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reality.htm
Based on  https://blogs.scientificamerican.com/observations/whatdoesquantumtheoryactuallytellusaboutreality/ 201027
by U Kyaw Tun (UKT) (M.S., I.P.C., USA),
Daw Khin Wutyi, Daw Thuzar Myint, Daw Zinthiri Han
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quantumindx.htm
UKT 201027: Do we really know what Reality is ? In Theravada
tradition of Buddhism it is Parāmaṭṭha .
For dictionary meanings see the two similar terms in PalMyan UHS
PMD0615c2.
¤
{pa.ra.mût~ta.}  m. a nonBuddhist ascetic term for
{ût~ta.}  UKT for UHT PMD0615c2
¤
{pa.ra.mût~hta.}  m. a highly beneficial (holy) beneficial effect,
deeper valuable meaning, nonchanging principle  UKT for UHT PMD0615c2
We know the dictionary meaning all right, but in actuality do we understand it?.
What Does Quantum Theory Actually Tell Us about Reality? : Nearly a century after its founding, physicists and philosophers still don’t know — but they’re working on it
From:  https://blogs.scientificamerican.com/observations/whatdoesquantumtheoryactuallytellusaboutreality/ 201027
Doubleslit experiment
Interference fringes
Wave function
Heisenberg's Uncertainty Principle
For a demonstration [Doubleslit experiment] that overturned the great Isaac Newton’s ideas about the nature of light, it was staggeringly simple. [UKT ¶]
From:  https://en.wikipedia.org/wiki/Corpuscular_theory_of_light 210718
"In optics, the corpuscular theory of light , arguably set forward by Descartes in 1637, states that light {a·lín:raún} is made up of small discrete particles called "corpuscles" (little particles) which travel in a straight line with a finite velocity and possess impetus [momentum mv , where m is the mass of the particle and v is its velocity. From this relation the kinetic energy of the particle is defined: 1/2 mv ² ] . This was based on an alternate description of atomism of the time period.
Isaac Newton was a pioneer of this theory; he notably elaborated upon it in 1672. The early conception of the particle theory of light was an early forerunner to the modern understanding of the photon [lit. atom of light]. This theory cannot explain refraction , diffraction and interference , which require an understanding of the wave theory of light of Christian Huygens .
It [Doubleslit experiment] “may be repeated with great ease, wherever the sun shines,” the English physicist Thomas Young told the members of the Royal Society in London in November 1803, describing what is now known as a doubleslit experiment, and Young wasn’t being overly melodramatic. He had come up with an elegant and decidedly homespun experiment to show light’s wavelike nature, and in doing so refuted Newton’s theory that light is made of corpuscles, or particles.
But the birth of quantum physics in the early 1900s made it clear that light is made of tiny, indivisible units, or quanta, of energy, which we call photons. Young’s experiment, when done with single photons or even single particles of matter, such as electrons and neutrons, is a conundrum to behold, raising fundamental questions about the very nature of reality. Some have even used it to argue that the quantum world is influenced by human consciousness, giving our minds an agency and a place in the ontology of the universe. But does the simple experiment really make such a case?
UKT 210718: To me, who is trained to be sceptical as a chemist, statements and ideas like "the quantum world is influenced by human consciousness" is just nonsense. Yet, I must admit, my understanding of quantum mechanics is just rudimentary, and so the best for me is keep an "open mind".
In the modern quantum form, Young’s experiment involves beaming individual particles of light or matter at two slits or openings cut into an otherwise opaque barrier. On the other side of the barrier is a screen that records the arrival of the particles (say, a photographic plate in the case of photons). Common sense leads us to expect that photons should go through one slit or the other and pile up behind each slit.
They don’t. Rather, they go to certain parts of the screen and avoid others, creating alternating bands of light and dark. These socalled interference fringes, the kind you get when two sets of waves overlap. When the crests of one wave line up with the crests of another, you get constructive interference (bright bands), and when the crests align with troughs you get destructive interference (darkness).
But there’s only one photon going through the apparatus at any one time. It’s as if each photon is going through both slits at once and interfering with itself. This doesn’t make classical sense.
Mathematically speaking, however, what goes through both slits is not a physical particle or a physical wave but something called a wave function — an abstract mathematical function that represents the photon’s state (in this case its position). The wave function behaves like a wave. It hits the two slits, and new waves emanate from each slit on the other side, spread and eventually interfere with each other. The combined wave function can be used to work out the probabilities of where one might find the photon.
UKT 210718: A wavefunction is not a wave. A wave can be a physical reality, but a mathematical function describing the wave is an abstract mathematical function. Daytoday language can no longer explain what we are getting into, and so we use mathematics to come to a state we can describe by daytoday language. Let's see what another has to say:
 https://www.thoughtco.com/definitionofwavefunction605790#:~:text=Updated%20Oct 210718
" A wave function is defined to be a function describing the probability of a particle's quantum state as a function of position, momentum, time, and/or spin. Wave functions are commonly denoted by the variable Ψ " (Greek Capital Letter Psi)"UKT: Note the word "probability". It is not "certainty". What daytoday language can describe is about certainty or truth, but what we are running into is "probability" which we cannot grasp. Now we are running into is "what the mind can comprehend" , or Jhanic states {Zaan} . Though very rare, some people like Prince Siddhartha , who would eventually become Gautama Buddha, are born with the First Jhanic state. He could comprehend what ordinary people have seen. He comprehended that [my conjecture] the bird is just picking up its food, but the worm has to lose its life. The two "actions" are not connected, but connected.
Now, we are getting into what is now Heisenberg Uncertainty Principle, which is described by a simple equation: σ_{x} . σ_{p} ≧ ħ/2 ,
where x is the position, and p is the momentum. If you are certain of one thing, the other thing becomes highly improbable.
See: https://en.wikipedia.org/wiki/Uncertainty_principle
The photon has a high probability of being found where the two wave functions constructively interfere and is unlikely to be found in regions of destructive interference. The measurement — in this case the interaction of the wave function with the photographic plate — is said to “collapse” the wave function. It goes from being spread out before measurement to peaking at one of those places where the photon materializes upon measurement.
This apparent measurementinduced collapse of the wave function is the source of many conceptual difficulties in quantum mechanics. Before the collapse, there’s no way to tell with certainty where the photon will land; it can appear at any one of the places of nonzero probability. There’s no way to chart the photon’s trajectory from the source to the detector. The photon is not real in the sense that a plane flying from San Francisco to New York is real.
Heisenberg's Uncertainty Principle
Werner Heisenberg, among others, interpreted the mathematics to mean that reality doesn’t exist until observed. “The idea of an objective real world whose smallest parts exist objectively in the same sense as stones or trees exist, independently of whether or not we observe them ... is impossible,” he wrote. John Wheeler, too, used a variant of the doubleslit experiment to argue that “no elementary quantum phenomenon is a phenomenon until it is a registered (‘observed,’ ‘indelibly recorded’) phenomenon.”
Measurement in Quantum Theory and a Theravada Buddhist's view
Unanswered questions: https://en.wikipedia.org/wiki/The_unanswered_questions 201028
" In Buddhism, unanswered questions or undeclared questions (Skt: «avyākṛta», Pali: «avyākata»  "unfathomable, unexpounded" [1]) are a set of common philosophical questions that Buddha refused to answer, according to Buddhist texts. The Pali texts give only ten, the Sanskrit texts fourteen questions."
UKT 202028: Ask a modern scientist who has studied Quantum theory, how he would explain in everyday language what a wavefunction is. I, for one, will not answer the question, but will say wavefunction is a mathematical equation to explain Reality or Paramatta , PalMyan {pa.ra.mutta.}  UHS PMD0615c2
See Ordinary Language Problem and Quantum Reality, by Jerome P. Mbat and Emmanuel Iniobong Archibong, 2012, in TIL HDPDF and SDPDF libraries:
 JPMbatEIArchibongLanguageQuantumReality<Ô> / Bk<Ô> (link chk 201028)
But quantum theory is entirely unclear about what constitutes a “measurement.” It simply postulates that the measuring device must be classical, without defining where such a boundary between the classical and quantum lies, thus leaving the door open for those who think that human consciousness needs to be invoked for collapse. Last May, Henry Stapp and colleagues argued, in this forum, that the doubleslit experiment and its modern variants provide evidence that “a conscious observer may be indispensable” to make sense of the quantum realm and that a transpersonal mind underlies the material world.
But these experiments don’t constitute empirical evidence for such claims. In the doubleslit experiment done with single photons, all one can do is verify the probabilistic predictions of the mathematics. If the probabilities are borne out over the course of sending tens of thousands of identical photons through the double slit, the theory claims that each photon’s wave function collapsed — thanks to an illdefined process called measurement. That’s all.
Also, there are other ways of interpreting the doubleslit experiment. Take the , which says that reality is both wave and particle. A photon heads towards the double slit with a definite position at all times and goes through one slit or the other; so each photon has a trajectory. It’s riding a pilot wave, which goes through both slits, interferes and then guides the photon to a location of constructive interference.
In 1979, Chris Dewdney and colleagues at Birkbeck College, London, simulated the theory’s prediction for the trajectories of particles going through the double slit. In the past decade, experimentalists have verified that such trajectories exist, albeit by using a controversial technique called weak measurements. The controversy notwithstanding, the experiments show that the de BroglieBohm theory remains in the running as an explanation for the behavior of the quantum world.
See Wikipedia: https://en.wikipedia.org/wiki/De_Broglie%E2%80%93Bohm_theory 201028
"The de Broglie–Bohm theory, also known as the pilot wave theory, Bohmian mechanics, Bohm's interpretation, and the causal interpretation, is an interpretation of quantum mechanics."
Crucially, the theory does not need observers or measurements or a nonmaterial consciousness.
Neither do socalled collapse theories, which argue that wavefunctions collapse randomly: the more the number of particles in the quantum system, the more likely the collapse. Observers merely discover the outcome. Markus Arndt’s team at the University of Vienna in Austria has been testing these theories by sending larger and larger molecules through the double slit. [UKT ¶ ]
See Wikipedia: https://en.wikipedia.org/wiki/Wave_function_collapse 201028
"In quantum mechanics, wave function collapse occurs when a wave function — initially in a superposition of several eigenstates — reduces to a single eigenstate due to interaction with the external world. This interaction is called an "observation". It is the essence of a measurement in quantum mechanics which connects the wave function with classical observables like position and momentum."
Collapse theories predict that when particles of matter become more massive than some threshold, they cannot remain in a quantum superposition of going through both slits at once, and this will destroy the interference pattern. Arndt’s team has sent a molecule with more than 800 atoms through the double slit, and they still see interference. The search for the threshold continues.
Roger Penrose has his own version of a collapse theory, in which the more massive the mass of the object in superposition, the faster it’ll collapse to one state or the other, because of gravitational instabilities. Again, it’s an observerindependent theory. No consciousness needed. Dirk Bouwmeester at the University of California, Santa Barbara, is testing Penrose’s idea with a version of the doubleslit experiment.
Conceptually, the idea is to not just put a photon into a superposition of going through two slits at once, but to also put one of the slits in a superposition of being in two locations at once. According to Penrose, the displaced slit will either stay in superposition or collapse while the photon is in flight, leading to different types of interference patterns. The collapse will depend on the mass of the slits. Bouwmeester has been at work on this experiment for a decade and may soon be able to verify or refute Penrose’s claims.
If nothing else, these experiments are showing that we cannot yet make any claims about the nature of reality, even if the claims are wellmotivated mathematically or philosophically. And given that neuroscientists and philosophers of mind don’t agree on the nature of consciousness, claims that it collapses wave functions are premature at best and misleading and wrong at worst.
Author of essay: Anil Ananthaswamy is author of The Edge of Physics, The Man Who Wasn't There and, most recently, Through Two Doors at Once: The Elegant Experiment That Captures the Enigma of Our Quantum Reality.
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