2 Objective Reality – by Michael Mussachia

A fundamental metaphysical assumption underlying both every day cognition and science is that there is a knowable, objective reality outside our minds. It is objective because its characteristics are not determined, at least for the most part, by human perception, beliefs, and or desires. The big exception to this general rule is our own social world, there indeed the perceptions and beliefs of the observer, when they are expressed in some form of behavior, can influence the observed. Most of the physical things and processes of the world, however, have characteristics that are intrinsic in them rather than dependent upon human or animal cognition. The material composition of a stone, the voltage across an electrical circuit, and the orbital motion of the earth around the sun are not a function of human perception or belief, though some of these things may be influenced by human action.

While this scientific view is also the common sense view among non-scientists in their everyday lives, there are two counter tendencies within the broader culture: “quantum consciousness” New Age devotees who believe that much if not all of the physical world is shaped by our minds, and social constructivists, who claim that reality is in some sense a social construction.

New Age popularizations of quantum physics typically claim that physical reality is subjective because it is “determined by our perceptions.” New Age gurus proclaim that the quantum wave becomes a particle only when we perceive it to be so. To hear many quantum mystics describe it, you would think our minds interact with matter in some mysterious and even mystical way. A typical example is that of Deepak Chopra in his book Quantum Healing (Bantam 1989): “Every time we think, something material – the neuropeptide – springs out of nowhere. There is some hidden transformation that turns a thought into a molecule.” Such notions seriously misrepresent quantum physics and the nature of measurements in physical science.

To observe and measure something at the micro-level requires a physical interaction with it or with something connected to it under conditions of “wave functions entanglement.” An electron is a very tiny thing, and its behavior is significantly perturbed by an interaction with just a single photon. We observe things with light, and even if we need only a few photons to observe the state of an electron, the act of observing it will change its state. This in turn usually has the effect of making the electron’s quantum state more deterministic. Thus the state of the particle is dependent upon our observations ONLY because observations are measurements, and measurements are causally significant interactions.

For instance, observations that result in particle-like behavior in quantum interference experiments require a physical interaction, usually with some kind of physical device located along one of the paths of the particle beams. The physical interaction along one of the paths makes the particle beam paths different, and as a result the particles no longer interfere like waves. The observation has physically altered the observed, but it has not created the observed.

There is another confusion common in New Age quantum mysticism, Observations are often taken as equivalent to consciousness and hence beliefs. As one New Age guru put it, “… what science is saying now, that reality is what we perceive it to be”, and “When the observer is in the lab looking at the subatomic particle and watching it change according to the consciousness of the observer, he’s creating a subatomic particle.” (Cited in Gordon, 1988, page 181-182.) Unfortunately, beliefs without actions can neither cause an electron to jump across a semiconductor junction nor put food in the stomach of a starving person. Electrons may be altered by the photons of our observations, but they couldn’t care less about our beliefs. If they did, we wouldn’t need to carry out laborious and difficult physical experiments; we could make do with just thought experiments.

The ability of our observations and measurements to influence the behavior of things is quite limited. Another way to put it is that quantum indeterminacy has its limits. We cannot make an electron do just anything by observing it. No observation will turn an electron into an anti-electron, or a proton, or neutrino, or a quark, or many other things because the transformations and quantum state shifts are restricted by a variety of physical laws. Similarly, even the holiest of gurus cannot turn an apple into an orange or a stone into a loaf of bread. For better or for worst, the world is largely objective in its characteristics, and if we want to bring about a change, we’ve got to do something more than just desire it, think it or talk about it.