I’ve completed one out of more than 15 quantum interpretations. Formatted like this. First description of the interpretation, then the Buddhist commentary on it.
Apologies for the technical terms, to learn more, read from: Physics and Buddhism: Quantum interpretations and Buddhism Part 1: Motivation
updates will be done, the below one is fast tracked up.
Comments and additional Buddhist input on this interpretation are welcome, I might add into the book.
The story: One of the major criticism on Copenhagen interpretation is that it doesn’t define where the Heisenberg cut is. In principle, if quantum is applicable to atoms and we are all made of atoms, all the way up to the whole universe, quantum should be able to describe the whole universe. So why don’t we see superposition in daily life? Where does the wavefunction collapses? One of the mysteries to physics is the nature of the mind or consciousness (here I’ll use them interchangeably). The mind might not be physical, thus not subject to the rules of quantum, it is outside of the quantum system to look into it and collapses the wavefunction to give rise to classical notions of definite positions of particles instead of superposition of positions.
So from above, we know that in principle, a universal wavefunction can exist, collapsing wavefunction is in the theory, as well as the observer (mind) role is to collapse the wavefunction. To have the wavefunction really collapse, it is deemed as real, not just a tool for calculation as in Copenhagen. Since the wavefunction is real, collapse happens, it cannot be a local theory, as the wavefunction of an electron can in principle be extended to say the orbit of Jupiter, but once we detected it in our lab by seeing it with our eyes, the wavefunction of the electron everywhere else collapses to update the universe that there’s zero probability to find the electron anywhere else but there.
The other four properties of no determinism, yes to unique history (only one world), no hidden variable and no counterfactual definiteness follows from Copenhagen’s interpretation as there’s nothing much added except to insist that collapse happens when a mind observe quantum results.
Let’s see how classical this interpretation is. Only three out of nine properties lean towards classical preferences. A bit better than Copenhagen.
Overall speaking because it is very similar to Copenhagen, there’s little difference from the standard view, except that the wavefunction is regarded as a real thing here and superposition extends to measuring devices until it meets a conscious being.
Double-slit with electron.
Without trying to discover which slit the electron goes through, the wavefunction of the electron hits the screen, it is still not collapsed there yet, the screen goes into superposition of all possible position the electron might appear, then light from these superposition travels to the eye of the observer then to the brain, then to the mind, wherein only one of the light, corresponding to only one electron position becomes real from the collapse.
If we try to discover which slit the electron goes through, the measuring device looking on the left slit may detect or not detect the electron, and stays in that superposition of electron going through the left slit and electron going through the right slit. The superposition only collapse to give classical answer when we look into the result of the measuring device.
The silver atoms goes into the z measurement, then x measurement then z… the atoms are in superposition of all possible results until the signal reaches our brain and then our minds.
Entanglement is real and truly, weirdly non-local. Any quantum system which interacts with one another are entangled, considered to be one quantum system. Being coherent, the quantum wavefunction maintains entanglement even as the two particles move apart. Once measurement of one of the entangled particles is made and result is read by the mind, the collapse of wavefunction on one side of the particle means the other side also collapse their wavefunction and have their property 100% predictable based on the result we have here (which is randomly obtained) and the correlation between the two particles. Example, for two electrons, if they are anti correlated, one will be spin up when the other is spin down, but the results of which will get spin up or down is not determined until measurement happens. So measuring one side in the z direction and getting the result down means we know for certain the other side is spin up in z direction. Spooky action at a distance is tolerated because we cannot use it to send signals faster than light anyway.
Delayed Choice Quantum Eraser.
A lot of people[Yu S., Nikolić D. (2011). “Quantum mechanics needs no consciousness” (PDF). Annalen der Physik. 523 (11): 931–938. Bibcode:2011AnP…523…931Y. doi:10.1002/andp.201100078.] tends to want to use this experiment to disprove this interpretation. Yet, many others[de Barros, J., Oas, G. (2017). “Can we falsify the consciousness-causes-collapse hypothesis in quantum mechanics?”. Foundations of Physics. 47 (10): 1294–1308.
Andrew Knight (2020). “Quantum mechanics may need consciousness”. arXiv:2005.13317.] shows that the original objection is not valid for failing to account for the need for coincidence counter to see the interference pattern.
The result of detector clicking in 1 or 2 for each individual signal photon is in superposition until it reaches the mind of an observer. The choice of erasure or not does not impact upon the wavefunction collapse, but merely chooses between particle and wave nature of the photon. Same thing for wavefunction collapse for the idler photon is to choose which detectors of 3 or 4 do the photons choose to be detected in. There’s no significant difference from the Copenhagen’s case. See the bottom example of the fiction novel for more clarity between the choice of particle and wave nature of the photon.
De Barros also proposed in his paper that it’s basically impossible to falsify this interpretation as it would require the conscious observer to be in quantum coherence to test for this interpretation, that is being very cold or isolated from the environment.
Additional example, thought experiment Wigner’s friend.
Wigner’s friend is an extension of the Schrödinger’s cat. Eugene Wigner, one of the originators of this interpretation came out with this thought experiment to show support for consciousness causes collapse. Wigner and his friend, say Alice are in a lab. Alice does a simple Stern Gerlach quantum experiment and got either the result spin up or down. Wigner does not directly see the result of the experiment that Alice did, he asked Alice instead what’s the result and got it from Alice.
Before Wigner asked Alice, his model for the wavefunction of alice is alice sees up, experiment shows up in superposition with alice sees down, experiment shows down. It has not yet collapsed. Whereas Alice having already done the measurement, got the definite result of spin down electron. So they disagree on the wavefunction.
If the wavefunction is to be real, it should be agreed by different observers, so clearly the wavefunction should already be collapsed by any conscious observer, so Wigner cannot say that Alice is in a superposition state just because of his classical ignorance of the quantum result. The wavefunction was collapsed by Alice. That’s it. Be prepared for a radically different way of seeing this thought experiment in other interpretations.
Strength: Having the mind as a nonphysical entity to collapse wavefunction resolves the in principle everything physical should be subject to quantum. It allows for a universal wavefunction and thus a theory of quantum gravity. If this interpretation is true, it might allow physics some foothold into investigating consciousness using the tools of physics like maths, experiments, etc.
Weakness (Critique): A lot of people who critique this basically is uncomfortable with what they deem as putting two mysteries together. The mystery of quantum and the mystery of consciousness. Some are basically materialists, and having the mind being something special outside of physical world to be able to collapse the wavefunction, clearly does not gel with their belief that the mind is basically physical (brain).
Interesting cases: What happens to the universe before sentient beings appear in the universe? Can early universe process still happens with uncollapsed wavefunction? This is one of the critique too. This leads to some people proposing panpsychism (everything has some small degree of consciousness), or Integrated Information Theory (integrated information is a measure of consciousness).
In fiction: This interpretation is well known enough, and interesting enough to seep into science fiction works. For the book The Flicker Men by Ted Kosmatka, the author specifically make use of this interpretation as one of the key plot points in the story. The experimental set up is the double-slit experiment wherein if there’s a consciousness trying to see which slit did the particle goes through, the interference pattern disappears. This is used in the novel to first test between people who are blind vs people who can see and they found that blind people do not cause the interference to disappear. Then they found that some people even with good eyesight do not cause the interference to disappear, indicating that they do not have real consciousness or mind, that they are mere robots or programmes.
If true, it would be a very useful test to directly test for this interpretation. Yet, obviously no one in the physics community took it seriously. Why? Because there’s a misinterpretation of the double slit experiment by the author. The wave-particle duality transformation is different from collapse of wavefunction. Whether the electron behaves like a particle or wave in the double slit depends on experimental set up, that is, is it possible to detect which way the electron goes through? Once we put the measuring device near to the double slit to try to detect the electrons, they become particles. The experimental set up itself chooses the wave or particle behaviour. Once the set up is done, as analysed above, the only collapse of the wavefunction is to determine if the electron had gone to the left or right side of the slit, the screen shows only two vertical lines of electrons passing through two slits where we know which slits each electrons passes through.
This can illuminate the delayed choice quantum eraser explanation above too.
A recent paper[Narasimhan, A., Chopra, D. & Kafatos, M.C. The Nature of the Heisenberg-von Neumann Cut: Enhanced Orthodox Interpretation of Quantum Mechanics. Act Nerv Super 61, 12–17 (2019). https://doi.org/10.1007/s41470-019-00048-x
] (2019) argues that delayed choice quantum eraser may imply an extension of this interpretation to include observers from outside of space and time. The delayed choice quantum eraser according to them shows that the collapse of wavefunction is outside of time, much like entanglement shows that it is also outside of space. So if wavefunction collapse is due to conscious observers, then it should be outside of spacetime and called the universal observer. They call their interpretation as the Enhanced Orthodox Interpretation. Their paper misidentify the consciousness causes collapse as part of Copenhagen interpretation and regard Copenhagen as the Orthodox interpretation hence their name. This goes to show the need for an popular book categorising the various interpretations of quantum. I wouldn’t honour their interpretation with a new page yet, as it’s very new and doesn’t seem to worth the effort to distinguish it much from this consciousness causes collapse interpretation.
There’s a second fiction book which touches upon these concepts, Stephen Baxter already had the notion of the ultimate observer in his book Timelike Infinity which was published in 1992. The reasoning is that using the Wigner’s friend example, if everyone’s wavefunction can be represented by someone else, going all the way up, wouldn’t there need to be someone ultimate at the end of time (Timelike infinity) to observe everything and collapse all the wavefunctions to the past and actualise reality? The friends of Wigner became a religious cult which was bent on sending a message to this hypothetical observer at the end of time instead of using their time travel to the past to help the past humans to defend against the future invasion of humankind by aliens.
Right off the bat, there’s a lot more acceptance of this interpretation amongst Buddhists and basically, all religions which don’t hold materialism view that the mind is the brain, or a function of the brain and is wholly physical or reducible to physical.
The Buddha didn’t side with either materialism or dualism. In sutta MN 72, when asked is the body and soul the same or different, the Buddha answered: That is not my view.
Buddhism as a whole does lean more towards dualism rather than materialism due to the teaching of rebirth. The materialists due to identifying the mind as the brain cannot conceive of the mind surviving the death of the brain as apriori conclusion from their philosophy. The dualism commonly misattributed to Buddhism is due to the classification of the five aggregates into one of form (physical body), and four of mind (feelings, perception, volitional formation and consciousness). It is not uncommon to see Buddhists leaning more towards dualism, but it’s good to remind oneself of the above undeclared views of the Buddha.
What the Buddha taught was dependent origination. In the 12 chains of links, there’s interplay of conditioning from body to mind and mind to body and mind to both body and mind, and so on.
Referring to this source, the most relevant link to this interpretation maybe consciousness conditions name and form. Form being the physical body, name being feeling, perception, volition (cetana), contact (phassa), and attention (manasikara).
Without further reading, this seems to fit into the notion that consciousness causes collapse of wavefunction and actualize reality into physical form.
Whereas the original meaning is: “It was said ‘with consciousness as condition there is name-and-form’. How this is so, Ananda, should be understood in this way. If consciousness were not to descend into the mother’s womb, would name-and-form take shape in the womb?” “No, venerable sir.”
That consciousness determines what kind of body and mind the being produces, whether humans, animals, hell, gods, etc.
So on the whole, while there’s no objection to this interpretation from Buddhism due to no materialist view held, there’s also no concrete support for it, unless you are willing to take the link of consciousness conditions name and form to extend it to collapsing wavefunctions.
Overall, this is one interpretation that Buddhists are comfortable with.
There’s a few more interesting observation. With the addition of the Buddhist point of view, we can deem that the Extended Orthodox Interpretation’s observer can be the 2nd Jhana Brahmas realm beings who would survive the destruction of this universe, thus presumably is outside of this universe. Or perhaps this role is taken up by the formless Brahma realms, in particular the sphere of infinite space. Or perhaps not, according to Buddhism, the formless Brahmas cannot hear or see due to not having any physical body. That’s why the Buddha couldn’t teach his previous two meditation teachers Alara Kalama and Uddaka Ramaputta as they both had been reborn into the formless realms by then. Thus, most likely not.
The concept of an observer from outside of the universe also solves the problem of collapsing the wavefunction before the first being is reborn back into the world, allowing the early universe to proceed as predicted by general relativity, nucleosynthesis and so on.
Another interesting possibility due to the addition of Buddhist concepts is the divine eye. It might be so finely tuned so as to try to observe which slit did the electron tries to go through in the double slit experiment, without the presence of any physical measuring apparatus to alter the experimental set up and cause decoherence. If the which path information is obtained for the electron, the interference must disappear and this counts as a concrete show of the effects of consciousness on physical objects other than the everyday link of craving and clinging (mind objects) drives our action and speech (becoming).
As stated earlier, there’s no obligation from Buddhism to insist that the wavefunction must be collapsed by consciousness or not. What’s more important is to practise mindfulness of the subjective experiencer, to observe the observer. To see cause and effect within the mind and body internally, to be able to see impermanence, suffering and not self nature of the observer. To observe no observer is there in the first place (due to no self)!