Thoughts on Judaism

Sunday, March 13, 2005

Copenhagen, Heisenberg and Apologetics

A quick look here should be enough to sober a person on the danger of using obscure scientific theory in apologetics. Please see my previous post's links for review of the QM subject, and the Chabad Rebbe's (CR) letter, refering to the Heisenberg principle of uncertainty.

Not enough that they want to apply these QM concepts to the physical macro world, but they want to learn from that speculation all sorts of Torah concepts, whether they are Torah or not.

For review: Heisenberg stated that the more precisely we measure the position of a subatomic particle, the less precisely we can measure its momentum, and vice versa. Hence, we can only determine the position or momentum within a range, but not precisely. Hence, we cannot conclude that cause "A" will always place the particle at point "A", as a conclusive effect. (Deeply oversimplified, but simply google the subject for more in depth discussion.)

The Copenhagen group, Bohr, Schrödinger et al, based on the double slit experiment, concluded that as one measures the wave or particle, the wavefunction collapses, making further measurement impossible. The implication is that one can measure either particle or wave, but not both. We cannot determine which particles go through which slits through cause and effect. If we open both slits and fire photons at only one of them, we would expect to lose the wave behavior, BUT THAT IS NOT THE CASE EMPIRICALLY. Schroedinger described it with the famous cat thought experiment.

The linguini logic of apologetics goes something like this (I am picking on Chabad, but others of you , Jewish and non Jewish, you know who you are):

1) QM proves that cause and effect are not necessarily linked. Each effect is only the most probable, not the necessary effect of the cause. Hence, miracles are naturally proven to be possible, though not probable. Naftali Berg Z"L, in B'or HaTorah vol9 page 47, indicates that the CR told him that this was an OBJECTION to using Heisenberg in apologetics, since it obviated the MIRACULOUS nature of miracles and made them only improbable events.

2) Prayer can affect things though our intention, just as, in Copenhagen, the observation changes the reality.

3) Reality is, itself, determined by observation, Aidus, as Copenhagen implies. Hence, we cannot trust our own observations, but Torah's edicts, as it is our observation that makes the reality real.

(Note: while some will claim this is a "straw man", I assure you that I have heard each of these arguments proposed in all seriousness. Follow the links, and you will be amazed at the apologetic acrobatics.)

I would point out some of the more obvious flaws in using this information in this manner. Please feel free to add any others you see fit (or question mine).

a) Heisenberg only applies to SUBATOMIC particles. We can know both position and momentum precisely with a car, a spaceship or a planetary body for instance. The Planck constantis key to understanding the scale. To say that Heisenberg removes the relationship between ALL CAUSE AND EFFECT is presumptuous and not supportable. Even the cat gedanken is only theoretical explanation of their view of how this could affect the macro world, not established reality. I am amazed that, given what Berg said in 1995, still maintains this on its website, though the Mindel letter from the CR seems to support this concept.

b) The CR was at the University of Berlin in the 1930's when and where QM was just being born in the layman's mind. This type of speculation would have been prominent discussion at that time. Still, the context of the Mindel letter does not completely imply that the CR is on board with it, only that the arguments of scientists are out of place, considering the principle. His point is that determinism is no longer certain in science whereas Torah is certain in reality and therefore, science cannot disprove Torah. True enough, but science can call interpretations of Torah (and every word and halacha of Torah requires interpretation*) into deep question, even based on likelihood. "You can't prove it" sophistry aside, the Torah scholar must take a position, "this is wrong by Torah standards" or "this is acceptable by Torah standards", on questions of science. Just to say that the science shows the world to be undeterministic is not a strong or supportable argument.

c) Copenhagen DOES NOT imply that the observer causes the reality. It only implies that the observer brings determinism to the system. The observer has no control over WHAT WILL BE DETERMINED, only that the observation establishes one of the possibilities as reality. The cat experiment makes this perfectly clear. In the moment before observation, the cat is both alive and dead in Schroedinger's estimation, and upon observation it will become one or the other, but the observer has no way of CONTROLLING WHICH will happen.

d) Copenhagen has always been weak. Dr. Afshar's challenge is devastating to Copenhagen. In short, Copenhagen is counterintuitive, violates the Theory of Relativity, and is likely to die the death of the Ptolemaic astronomy system. In short, Afshar shows that he can observe the wave behavior and measure no change in the particle behavior at the same time. In the modified double slit experiment, he blocks the minima of the wave pattern. In observing the particle behavior, according to Copehagen, the wavefunction collapses and the wave behavior cannot be observed. Hence, particles should be absorbed by the blocked minima, since they are no longer "real". He claims though that experiment data shows no difference, indicating that the wave pattern minima still exist, even though he is measuring the particle behavior. When Copenhagen is disproven, what will become of the apologetics built on it?

e) Even without Afshar, there are other possible explanations, aside from Copenhagen. Since they are not so conducive to apologics, however, they are not considered. Yet, it is incorrect to ascribe anything approaching scientific consensus to facts based on Copenhagen, or even indeterminacy, as with Einstein and Bohm.

In short, using Heisenberg or Copenhagen for the purposes of apologetics is short sighted. Look at the Ramban at the beginning of Parshas Tazria to see how disproven science in apologetics looks several centuries later.

* Note: Above I stated that all of Torah requires interpretation. I will bring two examples. In the case of a thief breaking in, the Torah says that the matter depends on whether it is day or night. The Chachamim say that this is allegorical and refers to whether the victim is "as certain as daylight" that the thief is not going to kill him, as with a father breaking in on his son. In the case of a Motzi Shem Ra, the Torah states that the proof that the victim's father brings is to "spread out the sheet" that proves her virginal bleeding. The Chachmim interpret allegorically that this means to indicate that the father of the victim carries a high burden of proof. (This is because the proof that the Torah recommends is very weak, since it can be easily faked. Perhaps the Torah meant just that, that the father's burden proof is very low, but the Chachamim interpret as they do. The point is that it is, in all respects, an interpretation of the Rabbis, overriding what would be the clear words of Torah.) This being the case, anytime we are challenging the "Torah", we are, in effect challenging an interpretation of the "Torah". The clear resolution of halachic issues by expounding is the basis of Talmud, Rishonim, Acharonim and later discussion. We have every right and responsibility to ask how they came to any conclusion, and what they meant ex-cathedra, and what they were giving as examples. Watch out for my "infallibility" rant, soon to follow.


  • Quantum mechanics is doing well. It is supported by a huge body of experiments and practical applications. It has its own causality and it is well known that there are no hidden variables.

    The reason we do not often see quantum mechanical phenomena at mundane scales is not because of size. It has to do with quantity, coherence, and statistics. Even so, there are plenty of macro scale quantum phenomena.

    The fundamental question that you might ask yourself is: Is the universe an accident, or is it deliberate? Either way, it seems that you need to have quantum mechanics.

    Notice that the existence of free choice and Hashem seem to require something other than classical determinism. The brain may also be a macro scale quantum device.

    What is your highest attained academic degree and in what subject was it awarded? If doctorate, what is the title of your thesis?

    By Anonymous mcn, at 11:41 PM  

  • Point by point, by paragraph

    1) Agreed. Causality and locality, however, as defined by relativity was one of E's main objection, the famous "spooky action" comment.

    2) We are discussing interpreations of observable fact, not the observations themselves. There has not yet been a differentiation between the theories at the macro level, beyond gedanken.

    3) No one is proposing the elimination of QM, only the understanding of determinism. They are not synonymous.

    4) Mishmash

    5) Identifying information, danger Will Robinson! We will have to be satisfied to let the points speak for themselves.

    By Blogger Rebeljew, at 1:35 PM  

  • This is obviously not rebeljew's subject. Here are a few examples.

    rebeljew says: "Heisenberg only applies to SUBATOMIC particles."

    Wrong, heisenberg has nothing to do with size except that it is smeared over in systems that have a lot of incoherence. (For the mathematically inclined, heisenberg has to do with commutation for certain types of variables).

    rebeljew says: "There has not yet been a differentiation between the theories at the macro level, beyond gedanken."

    Wrong again. Macro scale quantum experiments were done about twenty years ago. I was at one of the places were they were being done.

    rebeljew says: "Dr. Afshar's challenge is devastating to Copenhagen."

    And wrong still again. rebeljew not only failed to recognize an obvious crackpot, he even cited him.

    And then to verisimilitude and agenda:

    "I am picking on Chabad"

    rebeljew is (i) citing a few crackpots and (ii) utterly misrepresenting the Rebbe's writings on these subjects.

    Indeed rebeljew is picking on Chabad and his agenda is clearly to push people away from observance.

    To that, let it be clear that:

    There are plenty of actual scientists who are frum and even some who became frum after becoming scientists.

    If you need a question answered, post it to ask moses, and ask them to forward it to a frum scientist.

    By Anonymous mcn, at 10:01 AM  

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