Physics and Philosophy: Is There a Common Ground?

Physics and Philosophy

In a famous remark touching on the difficulty of grasping physics at the quantum level, the late great physicist and science communicator Richard Feynman wrote, “I think I can safely say that nobody understands quantum mechanics.” [1] I boldly differ with Feynman on this point. Thousands of people, including even some non-physicists, understand at least the basics of quantum mechanics reasonably well (his admirable and characteristic modesty notwithstanding, Feynman himself had a very solid understanding of the subject). However, Feynman’s remark does apply very well to those who write about quantum mechanics in abstract philosophical or metaphysical terms, especially those who have no background or expertise in physics. Like any other area of knowledge, scientific or otherwise, it is important that one really understands the subject before coming up with a complex thesis on it. Many if not most self-described gurus of “quantum spirituality” do not meet this criterion of qualification. Much of the popular literature claiming parallels between New Age belief and quantum mechanics are shining examples of a sort of “intellectual anarchy” that is trendy in today’s culture. As Milton Rothman writes,

Everyday anarchy romps through the current intellectual scene: an engineer [young-earth creationist Henry Morris] writes books on evolution, a science fiction writer becomes a psychotherapy guru and founds a new religion [L. Ron Hubbard, founder of the Scientology pseudoscience], a psychoanalyst rewrites the laws of celestial mechanics [Immanuel Velikovsky of Worlds in Collision infamy], theologians give pronouncements on physics, physicists write books on theology, and legislators write laws defining life. [2]

To this list of prominent examples we can add the spectacle of a physician named Deepak Chopra writing books about and making grand pronouncements on quantum mechanics, despite the fact that he clearly has no understanding of or educational background in quantum mechanics.

The looseness with which quantum mechanics is treated by armchair physicists who have an ideological bone to pick is one of the justified reasons for the prevailing attitude of dislike toward philosophy currently seen among many in the physics community (this is mostly the case with experimental and practical physicists, but is true even of some theoretical physicists as well). This was not always the case; the current aversion to philosophy among the hard physics community started in earnest with the post-World War II physicists. Prior to the war, the great physicists of the twentieth century – among them Bohr, Heisenberg and Schrödinger – were very interested in the philosophical implications of quantum mechanics and of the other kinds of physics they studied. This interest was especially strong in Einstein, who often waxed philosophical in his writings and lectures. This early interest in philosophy among physicists is not (or should not be) inherently surprising or anomalous. As Rothman points out, “modern philosophy of science is to a great extent the philosophy of quantum theory . . . quantum theory, in its role as the fundamental theory of matter and energy, makes a number of statements which contradict our ‘commonsense’ notions of nature. Philosophical problems arise when we try to make scientific sense out of these contradictions.” [3]

Notwithstanding the conduciveness of quantum theory to philosophical “hashing out,” the group that came into prominence in the physics community following World War II (led for the most part by Richard Feynman, Steven Weinberg and other household names) drastically changed the attitudes of most physicists toward philosophy. They emphasized that all we can really know is what we measure and observe, all the rest being nothing but empty and meaningless talk. If we can make accurate measurements and then describe those accurate measurements with theories, it does not matter what the theory really means. Arguing about the underlying “meaning” of theories is a waste of valuable time. The only relevant issue is whether the theory actually works. If it does, then it is “true enough.” If it does not work, it is useless and we toss it out on our way back to the starting board. That is all we really we need to understand, because everything for which we use our scientific theories is based on observed objects and phenomena, not on ontological meaning.

For example, theories are useful for building practical things like electronic circuits. Maxwell’s equations of electricity allow us to create electromagnetic fields emitted by antennae. Do those fields actually exist? As far as the pragmatic physicist is concerned, they can be said to exist only in the sense that they have an observable effect. But no one has ever actually seen an electric field or a magnetic field. All we can see are particles such as electrons being accelerated by the presence of other electrons or other charged particles. That activity is what physicists measure and observe. The description of that measured observation is the theory, in this case a model of fields. If the theory works, then it is good enough and physicists do not lose sleep over questions of whether there is a one-to-one correspondence between theories and ultimate reality. This is why the definitions physicists use in their calculations and data analysis are strictly operational in nature. For example, starting with Einstein in the early twentieth century, scientists have defined time as “what one reads on a clock.” All the other various observational qualities scientists routinely employ follow on the heels of this pragmatic and operational approach: Distance is what you read with a meter stick, a meter being currently defined by international agreement as the distance light traverses between two points in a vacuum during 1/299,792,458 of a second. Temperature is what you read on a thermometer, etc. [4] Metaphysics has no place in this approach. As the late experimental particle physicist Victor Stenger explained, “Describing nature in terms of physical variables is like sketching or photographing an object. Isn’t it rather foolish to equate images on a piece of paper with the real thing? Confusing an image with reality is a common characteristic of small children.” [5]

If empirical observations and experiments are the building blocks of scientific models, then operational definitions are the language in which the instruction manual is written. In his popular 1988 book A Brief History of Time (a book more often purchased and quoted than read and understood), world-renowned physicist Stephen Hawking defines the true value of a theory in terms of such model-building:

I shall take the simple-minded view that a theory is just a model of the universe, or a restricted part of it, and a set of rules that relate quantities in the model to observations that we make. It exists only in our minds and does not have any other reality (whatever that might mean). A theory is a good theory if it satisfies two requirements: It must accurately describe a large class of observations on the basis of a model that contains only a few arbitrary elements, and it must make definite predictions about the results of future observations. [6]

This description and account of scientific theory represents, in my view, a legitimate philosophical approach to determining the truth value of any proposition in science. Creationists who parasitize existing biological knowledge in order to make their denial of evolution sound plausible and New Age gurus who distort quantum mechanics in order to make a scientific-sounding case for their preconceived spiritualistic beliefs have not satisfied any criteria of a good theory. This is because the quantum New Agers’ strained harmonization of science and spirituality and the creationists’ post-hoc rationalization of evolutionary evidence fail to actually explain anything we observe.

Yes, Virginia, There is an Objective Reality Independent of Our Senses

The “job description” of every scientist can be summed up in the single word explain. The central aim of science is to demythologize our often faulty and misleading intuitions about the natural world, and thereby to convert the irrationality of pure, unfiltered discovery into the rationality of evidence-based justification. This is done through careful measurement and observation, a process by which the “laws of physics” are crafted. In other words, the laws of physics are inventions of human observers. More and more philosophers of science are beginning to take the view that, in the words of philosopher David Armstrong, “although there are regularities in the world, there are no laws of nature.” [7]

This position was independently arrived at by Victor Stenger, the particle physicist we quoted above, in his important 2006 book The Comprehensible Cosmos. What we refer to as the “laws of physics” are simply restrictions physicists place upon themselves. However, this does not mean or imply that our descriptions of the universe are arbitrary and that we “create our own reality through observation.” On the contrary, this means that scientists are actually constrained to build their models in such a way that they fit the observed data. Moreover, scientific theories and models must be formulated to be objective. That is, they cannot depend on the subjective point of view of any one observer. Stenger demonstrates mathematically in his book that one can derive most of the physics we know from just one simple assumption, which Stenger calls point-of-view invariance: “The models of physics cannot depend on any particular point of view.” [8]

Stenger did not invent the principle underlying his particular formulation of point-of-view invariance. It was discovered in the early twentieth century by a German mathematician named Emmy Noether, who in 1918 proved a theorem now known as Noether’s Theorem[9] The theorem states that any theory involving space and time, if formulated in such a way that it does not depend on any particular moment in time when the observer starts her clock (meaning the theory holds as good now as it did at any time in past history), then that theory will by definition contain a quantity that is conserved, namely energy. The theorem applies to position in space as well; if a theory does not depend on any special location in space, conservation of linear momentum necessarily follows. Finally, if no direction in space is singled out as special in the theory, conservation of angular momentum will automatically be conserved in the equations.

Practically all of classical physics follows from just these three conservation laws (the only exceptions are gravity and some electrical forces, but these do not require much more information to be accounted for). All our knowledge of classical physics, acquired from Newton to the twentieth century, follow neatly from conservation of energy, conservation of linear momentum and conservation of angular momentum, and these principles follow in turn from point-of-view invariance. The implication of Noether’s discovery is profound. It means that so far as we know there is no external force – spiritual or otherwise – governing the behavior of matter from above. This also means that the “laws” of nature do not necessarily describe ultimate reality.

Again, this does not imply the absence of an underlying objective reality independent of our subjective experience, as the peddlers of New Age mysticism would have us believe. On the contrary, point-of-view invariance and Noether’s Theorem show that there must be an objective reality. As Stenger explains,

[Point-of-view invariance] comes simply from the apparent existence of an objective reality – independent of its detailed structure. Indeed the success of point-of-view invariance can be said to provide evidence for the existence of an objective reality. Our dreams are not point-of-view invariant. If the Universe were all in our heads, our models would not be point-of-view invariant.

Point-of-view invariance is thus the mechanism by which we enforce objectivity. If we did not have an underlying objective reality, then we would not expect to be able to describe observations in a way that is independent of reference frames. [10]

Even though we currently have no way of knowing what the “true” structure of reality looks like, the existence of an objective reality underlying and informing the imperfect but adequate models we use to describe observations is confirmed every moment of every day by numerous obvious (and some not-so-obvious) impositions of what Rothman calls “laws of denial” (which he compares and contrasts with “laws of permission”). “Choosing between the possible and the impossible is a task carried out by means of the laws of denial, which tie us firmly to reality even as imaginations soar unfettered through the universe.” [11] Not everything we may want to happen can happen, the assertions of Rhonda Byrne’s doctrine of “The Secret” to the contrary notwithstanding. We cannot create our own reality, and the universe does not care what we want or desire. We cannot “dance this world away,” in the words of the Rick Springfield song.

Note that Rothman uses the word “choosing” in his statement about distinguishing between the possible and the impossible. While it is true the laws of physics are human inventions, they must agree with the observed data in order to be considered valid. For example, we cannot just “choose” to travel faster than the speed of light, no matter how much we may desire it. The theories and models scientists find useful in making testable predictions that can be verified or falsified are anything but arbitrary. Science is not a branch of postmodernism, the ill-begotten position which asserts that science is simply one cultural narrative among many and that all narratives are equally true. That is simply not the case. There is only one narrow set of “narratives” that work, namely the ones that agree with the data. Philosophy is in principle capable of making important contributions to science, but only when it is divorced completely from metaphysics and recognized for what it is: a method or toolkit for critical thinking rather than a self-contained subject or program unto itself.


NOTES

[1] Richard Feynman, The Character of Physical Law (Cambridge: MIT Press, 1967), p. 129.

[2] Milton A. Rothman, A Physicist’s Guide to Skepticism: Applying Laws of Physics to Faster-Than-Light Travel, Psychic Phenomena, Telepathy, Time Travel, UFO’s, and Other Pseudoscientific Claims (Buffalo, NY: Prometheus Books, 1988), p. 13.

[3] Ibid, p. 71.

[4] Bureau International des Poids et Mesures (BIPM), The International System of Units (SI), 8th ed., 2006.

[5] Victor J. Stenger, Physics and Psychics: The Search for a World beyond the Senses (Buffalo, NY: Prometheus Books, 1990), p. 233.

[6] Stephen W. Hawking, A Brief History of Time: From the Big Bang to Black Holes (New York: Bantam, 1988), p. 9.

[7] D.M. Armstrong, What Is a Law of Nature? (Cambridge: Cambridge University Press, 1983), p. 5.

[8] Victor J. Stenger, The Comprehensible Cosmos: Where Do the Laws of Physics Come From? (Amherst, NY: Prometheus Books, 2006), p. 57.

[9] Nina Byers, “E. Noether’s Discovery of the Deep Connection between Symmetries and Conservation Laws,” Israel Mathematical Conference Proceedings 12 (1999), http://cwp.library.ucla.edu/articles/noether.asg/noether.html (accessed February 13, 2016). This web page contains links to the original paper by Noether, including M.A. Tavel’s English translation.

[10] Stenger, The Comprehensible Cosmos, p. 187.

[11] Rothman, A Physicist’s Guide to Skepticism, p. 137.

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About Nathan Dickey

I am a freelance writer trying to finish my degree in Journalism. I attended Southern Oregon University in Ashland, Oregon. My interests are many, and include investigative reporting, science, philosophy, history, classic rock music, and pop culture analysis. My motivation in writing is to contribute what I can to the promotion of science and skepticism among the public. My goal is to use my journalism training to be active in the skeptical and freethought movement, analyzing dubious but popularly-believed claims involving the supernatural, the paranormal and religion.
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