Rand's Objectivisms' central tenets are that reality exists independently of consciousness, that human beings have direct contact with reality through sense perception, that one can attain objective knowledge from perception through the process of concept formation and inductive logic.
Quantum physical experiment after experiment has shown that if we assume that the particles that make up ordinary objects have an objective, observer-independent existence, we get the wrong answers.
Which is it?
Rand's Objectivisms' central tenets are that reality exists independently of consciousness, that human beings have direct contact with reality through sense perception, that one can attain objective knowledge from perception through the process of concept formation and inductive logic.
Rand didn't say much about induction except that she didn't know how it works from the appendix to "Introduction to Objectivist Epistemology":
Prof. M: The question is: when does one stop? When does one decide that enough confirming evidence exists? Is that in the province of the issue of induction?
AR: Yes. That’s the big question of induction. Which I couldn’t begin to discuss—because (a) I haven’t worked on that subject enough to even begin to formulate it, and (b) it would take an accomplished scientist in a given field to illustrate the whole process in that field.
An idea that Rand freely admits she didn't understand can hardly be regarded as central to Objectivism.
Your write:
Quantum physical experiment after experiment has shown that if we assume that the particles that make up ordinary objects have an objective, observer-independent existence, we get the wrong answers.
This is false. In quantum mechanics, a system in general does not have a single value for each measurable quantity. Rather, the system exists in multiple instances that are partitioned into versions, with each version having some particular measurable value. So there is a version of my coffee mug sitting in its current position on the table next to me, and another version one millimetre away from that, and many other versions of the mug. We can tell that these different versions of a system exist by doing experiments such as interference experiments. See "The Fabric of Reality" by David Deutsch, Chapter 2.
When you measure a system, you evolve so that after the measurement there are multiple versions of you, one for each version of the system you measured. Before the measurement there is no single fact of the matter about what outcome you will see. Some people are confused by this into thinking that the system doesn't exist before you do the measurement or similarly silly ideas. But this is refuted by the fact that you can manipulate the system before measuring it, which you could hardly do if it didn't exist.
Quantum mechanics doesn't refute the existence of an objective world. Rather, it claims that the world is very different from how people imagined it before quantum mechanics.
Does quantum mechanics refute the idea that I have direct contact with reality through sense perception? No. It just says that the reality I have contact with through sense perception is a lot more complex than it appears at first glance.
Nor does quantum mechanics refute the idea that we can understand reality. Arguably it puts in a better position to understand reality, since it allows the construction of computers that can simulate any physical system to any desired degree of accuracy:
http://www.daviddeutsch.org.uk/wp-content/ItFromQubit.pdf.
Some people claim that quantum mechanics is so strange that the laws of logic don't apply to it and that a new quantum logic if needed. In reality, ordinary logic still applies to quantum mechanics, provided you take the propositions as being about the whole of physical reality, i.e. - a description in terms of all of the versions of each system and how the versions interfere with one another.
Bohm believed in an objective reality that had a hidden part which is difficult for us to measure, observe or think about, but not impossible. That made Bohm's thought (although he had been socialist by mistake) very similar to the philosophical views of Ayn Rand.
Let's first address the elephant in the room. Ayn Rand was a philosopher who would not engage in any philosophical debate with claims that ran contrary to her common-sense vision of the world. A theory or a philosophical stance which attempted refuting Rand's claims would typically be ridiculed as "irrational", "bad science", or "bad philosophy". Most Objectivist followers today, who accept Leonard Peikoff as Rand's heir, follow suit in almost all of Rand/Peikoff claims. This includes a vehement (and bizarre) misinterpretation of Kant as a philosopher who was anti-Enlightenment. Because of this particular attitude shown by many Objectivists, they are not engaged with by the academia, not to mention members of scientific community.
With that out of the door, Ayn Rand's account of causality (and free will) is incompatible with modern physics. By Rand's account, each object has an identity and its causal powers. However, since objects are field excitations sustained by various mechanisms of repellment, they do not exist in the solid "object" sense on the particle level. They are also driven by forces, laws and interactions beyond their control, and as such, they cannot possess independent causal powers. And no modern physics theory would posit such causal powers. Not even Bohmian mechanics that was already mentioned here would work as it implies a rather extreme type of determinism which has no place for free will. The view that a stone strives to reach its natural goodness by gravitating towards earth is Aristotlean essentialism:
how does Objectivism reconcile free will with causality? The answer to that question is that Objectivism has an Aristotelian, entity-causation view of causality. Causality is the law of identity applied to actions, and actions are actions of entities. It is entities, i.e., things, that act. A ball rolls, an atom decays, etc.
Thus, Rand has to reject large portions of modern physics and retort to classical mechanics coupled with Aristotleanism to retain her stance. And this is indeed the case.
Objectivists like Leonard Peikoff, David Harriman, and Petr Beckmann reject modern physics deeming it Kantian, therefore "bad", and wish us to go back to Newtonian physics where time is absolute (See: The Philosophic Corruption of Physics). Naturally, they have to reject quantum mechanics for its probabilistic nature and underlying mathematic abstraction along with Einstein's theory of relativity, for similar reasons.
Historically speaking, in the 80s, Objectivist Petr Beckmann, an associate of Ayn Rand, led an anti-Einsteinian physics journal Galilean Electrodynamics. Beckmann also wrote a book Einstein plus Two that aimed to "debunk" Einstein's relativity. More modern Objectivist publications of Harriman and Peikoff also attempt put quantum mechanics and Einstein's theory into question.
Thankfully, those are investigated by Warren C. Gibson as a part of the Ayn Rand Studies series. Gibson engages with those in Modern Physics versus Objectivism paper2. From the Abstract:
Leonard Peikoff and David Harriman have denounced modern physics as incompatible with Objectivist metaphysics and epistemology. Physics, they say, must return to a Newtonian viewpoint; much of relativity theory must go, along with essentially all of quantum mechanics, string theory, and modern cosmology. In their insistence on justifications in terms of “physical nature,” they cling to a macroscopic worldview that doesn’t work in the high-velocity arena of relativity or the subatomic level of quantum mechanics. It is suggested that the concept of identity be widened to accommodate the probabilistic nature of quantum phenomena.
Warren C. Gibson, having substantial knowledge in the field of physics, engages and quotes numerous passages from various books produced by two prominent Objectivists. In the paper itself, there are a plethora of remarks (along with equations) against the Objectivist stance on modern physics. Hence, I am only going to bring in some excerpts. For a longer read and the argument, I encourage getting and reading the paper itself.
To summarize the point, briefly, Gibson states:
In each area, we find similar complaints from P&H [Peikoff & Harriman]: (1) physicists fail to provide “physical explanations” for their theories; (2) they are on the wrong track because they fail to follow Rand’s epistemological prescriptions; and (3) although it is generally not stated, they imply that physicists should mend their ways and get with the Peikoff-Harriman-Newtonian program
Generally, both Peikoff and Harriman deem that modern physics makes the external world "noumenal" (i.e. "Kantian/Evil"), leading to a form of "mysticism". Take quantum uncertainty, for that matter. Quantum uncertainty drives Objectivists "crazy". Thus, they reject the probabilistic nature of, and the existence of wave function itself. Gibson:
we see them insisting that nature must conform to their macroscopic visions of how the world ought to be—essentially, what Ayn Rand could have seen or visualized in her living room. But if they wanted to preserve the concept of identity, philosophers could simply recognize that probability is part of the nature of a radioactive atom— part of its identity. Then the laws of identity and causality would be preserved.
Today, we understand that entities such as point particles are merely mathematical abstractions and lack spatiality. Yet, we see Peikoff and Handimann rejecting such notions as "fantastic":
For Newton, mathematical equations are valid because they describe physical facts learned from observation. For Einstein, mathematical equations are valid because they belong to a certain self-contained, a priori system of numbers (Peikoff)
They disapprove of any mathematical-physical abstractions that “cannot be interpreted physically”(Peikoff). Futhermore, Peikoff states that:
The physical world, in this new approach, is not a primary, but a derivative of a non-physical realm consisting of pure mathematics. (Peikoff)
So, for Peikoff, it is wrong if “concepts are logically prior to percepts”(Peikoff) because then we operate in the realm of "fantastic premises".
It does indeed resemble a caricature view of Mach's positivism, a little. Gibson concludes:
We have seen P&H repeatedly calling for physical explanations of scientific theories. They seem to be insisting on explanations that conform to Objectivist ontology, and if the findings of physics fail to conform to their demands, then those findings must be tossed. They demand that physics return to the worldview of Newton, where objects interact with other objects strictly according to the nature of those objects. An apt metaphor would be billiard balls colliding on a billiard table. P&H want a world where particles have definite attributes that determine their behavior. They want a world where the “nature” of objects can be determined in isolation from their environments and from the observers that comprehend them.
Thus, the remedy would involve:
[C]oncepts like object, nature, and cause as they appear in Objectivism need to be expanded or revised. Perhaps the concept of the “nature” of an object can be extended to include probability as in quantum mechanics. Perhaps causality needs amendment or extension. Perhaps the uncertainty principle can be reconciled with causality. Objectivists need to confront the aforementioned conflict between Newtonian determinism, where P&H would take us, and free will. They need to ask themselves whether they are clinging stubbornly to macroscopic visualizations that must be abandoned if microscopic phenomena are to be comprehended.
As it currently stands, no wonder that no physicist would engage in such "debate" with Objectivists, especially that any such debate has been notoriously impossible due to the character of Rand's philosophical heir - L. Peikoff.
Note also that Warren C. Gibson's study was published within means that don't belong to Ayn Rand Institute. The Journal of Ayn Rand Studies like The Atlas Society are not organizations affiliated with The Ayn Rand Institute. Those organizations distance themselves from Ayn Rand Institute for its dogmatism and lack of open mindness. So, it might not be the case that all Objectivists share the claims made by L. Peikoff.
One can believe in what Ayn Rand says and not have an issue with QM. Reality can exist out there, independent of us and all the things she believed in. The key is to realise we organise our sense data from that world using models we subconsciously and consciously construct. Now QM is a model basically about observations. Ayn Rand believed the world existed independently of observations. A philosophy compatible with that view (and others as well) is Model Dependant Realty as advocated by Hawking:
https://en.wikipedia.org/wiki/Model-dependent_realism
Ayn Rand is unlikely to accept all of that philosophy (I do not for example), but it can easily be made compatible with her view, as it is with mine.
The key point is to realise that QM is silent about what is going on when not observed (remember, observation in QM is more general than someone looking at things - it is an interaction with a classical apparatus - not realising that gets many into 'trouble'). You can clearly see this by reading the first 2 chapters of Ballentine - QM - A Modern Development and looking into Gleason's Theorem. All Ayn Rand is asserting is reality exists independent of observation even though QM says nothing one way or the other about it.
As an aside, many of the 'issues' in QM are simply a continuation of debates about issues in probability: https://math.ucr.edu/home/baez/bayes.html
I think, for example, Ayn Rand would be attracted to the transactional interpretation.
Thanks Bill
An important distinction which must be made here is that the strange behavior dictated by the rules of quantum mechanics gets averaged away as the scale length that characterizes the system in question is increased. In fact, all quantum mechanical descriptions of systems are required to reduce to classical descriptions as the objects in those systems are increased in size.
This means quantum mechanical descriptions of things like baseballs and brains are indistinguishable from classical descriptions of the same things. And this means that Rand Objectivism has absolutely nothing to do with QM, and vice versa.
"reality exists independently of consciousness"
There might be a slight confusion on this point. Ayn Rand promoted what she called "The Primacy of Existence"... a hierarchical framework that casts existence as the prerequisite for consciousness. This was meant to specifically point out that consciousness cannot in any way exist "independent" from reality (existence) because "consciousness is the faculty of perceiving that which exists." What she meant by "reality exists independently of consciousness" is that your mind doesn't need to perceive existence in order for existence to exist (i.e., consciousness is not a prerequisite for existence). Consciousnesses doesn't need to perceive accurately in order for the law of identity to contradict an inaccurate perception (i.e., mirages etc...). It may feel like this is splitting hairs but her language is very precise specifically so that this conception doesn't get inverted. She wrote extensively about the difference and why it matters.
"human beings have direct contact with reality through sense perception"
It is "direct contact" in the sense that your sensory organs (limited as they are) are the part of you that "touches" reality, but there is a clarifying passage below so as not to oversimplify.
"[Man’s] senses do not provide him with automatic knowledge in separate snatches independent of context, but only with the material of knowledge, which his mind must learn to integrate. . . . His senses cannot deceive him, . . . physical objects cannot act without causes, . . . his organs of perception are physical and have no volition, no power to invent or to distort . . . the evidence they give him is an absolute, but his mind must learn to understand it, his mind must discover the nature, the causes, the full context of his sensory material, his mind must identify the things that he perceives." (“Cognition and Measurement,” Introduction to Objectivist Epistemology, 5)
"one can attain objective knowledge from perception through the process of concept formation and inductive logic."
The passage I referenced above is especially important to the question because it is this "full context of sensory material" including all of the math, concepts, and theory that goes into accurate quantum predictions that crosses the finish line of non-contradiction here. The "nature, the causes, the full context of his sensory material" would have integrated in them the results of these experiments.
"“Knowledge” is . . . a mental grasp of a fact(s) of reality, reached either by perceptual observation or by a process of reason based on perceptual observation."
So knowledge in Objectivism must include the "full context of sensory material."
"Reason is the faculty that identifies and integrates the material provided by man’s senses."
So the oversimplification doesn't really work because you have misunderstood some very important central concepts in Objectivism about sense perception and knowledge. An Objectivist theoretical physicist would not stare at a double-slit demanding that the universe conform to the concepts in contradiction with his senses.
Finally as a comment to @bodhihammer's well written critique I want to point out that he is quite right that not all Objectivists agree with Peikoff on this, and that Peikoff is not a physicist (full disclosure, neither am I). In the courses I have taken I know that physicists acknowledge that there are different rules at play at different scales... when looking at the micro (Quantum Mechanics), "middle world" (Traditional physics or Newtonian), and the macro (Einstein's Relativity).
Ayn Rand herself referred to Objectivism informally as, "a philosophy for living on earth" so ideas about gravitation bending light around a planet or the fluttering of particles in and out of existence was definitely not on her mind. However, I still wouldn't place Relativity and Quantum Mechanics outside the reach of Objectivism's understanding or assert that they diminish its axiomatic concepts of existence, consciousness, and identity at all.
In Ayn Rand's "An Introduction to Objectivist Epistemology" she explains that context plays a crucial role when trying to understand the identity of something for the purpose of definition but that definitions do not exclude those non-essential characteristics from an entity's identity. A baseball, in comprehending it as a baseball, does not preclude its micro characteristics or composition and structure at the micro level (whatever that structure may be)... it also wouldn't include its exact mass and how influenced it is by the mass of the earth. Forming a concept of gravitation or the concept of a particle is separate from forming the concept of a baseball, and I don't believe the law of identity is violated simply when we attempt to "look inside the baseball" or hurl it around a planet at light speed.
I would argue that this should allow Objectivism to accept that different "essential characteristics" exist when the context changes from "middle world" to the micro or macro. The process of concept formation and definition as laid out in Objectivism does not preclude measuring the very small or the very large (or their behaviors). I think what Peikoff seems to be trying to do is demand that we measure particles and planets in inches... which just speaks to his lack of expertise (i.e., not a physicist). I'll have to read some more and try to figure out why he has decided to go that route, but it seems obviously wrong-headed to me.
