A Quantum world, not a Cartesian world
A Cartesian world view is wrong. A Manichean world view is also wrong.
Unfortunately, as a non-Cartesian, I don’t really believe in Absolute right and wrong, so it’s more accurate to say that A Cartesian World View is impartial and incomplete, with no allowance for the implications of a quantum world.
If quantum theory is “correct” (we don’t allow or use that word) the the Cartesian universe is “false” (ditto).
A quantum world is not understandable, only explainable.
See below why
Feynman on education:
“But then, "The power of instruction is seldom of much efficacy except in those happy dispositions where it is almost superfluous.” (Gibbon)”
I think, however, that there isn’t any solution to this problem of education other than to realize that the best teaching can be done only when there is a direct individual relationship between a student and a good teacher—a situation in which the student discusses the ideas, thinks about the things, and talks about the things. It’s impossible to learn very much by simply sitting in a lecture, or even by simply doing problems that are assigned. But in our modern times we have so many students to teach that we have to try to find some substitute for the ideal. Perhaps my lectures can make some contribution. Perhaps in some small place where there are individual teachers and students, they may get some inspiration or some ideas from the lectures. Perhaps they will have fun thinking them through—or going on to develop some of the ideas further.
Richard P. Feynman
June, 1963
https://www.feynmanlectures.caltech.edu/III_91.html
Feynman on quantum mechanics
https://www.feynmanlectures.caltech.edu/
“1–1Atomic mechanics
“Quantum mechanics” is the description of the behavior of matter and light in all its details and, in particular, of the happenings on an atomic scale. Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen.
Newton thought that light was made up of particles, but then it was discovered that it behaves like a wave. Later, however (in the beginning of the twentieth century), it was found that light did indeed sometimes behave like a particle. Historically, the electron, for example, was thought to behave like a particle, and then it was found that in many respects it behaved like a wave. So it really behaves like neither. Now we have given up. We say: “It is like neither.”
There is one lucky break, however—electrons behave just like light. The quantum behavior of atomic objects (electrons, protons, neutrons, photons, and so on) is the same for all, they are all “particle waves,” or whatever you want to call them. So what we learn about the properties of electrons (which we shall use for our examples) will apply also to all “particles,” including photons of light.
The gradual accumulation of information about atomic and small-scale behavior during the first quarter of the 20th century, which gave some indications about how small things do behave, produced an increasing confusion which was finally resolved in 1926 and 1927 by Schrödinger, Heisenberg, and Born. They finally obtained a consistent description of the behavior of matter on a small scale. We take up the main features of that description in this chapter.
Because atomic behavior is so unlike ordinary experience, it is very difficult to get used to, and it appears peculiar and mysterious to everyone—both to the novice and to the experienced physicist. Even the experts do not understand it the way they would like to, and it is perfectly reasonable that they should not, because all of direct, human experience and of human intuition applies to large objects. We know how large objects will act, but things on a small scale just do not act that way. So we have to learn about them in a sort of abstract or imaginative fashion and not by connection with our direct experience.
In this chapter we shall tackle immediately the basic element of the mysterious behavior in its most strange form. We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery. We cannot make the mystery go away by “explaining” how it works. We will just tell you how it works. In telling you how it works we will have told you about the basic peculiarities of all quantum mechanics.
https://www.feynmanlectures.caltech.edu/III_01.html
**
So we all agree that we don’t live in a Cartesian world but then we approach almost every problem as though we are still living in a Cartesian world.
eg Sciences Po
It is not enough to point out the chapter and verse, you are the leader, it is your job to apply the rules with the judgement of Solomon (and Socrates). No-one said the job was easy.
“In two slit interference, quantum mechanics cannot determine which slit the electron went through.”
This statement reflects not the poverty of quantum mechanics, but its richness.
In classical mechanics, an electron must have a position — it must pass through one slit or the other.
In quantum mechanics an electron might have a position, but there is an infinitely rich variety of other possibilities as well.
It is no failure of our instruments that they cannot measure what does not exist.
The English language was invented by people who didn’t understand quantum mechanics, so it is unsurprising that the language lacks a concise, accurate description of many quantal phenomena.
The strangeness of quantum mechanics carries us to the brink of implausibility — but not beyond.
- Dan Styer, http://www.oberlin.edu/physics/dstyer/TeachQM/
from https://physicscourses.colorado.edu/phys3220/phys3220_fa08/quotes.html
**
a lovely typo correction here
Dec 7: A typo in HW 13 has been corrected: the upper limit on the sum over l in equation 2 should be n-1, not infinity. (Of course, the states with l > n-1 don't exist anyway!)
from https://physicscourses.colorado.edu/phys3220/phys3220_fa08/
**
Quantum physics poems from https://physicscourses.colorado.edu/phys3220/phys3220_fa08/quotes.html
And below are two student poems, from a sweet little book called "Dear Professor, Do you Live in a Vacuum" a collection based on emails sent to a physics professor and compiled by his wife.
You asked if I listened in class today.
And I am writing you now
to show you that I did listen.
You said that if the uncertainy of one is zero,
then the uncertainy of the other is infinite.
It's just that you're one,
and I'm the other one.In describing a photon,
you said that a photon is not a wave,
and it's not not a wave.
And I'm saying that I'm not with you,
and I'm not not with you.
from here https://physicscourses.colorado.edu/phys3220/phys3220_fa08/quotes.html
* Everything we call real is made of things that cannot be regarded as real. Niels Bohr.
* Those who are not shocked when they first come across quantum theory cannot possibly have understood it. Niels Bohr.
* If you are not completely confused by quantum mechanics, you do not understand it. John Wheeler.
* If [quantum theory] is correct, it signifies the end of physics as a science. Albert Einstein.
* I do not like [quantum mechanics], and I am sorry I ever had anything to do with it. Erwin Schrödinger.
* Quantum mechanics makes absolutely no sense. Roger Penrose.
* It is safe to say that nobody understands quantum mechanics. Richard Feynman.
And, in a little more detail, from Richard Feynman:
I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, ‘but how can it be like that?’ because you will get ‘down the drain,’ into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.
Richard Feynman - The Character of Physical Law (Lecture 6)
chat gpt on Cartesian and quantum
is the world still viewed as Cartesian or have we all moved on?
ChatGPT a dit :
The world is no longer universally viewed through a Cartesian lens, though Cartesian dualism—the view that reality is divided into the mental (mind) and the physical (body)—still exerts a significant influence in certain domains, especially in philosophy, science, and cultural assumptions about reality.
Here’s an overview of where we stand:
1. In Philosophy
Contemporary Reactions Against Cartesianism: Many modern and postmodern philosophical traditions have moved beyond Descartes' dualism. For example:
Phenomenology (e.g., Husserl, Heidegger): Emphasizes lived experience and the inseparability of consciousness from the world, challenging the sharp mind-body distinction.
Embodied Cognition: Modern approaches in cognitive science and philosophy of mind stress that the mind is not separate from the body but arises from its interaction with the physical world.
Process Philosophy (e.g., Whitehead): Rejects static dualisms, viewing reality as interconnected and dynamic.
Persistence of Cartesian Dualism: Dualist thinking persists in some analytic philosophical traditions and popular culture, especially in discussions about consciousness, artificial intelligence, and the "mind-body problem."
2. In Science
Cartesian Mechanistic View in Physics and Biology: The Cartesian view of the world as a mechanistic system of separate parts influenced classical physics and continues to influence certain reductionist approaches in biology and neuroscience.
Shift Toward Holism: Many scientists now favor holistic, relational approaches:
Quantum mechanics has shown that the observer and the observed cannot be entirely separated, undermining Cartesian distinctions.
Systems biology and ecology view organisms and environments as deeply interconnected.
3. In Culture
Cartesian dualism underpins much of Western cultural thought, particularly in the separation of mind and body, subject and object, and reason and emotion. However, many movements challenge this:
Wellness and Holistic Health: Increasing interest in practices like yoga, meditation, and integrative medicine reflects a desire to bridge the gap between mind and body.
Postmodern Critiques: Postmodernism questions binary thinking (a hallmark of Cartesianism) in favor of complexity and multiplicity.
4. Technology and AI
Cartesian thinking influences the development of artificial intelligence, where "mind" (as computation or consciousness) is often treated separately from "body" (the physical machine). However, embodied AI research seeks to challenge this Cartesian model.
Conclusion
While Cartesian thinking has shaped much of Western thought and continues to inform certain areas, there has been a significant movement away from strict dualism. Interdisciplinary approaches that emphasize interconnectedness, embodiment, and relationality dominate contemporary discussions in philosophy, science, and culture. Yet, echoes of Cartesianism remain influential, particularly in areas where clarity and distinctions are prioritized.
Vous avez dit :
Which aspects of quantum theory contradict Cartesian thinking?
ChatGPT a dit :
Quantum theory challenges Cartesian thinking in several fundamental ways, particularly the dualistic separation of mind and matter, and the mechanistic view of the universe as composed of distinct, independent entities. Here are the main points of contrast:
1. The Observer and the Observed
Cartesian View: Descartes maintained a strict separation between the observer (mind) and the observed (external reality). The observer was seen as a detached entity capable of objectively studying the world without influencing it.
Quantum Perspective: In quantum mechanics, the observer and the observed are fundamentally interconnected.
Wave-Particle Duality: Whether a quantum entity behaves as a particle or a wave depends on the observer's choice of measurement.
The Measurement Problem: The act of measurement collapses a quantum system's wavefunction, meaning the observer plays an active role in shaping reality.
This challenges the Cartesian notion of objective, independent observation and suggests that the mind and matter are deeply entangled.
2. Non-Locality and Entanglement
Cartesian View: Reality consists of discrete, independent objects that interact locally (through direct contact or proximity).
Quantum Perspective: Quantum entanglement shows that particles can become correlated in ways that are independent of spatial separation, such that the state of one particle instantly influences the state of another, even across vast distances (as demonstrated by the violation of Bell's inequalities).
This undermines the Cartesian assumption of separateness and locality, suggesting a deeply interconnected universe where parts cannot be fully understood in isolation.
3. Indeterminacy and Probabilistic Nature
Cartesian View: Classical mechanics (inspired by Cartesian thinking) assumes a deterministic universe where future states of a system can be predicted precisely if initial conditions are known.
Quantum Perspective: Quantum mechanics introduces inherent indeterminacy:
Heisenberg's Uncertainty Principle: It is impossible to precisely determine both the position and momentum of a particle simultaneously.
Wavefunction Probabilities: The outcomes of quantum events are probabilistic, not deterministic.
This challenges the Cartesian vision of a clockwork universe governed by predictable laws.
4. Holism vs. Reductionism
Cartesian View: Reductionism—the idea that complex systems can be understood by analyzing their individual parts—is a cornerstone of Cartesian thinking.
Quantum Perspective: The behavior of quantum systems cannot always be reduced to the properties of their individual components. For example:
Entangled systems must be understood as a whole rather than as a sum of independent parts.
Quantum field theory treats particles as excitations of underlying fields, emphasizing relational properties over discrete entities.
This aligns with holistic approaches and contradicts Cartesian reductionism.
5. Reality and the Role of the Mind
Cartesian View: Reality exists independently of the mind. The mind is a separate, non-material entity that does not fundamentally alter the material world.
Quantum Perspective: Interpretations like the Copenhagen Interpretation or Wigner's hypothesis suggest that consciousness might play a role in collapsing the wavefunction, implying that the mind is not merely passive but potentially integral to the unfolding of reality.
While this remains controversial, it challenges the Cartesian mind-matter dualism.
Summary
Quantum theory undermines key Cartesian assumptions by:
Blurring the boundary between observer and observed.
Demonstrating the non-local and interconnected nature of reality.
Emphasizing indeterminacy over determinism.
Valuing holistic understanding over reductionism.
Potentially rethinking the relationship between mind and matter.
These insights suggest a paradigm shift from Cartesian dualism toward a more integrated, interconnected understanding of reality, though interpretations of quantum theory remain diverse and contested.