Archive for February, 2011

Universal Appeal

23 February 2011

Vortex of a Vacuum

Confessions of an Open Realist
Like a slow-moving detective novel various suspects of an epistemological and ontological inclination have been eliminated chapter by chapter.

Bernard d’Espagnat, writing in chapter six of his On Physics and Philosophy, starts honing in on his favoured if still rather vague suspect, which he’s identified as “open realism” in previous chapters.

In the first chapter he defined the position as a “starting point” for further investigation. It was compatible with any approach save for “radical idealism.”

There is “something” out there that’s independent of the mind, he says, but whether that’s God, the Platonic Ideas, or something else, he’s not letting on.

So here’s a summary of chapter six, entitled “Universal Laws and the ‘Reality’ Question.”

Theoretical Frameworks vs Ordinary Theories
D’Espagnat believes pure physics has two kinds of theories: “theoretical frameworks” and “theories in the ordinary sense of the term.”

Newtonian Mechanics vs Law of Forces
Newtonian Mechanics was believed to have universal applicability. It could accommodate new forces such as electricity and magnetism. Hence it was a “universal theoretical framework.”

Newton’s theory of universal gravitation precisely specified various laws of forces. It concerned itself about details of a specific domain, and hence is a “theory in the ordinary sense of the term.”

Complete vs Partial Universality
What about modern physics? D’Espagnat asks if there are genuine theoretical frameworks out there, a set of laws with complete universality.

Classical Physics vs Modern Physics
Classical physics looked like the foundation of all sciences. Unfortunately it made some wrong predictions.

Quantum mechanics yields correct predictions whenever it’s used, so it’s the only candidate for a universal theoretical framework. Its specific applications such as non-relativistic quantum physics and quantum electrodynamics are ordinary theories.

Hard Sciences vs Soft Sciences
D’Espagnat notes that some thinkers in the soft sciences rightly point out the horrors that result when universality is applied to political and social realms. The difficulty arises when philosophers extend that criticism to the hard sciences.

Evidence vs Convenience
In the soft sciences objections to universality comes down to how useful or not, and how convenient or not the concept of universality turns out to be. This isn’t a logical argument that can be applied to the hard sciences.

Karate Blows vs Disc Galaxies
However, Scientific American runs articles on karate blows and disc galaxies. Can science really be so universal that it can apply to such a diverse range of topics?

Extreme vs Moderate Universalism
The objection isn’t convincing. We can imagine the electric field of an atom guaranteeing the stability of atoms in muscles and in galaxies.

Strictly speaking, says D’Espagnat, we can’t even discount extreme universalism in which everything is predicted from various general laws.

A less ambitious version of universalism (such as Hans Primas’s) says one could choose which laws to use from a larger set depending on the problem at hand.

Naive Realists vs Universalists
Even “naive realists” don’t always accept universality. The “vitalists” felt special rules applied to living beings.

Realists about Theories vs Realists about Entities
Realists about theories generally support universalism, otherwise what would the theories apply to?

Realists about entities (when not realists about theories too) move away from universalism. Despite the evidence of modern physics they feel an individual object has properties possessing an “existential primacy.”

Movable vs Unmovable Real
Even if we can’t move a ghost, flying saucer, or quasar, we can move a rock or an electron beam. Aren’t they real? Well, quantum field theory says a particle is not a reality in itself.

Real Individuality vs Correct Predictions
If you assume an electron is really an individual entity then you’ll predicts results different from modern physics. Remember that quantum predictions have never been contradicted by the evidence.

The Broken vs Unbroken Stick
On a macroscopic scale imagine a stick that’s partly immersed in water. It looks bent. We can move the stick up and down, and therefore move the “break.” That doesn’t make it real.

The Broken Stick vs The Atomic Microscope
Not only can we move a supposedly broken stick we can also move atoms with a tunnel-effect microscope, but that doesn’t prove the atoms exist as localized individual objects.

Objectivist Realism vs Logical Positivism
D’Espagnat tries to steer a course halfway between objectivist realism and logical positivism.

Existence vs Measurement Statements
Different ways of thinking produce different kinds of questions. “Is the stick broken or not?” is asking for a statement about what is “really” happening rather than the results of an observation.

Appearances vs Reality
Philosophers, especially the popularizers, like to point out physical appearances can be deceiving. That table is mostly empty space, for instance, not something classical physics would admit.

Facts in Old vs New Physics
Many thinkers stress the importance of facts. In “old-time physics” the microscopic level was real and precisely defined, serving as the foundation for the macroscopic. Many say that in modern physics there are no real facts as such.

No Boundary vs Fuzzy Boundary
In classical physics there’s no boundary between microscopic and macroscopic. In the new physics there’s a boundary that is rather fuzzy and depends on our observational abilities. The boundary is therefore “weakly objective.”

Classical Microcosm vs Broglie-Bohm
Classical physics saw the microcosm ontologically. A minority view in modern physics, the Broglie-Bohm interpretation of quantum mechanics attempts a microcosmic ontology but runs into difficulties.

Near Realism vs Collective Experience
Near realism (see chapter one) thinks we can ask questions about “reality-per-se.” It’s similar to “realism about entities” and doesn’t fit with the experimental data.

Another approach says our discursive knowledge springs from a “synthetic ordering” of our collective human experience. It’s a form of positivism.

Partial vs Total Positivism
But we don’t have to be total positivists. The Vienna Circle of early twentieth-century positivists confined scientific statements to observations. We’re not logically obligated to agree with this position.

Positivists vs Working Physicists
Most working physicists are intuitively realists. Unlike positivists, physicists changed their mind about total realism because of observational data.

Near Realism vs Objectivist Language
If we stop believing realism about entities (hence reality-per-se) then we can use objectivist language and Carnap’s linguistic framework to ask questions about existence or attributes.

We answer those questions through empirical investigations. We check the stick in the water and we (usually) answer that it’s not broken.

Human Skill vs Robot Fingers
A robot with less skillful appendages might only be able to move the stick up and down rather than carefully checking it from top to bottom.

Carnap would say we’re right to say the stick isn’t broken, and the robot is right to say the stick is broken. Different abilities let us assert different things.

Realism about Entities vs Realism about Theories
If we discard realism about entities we can still embrace realism about theories, which is much more universal than realism about entities.

Pythagorism vs Einsteinism
“Pythagorism” reminds us of how much modern physics looks for symmetry and symmetry-breaking. Espagnat’s term “Einsteinism” is the variant of physicists who miss Cartesian mechanism and search for the “true” concepts supposedly contained in mathematics.

Einsteinism vs Positivism
Einsteinism doesn’t restrict itself to observations of pointers and gradated scales. It’s close to an Ontology (big “O”). Einstein later in life felt general relativity offered genuine descriptions of structures really out there.

Bundled Realism vs Individual Concepts
But Einstein also refused to point to this or that concept as indispensably real. One had to verify the whole array of concepts taken together: physical reality, the outside reality, and the real state of a system, for instance. The verification step would show which concepts were needed and which weren’t.

Pre-arranged Ontology vs Consistency Quest
This “Pythagorean” ontology isn’t set up in advance but results from a successful consistency quest. Einstein believed he’d largely completed that quest, so felt confident in his realist stance.

Kant vs Einsteinism
Einsteinism’s Ontology/ontology (see chapter five) relies on contemporary physics’ mathematical entities. Kant would have disliked the ones that don’t correspond to an “a priori mode of our sensibility.”

This approach gives Einsteinism an advantage over moderate or radical idealism (see chapter 13).

Physics vs Einsteinism
The big challenge to Einsteinism isn’t philosophical but rather the results of modern physics.

In chapter two we saw how the ontological pictures of Feynman formalism made up just a pseudo-ontology.

In chapter three we saw how instrumentalism reconciled relativity and faster-than-light influences (in a realist interpretation).

In chapters four and five we ran into difficulties trying to fit quantum mechanics’ mathematical symbols into an ontological framework.

Platonist Intuition vs Quantum Data
Some physicists still embrace the intuition of pure mathematical beings waiting to be discovered in a world more real than our own.

The intuition is shattered by the experimental data showing the quantum framework’s mathematical formalism can’t access a mind-independent reality.

All “theories in the usual sense” based on this framework, such as supersymmetry and superstring theories, will encounter the same problem.

Independent Reality vs Research Guide
D’Espagnat believes that Pythagorism’s search for symmetry is still the best approach for physicists to take in their research even though mathematical physics can’t truly describe an independent reality.

However, great mathematical laws may still reflect “something” of this reality.

Naive Realism vs Modern Macrorealism
Physicists know that most people’s spontaneous realism is unjustified. Even Broglie-Bohm theory adopts a different kind of realism. But some thinkers want to rescue realism at least in the macroscopic realm.

Realism of the entities and classical mechanics are both correct, they’ll say, on larger scales. On the smaller scale there are two approaches.

Microscopic Measurements vs Partial Logics
Some advocates of macrorealism will say quantum physics describes measurements of the microscopic world but doesn’t describe it “as it is.” Everything we know about the world comes from our senses, but these “empiricists” don’t question the intrinsic reality of this observed world.

Other advocates assume we know the world (more or less) at it really is, but introduce different kinds of logic. Omnés’s “partial logics” are even quantitative. All this is instructive but not a “realist” position strictly speaking.

Quantum Rules vs Universal Frameworks
When it comes to a universal theoretical framework the quantum framework is the only plausible candidate. It has great predictive powers, but is it universal?

Atomicity vs Nonlocality
The “atomicity argument” says quantum mechanics successfully describes particles and fields, atoms are composed of particles and fields, and everything else is composed of atoms. Therefore quantum mechanics must be universal.

But this argument depends on the Cartesian principle of divisibility by thought. It imagines a mind-independent external reality with interacting but distinct parts. Quantum nonlocality (more specifically, nonseparability) disproves this approach in principle.

Atomicity vs Quantum Predictions
We could try to fashion together a compromise: pretend atomicity works, but when it doesn’t then use quantum mechanics for the rest of the predictions. This empirical argument doesn’t help show the quantum framework is universal.

Atomicity vs Born Rule
Another problem with the atomicity argument is that the Born rule says “orthodox” quantum mechanics makes predictions about observations. It doesn’t say whether an event takes place. That makes quantum mechanics “weakly objective.”

Atomicity vs Instrumentalism
Instrumentalism reconciles Aspect-like experiments and relativity theory (see chapter three), so again basic physics seems to be a source of mainly observational predictions.

Macroscopic vs Quantum Physics
The atomicity argument’s internal inconsistency suggests a different approach. With quantum mechanics’ predictive powers so impressive, can we derive macroscopic physics from the quantum framework?

In chapter eight we see recent evidence that it can. Universality of the quantum framework seems established.

Quantum Rules vs Quantum Theories
This quantum universality recalls Newtonian mechanics’ three great laws, which were considered to possess a universal scope. In our arguments we’re concentrating on fundamental questions about the quantum framework, which consist of the rules of quantum prediction.

We’re not really concerned about the specific ways this framework is applied to “theories in the usual sense” such as quantum field theory.

Dummetian Realists vs Antirealists
M. Dummet says realists and anti-realists differ in how they evaluate certain kinds of statements such as class L of general laws and class F of contingent facts (which is what most concerns d’Espagnat).

Knowledge-Independent vs Knowledge-Dependent Truths
Realists will believe a statement has an objective truth value whether or not we have a way to confirm it. Anti-realists believe a statement can be true only if it concerns something we could possibly know.

Imagine the late Mr. X. He led a sheltered life and never had to show cowardice or courage. How do we react to a statement, “Mr. X was a brave man”? A “Dumettian realist” will say it’s a meaningful statement, while a “Dumettian antirealist” will say it’s not.

Obvious Statements vs Complicated Concepts
A problem with Dumett’s approach is it assumes parts of statements are obvious so disputes concern whole statements. In modern physics the mathematical formalism and observational data mean we have to more carefully define “realism” and “antirealism.”

Small vs Large Domains of Definition
“Operational definitions” are discussed in chapter seven, but briefly philosophers debate how far a word’s meaning can be extended. A “consequent antirealist” says a concept depends on the factual data it was designed to describe. D’Espagnat mostly agrees.

However, d’Espagnat notes there may be exceptions. The English empiricists said, “Nothing is in the mind that has not passed through the senses,” but we can’t prove this rule is universal.

Antirealism vs Necessary Ideas
D’Espagnat believes the notion of existence is a “necessary idea” despite the English empiricists (see chapter five). He says one can believe in a necessary idea and still be a kind of antirealist.

Antirealism vs Metaphysical Realism
Citing Lena Soler, he says an antirealist can accept or reject metaphysical realism as long as he doesn’t claim a correspondence between theory and referent.

Constraints vs Correspondences
An “extra-linguistic referent” may still constrain scientific theories, perhaps by indicating that some possibilities won’t work out, even though we can’t describe it directly.

Open Realism vs Metaphysical Realism
D’Espagnat supports “open realism,” which he says is very close to metaphysical realism in a broad sense.

Open Realism vs Soler’s Antirealism
He concludes by saying his views are also compatible with antirealism in the way Soler presents it.