Advanced training in Objectivism: Who does it well?

Bill,

As a follow up to the above post, in order to say something about a scientific statement, you must rely on experimental evidence. You cannot say such and such a result is metaphysically impossible without doing the experiment. That is a denial of the primacy of existence.

Jim

Post 61

Monday, November 7, 2005 - 1:17pm

James,

If you go back read Peikoff's discussion, I think you'll see that he is not saying what you took him to be saying. Peikoff's position is not rocket (or subatomic) science. He is making a straightforward philosophical point, as borne out by his following statement, "Even if it were true that owing to a lack of information we could never exactly predict a subatomic event - and this is highly debatable - it would not show that, in reality, the event was causeless." (OPAR, p. 17)

- Bill
(Edited by William Dwyer
on 11/07, 1:20pm)

Post 62

Monday, November 7, 2005 - 1:47pm

Bill,

Even if you believe that the issue is epistemological, you still have to argue that point with experimental evidence. Now, interestingly enough there are discussions over at ARI that I did not know about attempting to do just that, but that doesn't mean you can say that the Heisenberg Uncertainty Principle as stated by Dp Dq > h / 4p is wrong. Do the experiment.

The best you can do scientifically is prove that the current quantum mechanical data is not inconsistent with the Heisenberg Uncertainty Principle being an epistemological issue with some as of yet undiscovered mechanism. That is what the Bell's Inequality arguments I alluded to in the first post attempt to do. Now without having investigating those arguments carefully yet I cannot comment on them.

Now, even if the issue of the Heisenberg Uncertainty Principle turns out to be metaphysical, that does not mean that quantum events are causeless. It is baffling to me why people would want to bend scientific conclusions to fit their own philosophical preferences.

Jim

Post 63

Monday, November 7, 2005 - 1:59pm

Bill,

It is not even true that quantum mechanics poses the biggest issue for predictable causality at the micro-level. In the standard model, particles can collide in the same exact circumstance and produce a completely different set of by-products. These collisions must follow a set of conservation laws, but given the laws are followed, different combinations of by-products can occur.

This does not mean the events are causeless. It simply means that they are not predictable at the micro-level. We can categorize the possible outcomes and predict outcomes statistically, but we cannot predict the outcome of a given event.

Jim

Post 64

Monday, November 7, 2005 - 2:00pm

James, you wrote: "As a follow up to the above post, in order to say something about a scientific statement, you must rely on experimental evidence. You cannot say such and such a result is metaphysically impossible without doing the experiment. That is a denial of the primacy of existence."

No one is saying that "the result" is metaphysically impossible. What Peikoff is saying is that the interpretation of the result is. Physical science is inferential as well as experimental, interpretive as well as empirical. A "scientific statement" can be self-contradictory; it can entail an interpretation of the physical evidence that is at odds with the laws of identity and causality, in which case, one can certainly criticize it "without doing the experiment." For example, I can criticize Heisenberg's statement that "The 'path' comes into existence only when we observe it," without having done his experiment, because it is that statement itself that denies the primacy of existence.

- Bill
(Edited by William Dwyer
on 11/07, 2:18pm)

Post 65

Monday, November 7, 2005 - 2:14pm

James wrote, "Even if you believe that the issue is epistemological, you still have to argue that point with experimental evidence. Now, interestingly enough there are discussions over at ARI that I did not know about attempting to do just that, but that doesn't mean you can say that the Heisenberg Uncertainty Principle as stated by Dp Dq > h / 4p is wrong. Do the experiment."

I don't know why you are making this point. Where did I or Peikoff ever state that the Heisenberg Uncertainty Principle "as stated by Dp Dq > h / 4p" is wrong?? We never did. I thought an understanding on this had already been reached. You still seem to be missing Peikoff's point, which I thought was pretty clearly stated.

- Bill

Post 66

Monday, November 7, 2005 - 4:10pm

Bill,

Just so we're clear on what Peikoff said, I'll quote the whole passage (OPAR page 17):

Many commenters on Heisenberg's Uncertainty Principle claim that because
at the same time specify fully the position and momentum of subatomic
particles, their action is not entirely predictable and the law of causality
breaks down. This is a non sequitur, a switch from epistemology to metaphysics
or from knowledge to reality. Even if it were true that owing to a lack of
information we could never predict a subatomic event-and this is highly
debatable-it would not show in reality the event was causeless. The law of
causality is an abstract principle, it does not by itself allow us to predict
specific occurences: it does not provide us with the knowledge of particular
causes and measurements. Our ignorance of certain measurements, however,
does not affect their reality or the consequent operation of nature.

Now, there are a whole bunch of terms in here that Peikoff does not define so we have to wade carefully. But Peikoff makes clear in this passage that the Heisenberg Uncertainty Principle is an epistemological, i.e. measurement problem. And he is talking explicitly about the Heisenberg mathematical relation that you cannot fully specify the exact position and momentum of a particle at the same time. Now here is part of the problem, Peikoff probably means a different thing by "measurements" than a scientist does. He means a complete quantification or qualitative description of every aspect of the entity. The scientist means the measurements in his equations which correctly describe the behavior of the entity.

Now let me boil down what Peikoff is essentially saying: if we were to know everything there was to know about a subatomic particle, its behavior would be entirely predictable. Now what basis does he have to make this claim? It's simply a switch from the macroscopic world where that is largely true (I say largely because there are certain chaotic systems manifesting Lyapunov instability which can be represented mathematically but cannot be predicted). to a microscopic world where all the evidence says that it isn't.

Jim

(Edited by James Heaps-Nelson on 11/07, 4:12pm)

(Edited by James Heaps-Nelson on 11/07, 4:19pm)

Post 67

Monday, November 7, 2005 - 5:13pm

Bill,

OK, jeez! Peikoff is talking about unnamed commenters on Heisenberg's Uncertainty Principle, not the principle itself and their interpretation that the law of causality breaks down. And he talks in vague language about events being causeless. But he is talking about a lack of information which indicates he thinks it's an epistemological problem and in principle events would be fully predictable given perfect information. So still, what basis does he have for this claim?

(There are so many qualifications in this it's hard to know what he's saying)

Jim

Post 68

Tuesday, November 8, 2005 - 7:47am

Jim and Bill,

I only just caught the continuation of this thread. Let me give you my explanation of the Heisenberg Uncertainty Relation and then my interpretation of what Peikoff is saying and see what you think.

Heisenberg states that you can only measure (in the usual meaning of measure; i.e. with instruments) the position and the momentum of a subatomic particle to accuracies that satisfy his uncertainty relation. The classical reason for this is found in most Modern Physics books.

In order to measure the position of something, you have to probe it with, for example, light with a wavelength smaller than the position accuracy desired. Now, the momentum of light is inversely proportional to its wavelength, so the smaller the wavelength (and so the more accurate a position measurement) the greater the momentum of the probe. This will affect the subatomic particle�s momentum, due to the collision of the light and the particle. So, if the particle�s momentum was known prior to the probe, it is now uncertain by an amount given by the momentum exchange during the collision. So, basically, the measurement disturbs that which is being measured. It can be shown that the product of the uncertainty of the momentum and the uncertainty of the position of the particle cannot be less than h/4pi.

What I think Peikoff is saying, and what I think is true, is that this problem of measuring something extremely small is an epistemological problem. That is, it says nothing about whether the subatomic particle has a precise trajectory and obeys causality when not being measured. That would be a metaphysical statement and Heisenberg had no justification for saying that based on his uncertainty relation. Hence Peikoff�s statement quoted by Jim: �Our ignorance of certain measurements, however, does not affect their reality or the consequent operation of nature.�

Thanks,

Glenn

(Edited by Glenn Fletcher on 11/08, 8:15am)

Post 69

Tuesday, November 8, 2005 - 8:27am

Glenn,

As usual you have a lucid way of putting things. Yes, the Heisenberg relation is derived as a measurement phenomenon and if Peikoff circumscribes his argument to detection issues and the Heisenberg relation then yes, it is an epistemological phenomenon. The real problem in QM is only tangentially related to this, it is as you say what the particle does when it is not being measured. And it is still up in the air whether that is an epistemological or metaphysical issue.

Jim

Post 70

Tuesday, November 8, 2005 - 8:42am

Wow, Glenn! That's why there's so much primacy of consciousness smuggled into interpretations of QM! Because the interpretations are all written in terms of Heisenberg, who was dealing with the problem of what we are doing to the particle, not the particle as it actually exists!! Now the unmeasured issue still exists and has thorny problems involving causality, but not about primacy of consciousness/primacy of existence!!!

Jim

Post 71

Wednesday, November 9, 2005 - 10:07am

Jim, Bill, Glenn,

This is a fascinating discussion. In the physics department at MIT I had a hard time finding anyone who took Rand seriously or who would accept that there was any problem with the Kantian philosophical spin (no pun intended) given to the various currently fashionable interpretations of QM. In the world of Objectivism, it can be frustrating to read pronouncements from philosophers who are familiar with A is A, causality, and the primacy of existence, but don't know enough about the relevant science to explain it from an Objectivist perspective, or even enough to understand that there is a problem reconciling QM with Aristotelian/Objectivist metaphysics. I otoh know enough to follow both lines of argument, but not to weigh in definitively on them.

On the one hand there is the professor who, when I used the word "metaphysics", thought that I was talking about Shirley MacLaine, Swedenborgianism, palmistry, or that sort of thing. On the other, there is Peikoff who in The Ominous Parallels (published in 1982, years before the OPAR quote Jim listed above) attacked Heisenberg and Godel citing only a quotation, not from the works of either of them, but from a description in the New York Times of Godel's work.

These issues require someone who is knowledgable in both realms to reconcile them and tie up the loose ends at textbook length. I was very happy this summer to hear Glenn's excellent presentation at the TOC seminar which is the best thing I know of yet along those lines. And thanks for your eloquent summary of the Uncertainty problem here, Glenn.

-Bill

Post 72

Wednesday, November 9, 2005 - 1:07pm