Quantum Physics: Is Everything Determined? Egnor vs. PapineauPhysicalist philosopher David Papineau is clearly unhappy with the implications of quantum mechanics, as neurosurgeon Michael Egnor sets them out
Yesterday, we published the fifth portion of the debate between materialist philosopher David Papineau and neurosurgeon Michael Egnor, where the key issue was “Can traditional philosophy help us understand the mind vs. the brain?” In this final instalment, we look at the portion which starts roughly at 47 min where Papineau and Egnor start to talk about quantum physics, the physics that governs electrons, which famously do not obey the same rules as larger particles and are also the most basic level of the brain (partial transcript):
Note: Dr. Papineau is a “physicalist.” On that view, “the mind is a purely physical construct, and will eventually be explained entirely by physical theory, as it continues to evolve.” (Philosophy basics) He is considered to be one of the best defenders of naturalism (nature is all there is), often called “materialism.”
David Papineau: I am one of the philosophers of quantum mechanics who appeals to decoherence to understand quantum mechanical processes, and like others who appeal to decoherence, we do not believe in the collapse of the wave function. We think that’s an apparent phenomenon. It’s a superficial, [00:47:30] macroscopic phenomenon, and at the bottom level, there’s no collapses, so …
Note: Decoherence? That’s the collapse of quantum particles like electrons into a single state when they are measured. Erwin Schrödinger’s famous cat is then either alive or dead. In the joke, courtesy Philip Ball in The Atlantic, 2018:
Schrödinger is driving along when he is pulled over by a policeman. The officer looks the car over and asks Schrödinger if he has anything in the boot.
“A cat,” Schrödinger replies.
The policeman opens the boot and yells, “Hey! This cat is dead!”
Schrödinger replies angrily, “Well, he is now.”
(The officer, by the very act of checking, forced the quantum cat to be either alive or dead, rather than in an indefinite state.)
Collapse of the wave function?: Elementary particles in the universe do not, according to the conventional Copenhagen interpretation of quantum physics, have an actual position until they are measured. “But which of those possible states is a particle actually in, pre-measurement? The most popular answer, formulated around the time Schrödinger produced his equation, is known as the Copenhagen interpretation. Named after the home city of one of its pioneers, Niels Bohr, it says that a particle’s state before observation is fundamentally, intrinsically, insurmountably uncertain. If the wave function says a particle could be here and there, then it really is here and there, however hard that is to fathom in terms of everyday experience. Only the act of looking at a quantum object “collapses” its wave function, jolting it from a shadowy netherworld into definite reality.” – New Scientist See also: In quantum physics, reality really is what we choose to observe.
Michael Egnor: Do you endorse the many worlds phenomenon, the many worlds theory?
David Papineau: I prefer the many worlds view, but I was just saying was consistent with …
Michael Egnor: This is fascinating. David, you have just gotten done ridiculing, ridiculing Aristotelian, Thomistic [00:48:00] metaphysics because it involves the concepts of intelligibility and form, but you have accepted the idea that with every quantum event, an entirely new universe is created. If you’re talking magic, if you’re talking crazy stuff, boy, that is the pinnacle. That is the pinnacle. You think a new universe is created with any quantum event?
David Papineau: I don’t think you should argue in this way if you don’t understand the theory. I don’t think an entirely new [00:48:30] universe is created every time there’s a quantum event. I think there’s a local branching. It doesn’t involve the entire universe at all. It doesn’t proceed any faster than the speed of light. It’s a local thing, nothing magical about it at all. I think you’re working with a rather vulgar view of the Everettian understanding of quantum mechanics. But if we’re going to start pouring scorn on [00:49:00] other people’s worldviews, I don’t think we’re going to know where to stop, so perhaps we’d better proceed in a different manner.
Note: Many worlds view of the universe: “The Many-Worlds Interpretation (MWI) of quantum mechanics holds that there are many worlds which exist in parallel at the same space and time as our own. The existence of the other worlds makes it possible to remove randomness and action at a distance from quantum theory and thus from all physics.” …
“The fundamental idea of the MWI, going back to Everett 1957, is that there are myriads of worlds in the Universe in addition to the world we are aware of.” Stanford Encyclopedia of Philosophy Also: Everett, H., 1957, ‘Relative State Formulation of Quantum Mechanics’, Review of Modern Physics, 29: 454–462; see also ‘The Theory of the Universal Wave Function’, in B. De Witt and N. Graham (eds.), The Many-Worlds Interpretation of Quantum Mechanics, Princeton NJ: Princeton University Press, 1973.
A long digression follows in which Dr. Egnor talked about the way epileptic seizures affect the brain in a way that they do not affect the mind. We will look at that on Sunday. They returned to a discussion of quantum physics with the discussion of the work of physicist John Bell (1928–1990)
Michael Egnor: You’ve heard of John Bell’s work, with Bell’s [01:00:00] inequality? A quantum state is not determined by the state before the quantum. Determinism is false. You do know that, that determinism, in physics, has been very conclusively shown to be not true.
David Papineau: I don’t think you should be lecturing me about quantum mechanics.
Michael Egnor: No, you could pull the authority, but do you think determinism is true [01:00:30] in quantum mechanics?
David Papineau: Yes, I do, actually. But so do all Everettians, and so do all Bohmians, and among philosophically inclined physicists and philosophers, the supposed indeterminism of quantum mechanics is very, very dubious. …
Arjuna: [host, noting that they were out of time] So, I think we’re not going to be able to have a whole quantum physics debate here.
Note: John Bell (1928–1990) was an Irish physicist who sought to show that determinism was true. But his famous Bell’s inequalities showed the opposite: “[T]here is a central problem with determinism: It is clear from physics that determinism in nature is not true. In 1964, theoretical physicist John Bell (1928–1990) proposed relatively simple and ingenious experiments to test whether nature determines each event beforehand. The physicists asked, are there “hidden variables”—hypothetical states of nature that exist before unpredictable quantum events that completely determine the outcomes? These experiments have been done—at least seventeen times—and have conclusively shown that there are no local hidden variables that determine outcomes.” – “A materialist gives up on determinism”
You may also wish to read the earlier portions of the debate:
Neurosurgeon Michael Egnor takes on philosopher David Papineau Round 1. In the debate, Egnor begins by offering three fundamental reasons why the mind is not the brain. Neuroscience caused Egnor to honestly doubt Papineau’s materialist perspective that the mind is simply what the brain does.
Round 2: Philosopher Papineau replies to neurosurgeon Egnor. Dr. Papineau is considered to be one of the best defenders of naturalism (nature is all there is), often called “materialism.” Papineau: Mental processes, including conscious processes, are one in the same as physical processes. I’m curious about how Michael Egnor would answer it.
Round 3: Egnor vs Papineau: The Big Bang has no natural beginning. In the debate between theistic neurosurgeon Michael Egnor and naturalist philosopher David Papineau, the question gets round to the origin of the universe itself. Egnor maintains that the Big Bang, which is held to have created the universe, is an effect with no physical cause. Papineau agrees.
Round 4: Egnor vs. Papineau Egnor defends the mind vs. the brain
Round 4: Philosopher David Papineau does not feel that neurosurgeon Michael Egnor is being “entirely helpful” at this point… It became quite the dustup actually. Egnor deals with the brain as an organ, not a theory, and doesn’t see it as equivalent to the mind. Papineau differs.
Round 5: Can traditional philosophy help us understand mind vs. brain? Michael Egnor asks us to look back to the traditional idea that the soul is the “form” of the body. In the Western world, the traditional view of the soul originated with Greek philosophers, chiefly Aristotle and Plato.
Also: Philosopher: Consciousness Is Not a Problem. Dualism Is! He says that consciousness is just “brain processes that feel like something” Physicalist David Papineau argues that consciousness “seems mysterious not because of any hidden essence, but only because we think about it in a special way.” In short, it’s all in our heads. But wait, say others, the hard problem of consciousness is not so easily dismissed.