Can Quantum Probability be Reconciled With Cause-and-Effect?

[RArvay]

Summary:

***I am not a physicist.
***In the following commentary, I address the topic of the gap between quantum theory and relativity theory, more specifically, between chance and causation. This commentary is based upon various presentations made by physicists for general public consumption, and I extend it to express conclusions which I have made.
***In this commentary, I ask what, if anything, precipitates a truly random quantum event?
***Is there an unseen causative factor preceding each quantum event, or only the abstraction of statistics and pure chance?
***Does the pure chance factor, at the quantum level, manifest itself in large, macro events, or does quantum randomness “average out” into overall neutrality?
***Is there a foundational orderliness of nature? Is that foundation stable?
***Sir Roger Penrose suggested that consciousness may provide a clue to reconciling QM with GR. What are the possible consequences?
***Can consciousness exist without autonomous volition (free will), or would that constitute a paradox?
*** The key paragraph in this commentary is this:
It is the precise moment of this deviation (for example nuclear decay, or perhaps quantum tunneling) that is so very crucial. That precise moment highlights the break between causation and chance. We are faced with the question: at that precise instant, why does that particular atom alter its usual behavior? What is different at that instant? What dynamic applies now that was not manifest before?


===============

One familiar way to think of deterministic cause and effect is with a row of dominoes, placed in a line, standing on end, such that when the first domino is tipped over, it tips over the second, which tips the third, and so on, until all the dominoes have fallen.

This scenario illustrates a series of predictable events which, according to the strictly deterministic view, is inalterable once the first domino is tipped (barring external influences).

Einstein’s view of the universe seemed to be deterministic, albeit in vastly more complicated form, but in principle the very same.

Then along came quantum randomness, which Einstein never accepted. His objection seems to have been that, in quantum physics, certain events at the subatomic level can randomly occur without any immediate, identifiable, preceding cause. For example, a radioactive nucleus can spontaneously decay. The precise moment of that decay is utterly unpredictable, although a range of time can be specified in which that decay has a given percentage chance of occurring (for example, fifty percent within the half-life).

If one follows the implications, these two views of the unfolding of events in the universe seem utterly contrary and incompatible. Chance events that have no specific cause are anathema to determinism.

In an attempt to reconcile them, one might propose that the universe has both deterministic and random aspects, a sort of mixture of water and oil. In other words, the chain of dominoes can be interrupted by the occasional quantum domino which does not fall; there being so very many dominoes in such intricate arrays that on the whole, the outlier domino does not greatly affect the overall pattern.

In other words, strict causation might be modified to include the word, “probably.” If I strike a ball with a bat, the ball will “probably” fly according to a calculable trajectory, give or take an electron or a trillion. Given the vast numbers of quantum events in play, we expect the ball to fly extremely closely in accordance with the Newtonian calculations.

At the level of the individual atom, however, this reconciliation leaves the comfort zone, and the contrast with causation becomes more glaring. Although the atom will usually behave according to expectations, on occasion it is fully expected to deviate in a manner that cannot be precisely predicted, nor accounted for except in statistical terms.

It is the precise moment of this deviation (for example nuclear decay, or perhaps quantum tunneling) that is so very crucial. That precise moment highlights the break between causation and chance. We are faced with the question: at that precise instant, why does that particular atom alter its usual behavior? What is different at that instant? What dynamic applies now that was not manifest before?

If we say that the difference is one of pure chance, then we are speaking so abstractly that we are more rationalizing than explaining. Clearly, even randomness has parameters. There is a reason why a radioactive atom is unstable as compared to, say, an atom of lead. The unstable atom is perched on an edge. At some point in time it falls off, or decays. Why at that particular point, as opposed to another? What was the selecting factor? Did anything happen in the instant (before the decay) that precipitated the random decay?

Apparently not, according to quantum physics.

I speculate that this is why Einstein never accepted the principle of quantum probability. There seems to be no solid basis underlying it, but only the abstraction of numbers. Einstein declared that “something more” must be in play, but not independent chance unconnected to other physical (deterministic) factors.

I’ll speculate a step further. Einstein seemed to believe, as I think most scientists do, that natural law is underlay by a principle of order. As Schrodinger’s thought experiment illustrates, randomness at the subatomic level can manifest itself at the macro level in the world of our common experience. Unpredictability inside the nucleus is unpredictability on the larger scale, even of the universe itself. Is order itself unstable?

When Einstein asked, “Is the moon where we see it?” he was not being facetious. He well knew that the standard deviation of statistics would place the moon within an electron of where we see it, give or take a proton. However, in principle, quantum physics does not impose any particular location on the moon, just as it imposes no particular location on any one electron.

This example may seem trivial in practice, but it points to a fundamental principle that Einstein (in my very fallible opinion) saw as violating the notion that physical reality is underlay by foundational order, an order that is stable.

Alan Guth provides an illustration. When he declares that anything that can happen must happen, and must happen an infinite number of times, then he is (whether intentionally or not) portraying a universe where nothing happens. In other words, the universe is statistically stagnant. Here and there, local events occur, but in the grand scheme of things, watching the universe is like watching static on a television screen. Stated another way, if pure random chance is at the heart of natural law, then according to Einstein the universe (as I interpret his writing) is absurd, and not subject to human discernment.

One abstract way of attempting to reconcile quantum probability with causation is to think of a hidden parallel universe from which occasionally certain events “pop out,” so to speak, from behind a sort of screen which hides that other universe, somewhat in the manner of a stage director poking (or whispering to) an actor from behind. This notion of unseen causation would, if true, provide that “something more” that Einstein may have spent his final days working on while trying to unify quantum and relativity theories.

A brief comment made by Sir Roger Penrose in an online video may eventually turn out to have been a profound contribution to the search for unification. The subject matter concerned what many regard as the greatest mystery of physics, that of our inwardly experienced human consciousness, a phenomenon that seems to defy formulation.

Penrose mentioned (I do not recall his exact words) that the key to solving this mystery may be the discovery of an as yet unsuspected theory that lies in the gap between quantum theory and relativity. That undiscovered theory may both unify quantum physics with relativity, and also provide a basis for understanding consciousness.

So far into this brief statement I have attempted to stay within the straight and narrow of accepted, or at least acceptable, science. There is a gap between relativity and quantum physics. I propose that there exists a foundational level of physical reality, a level which I believe rests on the bedrock of a natural order that permits no fundamental absurdities.

The gap, therefore, is a gap which I believe is filled by nature in a manner which we have not yet discerned. I propose that the undeniable existence of personal consciousness is a clue to what fills in that gap.

Consciousness, however, presents us with an absurdity, unless there is yet another principle which clears away that absurdity. The gap-filling theory must include not only an explanation of conscious awareness (as we ineffably experience it), it must also include what is presently considered the heresy of free will, or individual volition.

I hasten to add that while I have met or corresponded with numerous people who deny that free will can possibly exist, I have yet to meet one who professes to live his life on the assumption that he has no choice whatsoever in the decisions he makes.

The absurdity of consciousness without free will is that it would make us mere observers in our own lives, but not participants. Can there be science if that is the case?

The foundational existence of both consciousness and free will might explain the fine tuning of the universe.

At this point, I have entered into the realm beyond present-day science, so I shall leave off.

[menoma]

When Einstein asked, “Is the moon where we see it?” he was not being facetious.

Especially not if he never actually said it. The only other place one finds this quote, at least online, is in one of your own books. Can you provide a cite from another source? The common understanding is that he asked something along these lines: "Isn't the moon there when nobody's looking at it?" Reported originally, I think, by Abraham Pais. Very different question.

[Joy Christian]

Can Quantum Probability be Reconciled With Cause-and-Effect?

Yes.

They have already been reconciled with cause and effect. See, for example, here and here.

Further details and extensive references can be found here.

***I am not a physicist.

That is no excuse. It is like saying: "I am not a theist and I know nothing about God, but I nonetheless want to go on, and on, and on, and on talking about God."

If you want to talk about physics, then learn some physics and some mathematics. "I am not smart enough" is no excuse.

[RArvay]

Thank you for the references.
I will look into them, as I have into so many other references on the topic.

I think I am accurate in saying that Einstein never did accept that there is in nature
a principle of pure probability.
While I speculate as to the reasons why, I think my speculations are reasonable.

The "moon" example was in that context, a rhetorical (of course) question.
I don't remember where I got the quote, but it was probably in a layman's article,
and as worded, it addressed the question of quantum uncertainty.

My disclosure of not being a physicist alerts the reader right away that he may not wish
to read any further, thus avoiding a waste of his time. I consider it a simple courtesy.

My commentaries in this forum are just that, commentaries, not formulations.
They do tend to be metaphysical and philosophical, but also relevant and of interest to
some physicists.

Physics itself is underlay by unprovable axioms without which it would be pointless to study nature.
The history of science is one of paradigm shifts, based on new evidence coming to light,
and which challenged some of the old assumptions.

I cannot help but feel now, as I did in my college science courses, that anyone who questions
the basic assumptions of science is doing no harm, and may in some way have a beneficial influence,
however indirectly.

If my comments are counter-productive to the purpose of this forum, then of course I shall withdraw.

[RArvay]

Greetings;

I read through the links provided by Joy Christian, but did not find any clear cut answer to the specific question I highlighted in my earlier post, which is this:

It is the precise moment of this deviation (for example nuclear decay, or perhaps quantum tunneling) that is so very crucial. That precise moment highlights the break between causation and chance. We are faced with the question: at that precise instant, why does that particular atom alter its usual behavior? What is different at that instant? What dynamic applies now that was not manifest before?

If anyone would shed light on this in layman's terms, I would greatly appreciate that.

Thanks in advance!
.

[Joy Christian]

I read through the links provided by Joy Christian, but did not find any clear cut answer to the specific question I highlighted in my earlier post..

Have you ever tossed a coin? Suppose a coin is tossed a large number of times. Then how many times will it land heads and how many times will it land tails?

More importantly, what causes the coin to land heads some times and tails other times?

In this simulation the vector u represents a classical nucleon in a specific initial state, just like the coin in the above example. The nucleon is then tossed a large number of times. The resulting correlation between the spins of the constituent particles observed at two remote stations is exactly that predicted by quantum mechanics, even though the nucleon decay is treated entirely classically. The process demonstrated in the simulation is thus manifestly causal, and locally so.

I hope you are not proposing that even the classical coins are commanded by God to land heads some times and tails other times.

[RArvay]

Thank you for the reply.

Please correct me if I am wrong, but . . .
Coin flips are subject to pseudorandomness, not quantum (true) randomness.
Although we cannot predict the coin toss, that is only because in practice we are unable to calculate all
the factors involved which determine the outcome. In principle, the outcome is deterministic.

As I understand QM, however, the events at the quantum level are truly random.
No matter how much we know about, say, a given radioactive atom,
we cannot predict the precise moment of its spontaneous decay, but only
the chance that it will decay in any given moment.

The coin, then, is governed by a sequence of determined events, as in the domino example.

The precise moment of spontaneous radioactive decay seems to be an entirely different species,
the event not being traceable, and the moment being selected not by a "domino" so to speak.

Have I got it all wrong?
Has there been discovered the "something more" to which Einstein referred in his rejection of QM?
Does the atom decay because a specific --in principle identifiable-- event tipped the domino? (so to speak).

Thanks again for responding.
.

[Joy Christian]

Have I got it all wrong?

No, you have it right, more or less.

Has there been discovered the "something more" to which Einstein referred in his rejection of QM?
Does the atom decay because a specific --in principle identifiable-- event tipped the domino? (so to speak).

Einstein did not reject QM. He only sought a locally causal underpinning of the quantum phenomena.

I have already given you the answer to your question, with detailed references and a clear cut explanation in layman terms. The answers to your questions are: Yes and Yes. You don't understand my answer because you have zero technical background in physics and mathematics. Because of that no one can help you understand.

[RArvay]

I deeply appreciate your having tried.
Thank you.
.

[friend]

Cause and effect is another way of saying premise and conclusion of logic. In my thesis I describe reality as a conjunction of all facts (not specific to what those facts are). This conjunction can be written in terms of material implication (which is the premise-conclusion relationship, or the cause and effect relationship). I use the Dirac measure to relate material implication to probability distributions. This enable the ability to derive quantum theory from logic alone. So, yes, quantum theory can be reconciled with cause and effect. Details at:
http://www.logictophysics.com