Physics and Philosophy

Joe, I don't exactly want to open that worm can, but the thing is that all these various subjects seem to narrow down to those very questions. I think that when the scientists start losing their perspective they get to some very dubious conclusions, such as the ones I mentioned above. I think the Objectivist viewpoint is not being "faithful" or "ignoring science" when it states these fallacies. I think it is just bad science being exposed.

Post 61

Wednesday, April 26, 2006 - 12:46pm

Thanks Glenn for the double slit commentary, I found it very interesting.

However, I found Bell's explanation very weak.

"Is it not clear from the smallness of the scintillation on the screen that we have to do with a particle? "

No, it is not clear.

"And is it not clear, from the diffraction and interference patterns, that the motion of the particle is directed by a wave?"

No, it is clearer ( to me) that we're dealing with some form of particle-wave duality.

However, you could argue from UNauthority, that I'm wrong.

Bob

Post 62

Wednesday, April 26, 2006 - 1:01pm

Kurt,

Science does not 'claim' anything. Science, by definition almost, continually searches for truth and refines and sometime refutes itself, then improves. It is for the reason I have "faith" in science personally.

Objectivism has a doctrine, science does not - or at least it's a moving target. One scientist claims A, another claims B.

Bob

Post 63

Wednesday, April 26, 2006 - 2:40pm

Bob Mac,

In post #59, you wrote: "Stephen wrote: . . . "

No, I didn't write that. Did you think I did? Did you think I agreed with what I quoted there about the nature of chance and identity? Did you think I disagree with you? Why?

Stephen

Post 64

Wednesday, April 26, 2006 - 3:26pm

Stephen:

You included this in your post (57) and attributed it to Allan Gotthelf.

"Things in the world come to be by nature---by the natures of the individual acting entities."

I was not making any assumptions wrt to your agreement or not. I was stating that I don't see how the statement from Gotthelf has any real meaning.

To me, the statement is equivalent to "Things act and interact according to their "nature" whatever that may be." How could anything, ever, contradict that? To me it's meaningless/doesn't make sense.

That was all I was saying.

Bob

Post 65

Wednesday, April 26, 2006 - 3:44pm

Joseph Wrote:

So the question isn't which competing model is better. The question is what standards are used to pick those models, and if there are standards, whether those standards are rooted in philosophy.

Very succintly put, and it illustrates my biggest problem here very well. If Objectivist-compatible evaluation standards produce a superior model, then fine. It must be shown to be superior to the other models that contradict Objectivism.

If not, well there's a problem isn't there? Either some part(s) of Objectivism are incorrect and/or we need more study and data to figure it out. ASSuming Objectivism is correct, to me, is just foolish.

Yes, I have a bias because reading Rand, I find I simply cannot accept many things - another thread sometime maybe. I admire the reason, logic, and many other elements, but strongly disagree with many of Rand's conclusions (and even premises).

BOb

(Edited by Mr Bob Mac on 4/26, 3:56pm)

Post 66

Wednesday, April 26, 2006 - 4:31pm

Bob,

Glad you agree with what the issue is.

You say "Either some part(s) of Objectivism are incorrect and/or we need more study and data to figure it out."

So here's where an understanding of philosophy is important. BTW, did you read my "Fundamental Premises" article I linked to above? The point I made there, and it's worth reading in my humble opinion, is that the true fundamental questions that philosophy answers cannot be judged by the evidence, as they are the standard by which we evaluate and even understand the evidence.

If you believe God plays an active role in controlling the forces of the universe, there can be absolutely no data that disconfirms it. An atheist and a theist can both point to data and say "See...it fits with my theory". Or what if you think everything is an illusion? Trying finding counter proof to that.

It's not like science in that way. A scientific theory can make a prediction about the nature of the world, and when the data doesn't match, you know there's a problem. The fundamental premises of a philosophy are able to "account" for any data.

But even that ability is based on philosophical premises. For instance that there is something out there, and it's not just an illusion. Or that contradictions don't exist. Or that causality exists, meaning things act the way they do for actual reasons, and thus predictions are possible if you understand the reasons. And there's a whole lot more. All of this is deeply philosophical. Scientists don't always admit or recognize it, but it doesn't change it.

What happens if one had a different philosophy? What if you believe contradictions in reality existed. Then when you see the result of your experiment, you could simply say that it happened in both ways, but we're only able to detect the one. Or maybe your truth is different than my truth.

What if you believed causality was an illusion, and things just happen by chance. You wouldn't even bother looking for causes. If someone found them, you could remain skeptical. If ever they couldn't solve a puzzle, you could say "See...I told you!".

A philosophy has multiple parts. Some are these fundamental premises, which can't be proven or disproven, because they set the standards for what a proof or disproof is. But there are derivative premises, which seek to explain how it works.

As an example, a theory of perception could claim that we directly perceive reality through a causal, and therefore accurate, means. One could add additional details, explaining the causal mechanism. Light reflects off of objects, hits sensors in our eyes, triggering our nervous system to send signals to parts of the brain. These derivative premises, which seek to integrate what we know about reality, can be questioned and analyzed. In other words, we can argue about the mechanics of perception, but not the more fundamental conclusions. If you question the validity of the senses, you can't use the evidence of the senses as proof. But you can question the means by which it's done.

This is not to say that a philosophy can't be judged. It only says that truly fundamental premises cannot be tested by experiment, as they will interpret the results. This isn't the philosophical bias that some worry about. This isn't that they'll selectively ignore data, or exaggerate the importance of it, or anything like that. I mean the data will completely, 100% conform to these premises, and will actually appear to validate those premises.

Judging a philosophy takes more than that. It can be tested for logical consistency. It can be judged on how effect it is in practice. It can be judged by whether it can be consistently practiced. And more, I'm sure.

So going back to the science thing, the question is which philosophical premises of Objectivism are being used as the foundation of science. Are those premises something that can be proven? Or are they required to even discuss proving something. We can certainly have that discussion, but not while you still struggle with the understanding that philosophy is inescapable, even within science.

Post 67

Wednesday, April 26, 2006 - 5:29pm

Joseph,

I'll reply more when I get a chance. Thanks for the post. Let me just mention one agreement I have with what you're saying and a problem for now.

"Or that causality exists" (as a premise) - I agree.

Where is the line of reasoning that ends with causality must exists always, everywhere, in every instance?

The universe is not required to comply with this, and there's at least some good evidence that it doesn't.

Causality is amenable to testing. Does that exclude it as a premise? I don't really know, but it can be tested even though we don't have the final answer yet.

I read your fundamental premises article. I don't think causality is something that cannot be reasonably tested.

Bob

Post 68

Wednesday, April 26, 2006 - 6:05pm

Bob,

Let me just quickly point out that for every evidence you find of a lack of causality, I see evidence for a flaw in the current explanation, and a hidden variable. So how do you test for it? Keep in mind, as I said before, that this is not me ignoring the evidence. I'm not ignoring it at all. The evidence convinces me that we have to look harder, and it's the basis of my belief that the theory needs more work.

Also, the problem with suggesting causality is not always true is that you have to explain how things happen. If it's not due to the nature of the object itself, then it must be something. If it's an inexplicable force, which we can call "magic" or "god", that's one "explanation", but it's entirely philosophical. You have to start with the premise that things are allowed to "just happen".

Post 69

Thursday, April 27, 2006 - 5:59am

Joseph,

I understand what you're saying

The evidence convinces me that we have to look harder, and it's the basis of my belief that the theory needs more work.

I think it's apparent that the theories need more work. AFAIK, we don't have the theory of everything yet.

Also, the problem with suggesting causality is not always true is that you have to explain how things happen.

Well, we're coming down to definitions here now I think. You can argue that causality is self-evident, necessary, not testable and so on, but fundamentally I beleive it is a perception - much like time. Historically, perceptions are notoriously incomplete and counter-intuitive explanations turn out to offer a more correct, deeper perception/understanding. Not because of hidden variables necessarily.

Causality, or our current notion of it, is simply not immune to this. Cause-effect-time-locality have a myriad of hidden assumptions based on our macroscopic bias that is most certainly unreliable at best, and at worst, in some cases, is dead wrong. I understand that you need a standard/philosophy to evaluate perceptions and form knowledge, but our notion of causality is not fundamental.

This is not a "mystical" attitude, contrary to your repeated assertions.

Bob

Post 70

Thursday, April 27, 2006 - 7:57am

Just a quick couple of points concerning this very interesting thread:

1) We need to think deeply about what constitutes a cause. Aristotle had a rich understanding of what explains the existence of some entity or phenomenon. Four categories, with a simple example, are: a) material cause -- the brinks, wood etc. of a house; b) formal cause -- the arrangement of the bricks, wood, etc. of a house, not a pile of stuff but a certain design; c) the efficient cause -- the carpenters, mason, electricians, etc.; and d) final cause, the purpose of building the house.

The Age of Reason ironically brought a narrowing of the philosophical understanding of cause, usually a reduction of it to efficient cause -- billiard balls hitting one another, or even worse, as with Hume rejecting causality altogether in favor of causation or a constant conjunction of events. That meant that with the advent of quantum physics a lot of philosophers didn't know how to approach cause and thus many endorsed a radical skepticism.

Thus it is necessary to reexamine what constitutes a cause, that is, what entities, their actions, attributes and the like bring about other entities, their actions, attributes, etc.

2) The best scientists are careful about making philosophical leaps that could undermine the notion of science. Newton, for example, was criticized by some for postulating "occult forces," that is, gravity. How did this invisible, mysterious force hold the earth in its orbit around the sun, pull cannon balls back to the earth, etc? Newton answered, "I make no hypotheses." He simply described what might be called formal causes of the motion of planets, etc, for example, force = mass X acceleration.

Einstein later provided additional causal explanation for moving objects. Space itself is curved by matter and thus we can picture a planet moving in a straight line in curved space, for example, around the rim of the gravity well created by the mass of the sun.

3) It is important for Objectivists not to let our philosophical understandings blind us to scientific discoveries or promising paths of examination. For example, if Bohr and Heisenberg were Objectivists would they have said "No, this stuff can't be right" and not have made the discoveries that they did?

The distinction made on this thread between science and philosophy is a good one. A scientist describes the probabilistic behavior of subatomic particles, the wave-particle duality of light, etc. The philosopher, always consistent with such discoveries, describes the nature of causality and existence. The good philosopher recognizes that just as scientific knowledge is discovered and refined over centuries, so our philosophical understanding of causality and existence can become richer and more refined. And scientists must recognize that if they make unwarranted philosophical leaps, for example, maintaining that quantum physics negates causality, then they are undermining all knowledge, including their own.

(Edited by Ed Hudgins on 4/27, 8:04am)

Post 71

Thursday, April 27, 2006 - 11:23am

I wanted to present the following two views as an indication of the state of the philosophy of quantum mechanics as seen by three physicists.
I found this one-page essay in Nature, Vol 438, p 743 (December, 2005) by Anton Zeilinger, one of the chief experimenters involved in recent quantum experiments. I think it encapsulates the opinion of many practicing physicists. He says:

The discovery that individual events are irreducibly random is probably one of the most significant findings of the twentieth century. ... For the individual event in quantum physics, not only do we not know the cause, there is no cause. The instant when a radioactive atom decays, or the path taken by a photon behind a half-silvered beam-splitter are objectively random. There is nothing in the Universe that determines the way an individual event will happen. Since individual events may very well have macroscopic consequences, including a specific mutation in our genetic code, the universe is fundamentally unpredictable and open, not causally closed.

Concerning the notion of complementarity, he says:

It is not just that we are unable to measure two complementary quantities of a particle, such as its position and momentum, at the same time. Rather, the assumption that a particle possesses both position and momentum, before the measurement is made, is wrong. Our choice of measurement apparatus decides which of these quantities can be reality in the experiment.

I just want to contrast this view with one that appeared in Physics Today in a two-page opinion piece in March, 2000, by two well-respected physicists, Chris Fuchs and Asher Peres. The title of their piece is "Quantum Theory Needs No 'Interpretation'". In it they say:

We set up this or that experiment to see how Nature reacts. We have learned something new when we can distill from the accumulated data a compact description of all that was seen and an indication of which further experiments will corroborate that description. This is what science is about. If, from such a description, we can further distill a model of a free-standing "reality" independent of our interventions, then so much the better. ... However, there is no logical necessity for a realistic worldview to always be obtainable. If the world is such that we can never identify a reality independent of our experimental activity, then we must be prepared for that, too. [Emphasis in original.]

And:

Contrary to those desires [tyring to fulfill a classical worldview], quantum theory does not describe physical reality. What it does is provide an algorithm for computing probabilities for the macroscopic events ("detector clicks") that are the consequences of our experimental interventions. [Emphasis in original.]

Thanks,
Glenn

Post 72

Thursday, April 27, 2006 - 12:11pm

But the wierdness goes far beyond the mere task of computing probabilities for macroscopic events.

Check this out:

"Most experiments do in fact involve intrusive measurements. For example, blocking one path or the other or moving detectors close to the slits obviously disturbs the photons passage in the two-slit experiment as does placing a detector along one route of the delayed-choice experiment. But an experiment done last year by Mandel's team at the University of Rochester shows that a photon can be forced to switch from wavelike to particlelike behaviour by something much more subtle than direct intervention.
The experiment relies on a parametric down-converter an unusual lens that splits a photon of a given energy into two photons whose energy is half as great. Although the device was developed in the 1960s, the Rochester group pioneered its use in tests of quantum mechanics. In the experiment, a laser fires light at a beam splitter. Reflected photons are directed to one down - converter, and transmitted photons go to another down-converter. Each down-converter splits any photon impinging on it into two lower-frequency photons one called the signal and the other called the idler. The two down-converters are arranged so that the two idler beams merge into a single beam. Mirrors steer the overlapping idlers to one detector and the two signal beams to a separate detector.

This design does not permit an observer to tell which way any single photon went after encountering the beam splitter. Each photon therefore goes both right and left at the beam splitter, like a wave, and passes through both down-converters, producing two signal wavelets and two idler wavelets. The signal wavelets generate an interference pattern at their detector. The pattern is revealed by gradually lengthening the distance that signals from one down - converter must go to reach the detector. The rate of detection then rises and falls as the crests and troughs of the interference wavelets shift in relation to each other, go in and out of phase.

Now comes the odd part. The signal photons and the idler photons, once emitted by the down-converters, never again cross paths; they proceed to their respective detectors independently of each other. Nevertheless, simply by blocking the path of one set of idler photons, the researchers destroy the interference pattern of the signal photons. What has changed?
The answer is that the observer's potential knowledge has changed. He can now determine which route the signal photons took to their detector by comparing their arrival times with those of the remaining, unblocked idlers. The original photon can no longer go both ways at the beam splitter, like a wave, but must either bounce off or pass through like a particle.

The comparison of arrival times need not actually be performed to destroy the interference pattern. The mere "threat" of obtaining information about which way the photon travelled, Mandel explains, forces it to travel only one route. "The quantum state reflects not only what we know about the system but what is in principle knowable," Mandel says.

Can the threat of obtaining incriminating information, once made, be retracted? In other words, are measurements reversible? Many theorists, including Bohr, thought not, and the phrase "collapse of the wave function" reflects that belief. But since 1983 Marlan O. Scully, [Isn't that just the correct name?-LB] a theorist at the University of New Mexico, has argued that it should be possible to gain information about the state of a quantum phoenomenon, thereby destroying its wavelike properties, and then restore those properties by "erasing" the information. "

Then....

"Erasing information about the path of a photon restores wavelike behaviour in an experiment done at the University of California at Berkeley. Pairs of identically polarized photons produced by a down-converter bounce off mirrors, converge again at a beam splitter and pass into two detectors. A coincidence counter observes an interference pattern in the rate of simultaneous detections by the two detectors, indicating that each photon has gone both ways at the beam splitter, like a wave. Adding a polarization shifter to one path destroys the pattern by making it possible to distinguish the photons. But placing two polarizing filters in front of the detectors makes the photons identical again, erasing the polarization distinction and restoring the interference pattern. "

Bob

Post 73

Thursday, April 27, 2006 - 1:19pm

Ed: I enjoyed reading your post. The last sentence though is a sticky one.

"And scientists must recognize that if they make unwarranted philosophical leaps, for example, maintaining that quantum physics negates causality, then they are undermining all knowledge, including their own."

Again, it seems we're down to defining causality.

Way back in 1928 A.S Eddington wrote:

Strict causality is abandoned in the material world. Our ideas of the controlling laws are in the process of reconstruction and it is not possible to predict what kind of form they will ultimately take; but all the indications are that strict causality has dropped out permanently. (Nature 332)

Although we don't seem to have a final answer yet, this seems even more true today.

Bob

Post 74

Thursday, April 27, 2006 - 2:07pm

Here's what I think is a great quote from the Stanford Encyclopedia of Philosophy. Causality is not directly mentioned, but it so very well sums up my general position nonetheless. Damn! I wish I could express myself as clearly!

In physics, the move of deepening our insight into the physical world by relativizing notions previously used as absolute has been applied repeatedly and very successfully. Here are a few examples. The notion of the velocity of an object has been recognized as meaningless, unless it is indexed with a reference body with respect to which the object is moving. With special relativity, simultaneity of two distant events has been recognized as meaningless, unless referred to a specific state of motion of something. (This something is usually denoted as "the observer" without, of course, any implication that the observer is human or has any other peculiar property besides having a state of motion. Similarly, the "observer system" O in quantum mechanics need not to be human or have any other property beside the possibility of interacting with the "observed" system S.) With general relativity, the position in space and time of an object has been recognized as meaningless, unless it is referred to the gravitational field, or to some other dynamical physical entity. The move proposed by the relational interpretations of quantum mechanics has strong analogies with these, but is, in a sense, a longer jump, since all physical events and the entirety of the contingent properties of any physical system are taken to be meaningful only as relative to a second physical system. The claim of the relational interpretations is that this is not an arbitrary move. Rather, it is a conclusion which is difficult to escape, following from the observation �� explained above in the example of the "second observer" �� that a variable (of a system S) can have a well determined value q for one observer (O) and at the same time fail to have a determined value for another observer (O��).

This way of thinking the world has certainly heavy philosophical implications. The claim of the relational interpretations is that it is nature itself that is forcing us to this way of thinking. If we want to understand nature, our task is not to frame nature into our philosophical prejudices, but rather to learn how to adjust our philosophical prejudices to what we learn from nature.

Notice the very careful choice of words here

"Similarly, the "observer system" O in quantum mechanics need not to be human or have any other property beside the possibility of interacting with the "observed" system S."

I find it tremendously fascinating the mere possibility of interaction changes reality, and that this has actually been seen in the lab no less!

Bob

Post 75

Thursday, April 27, 2006 - 4:27pm

Similarly, the "observer system" O in quantum mechanics need not to be human or have any other property beside the possibility of interacting with the "observed" system S."

I find it tremendously fascinating the mere possibility of interaction changes reality, and that this has actually been seen in the lab no less!

The statement B is not a logical conclusion of statement A. Further, to then claim this false statement to have "been seen in the lab no less" is itself a false conclusion not substantiated by examples.

Post 76

Thursday, April 27, 2006 - 5:10pm

Robert:

The statement B is not a logical conclusion of statement A.

Yes, you're absolutely correct, I agree, but I wasn't claiming that the statement logically followed from the other.

Further, to then claim this false statement to have "been seen in the lab no less" is itself a false conclusion not substantiated by examples.

This is not correct though. The actual basis for my second statement was contained in the experiment I described in post 72.

Bob

(Edited by Mr Bob Mac on 4/27, 5:16pm)

Post 77

Thursday, April 27, 2006 - 6:14pm

I wrote "But it is that very principle of induction that is incompatible with metaphysical randomness." Bob replied,

Induction is useful, but inherently flawed and unreliable especially when hidden variables exist. Inductive rules never been successfully formalised. Wishing it, or stating it doesn't make it true.

Induction is reasoning from the particular to the general. All scientific laws are based on it, including whatever theories enable us to predict the behavior of sub-atomic particles, even if those predictions are probabilistic. In the absence of induction, even predictions based on probabilities would be impossible, because one couldn't reason from the behavior of things in the present to the probability of similar behavior in the future. Nevertheless, Bob presents the following counter-example to the validity of induction:

"A favorite example used by critics of the Method of Agreement is the case of the Scientific Drinker, who was extremely fond of liquor and got drunk every night of the week. He was ruining his health, and his few remaining friends pleaded with him to stop. Realizing himself that he could not go on, he resolved to conduct a careful experiment to discover the exact cause of his frequent inebriations. For five nights in a row he collected instances of a given phenomenon, the antecedent circumstances being respectively scotch and soda, bourbon and soda, brandy and soda, rum and soda, and gin and soda [ugh!]. Then using the Method of Agreement he swore a solemn oath never to touch soda again!"

This example does not invalidate induction, any more than an error in reasoning invalidates deduction, as a legitimate method of inference. What it does illustrate is that induction can, if not carefully conducted, yield incorrect or misleading conclusions. How do you know that it was not the soda but the alcohol that was ruining the man's health? Only by a process induction, the very process that the above example claims to invalidate.

I quoted H.W.B. Joseph: "As long therefore as it is a, and stands related under conditions c to a subject that is s, no other effect than x can be produced; and to say that the same thing acting on the same thing under the same conditions may yet produce a different effect, is to say that a thing need not be what it is. But this is in flat conflict with the Law of Identity." Bob replied,

The law of identity tells us nothing and proves nothing, the line of reasoning is non-existent.

Bob, I don't think it's an exaggeration to say that you're not addressing my arguments. You said virtually the same thing in your last post, in which you wrote:

This is not a line of reasoning. This is simply an assertion that is not supported by evidence.

I replied, "Well, it's the conclusion of a fairly extensive line of reasoning, if you were to read the rest of my post, so I wouldn't call it "simply an assertion." You can't separate a conclusion from its reasons and then claim that it doesn't constitute a line of reasoning. That's a little disingenuous, don't you think?! In any case, my supporting "evidence" is philosophical. If you're going to take issue with my conclusion, then you ought at the very least to address my reasons for it. Would you say that it's simply an assertion to invoke the law of non-contradiction in arguing that a theory lacks logical consistency? If not, then why is it simply an assertion to invoke the law of identity in defense of the view that like causes imply like effects?"

And still, you refuse to address the argument, preferring instead simply to repeat your previous assertion. It's now very clear to me that you are not interested in a serious discussion, and that it is pointless for me to continue debating you. So this will be my last response to you on this issue. I was hoping it wouldn't come to this, but there has to be a good faith effort made by both parties in a dispute of this kind if any progress is to be made.

- Bill

Post 78

Thursday, April 27, 2006 - 11:16pm

Bill,

You are -- far and away -- more correct than not. But a subtle correction (of your posting) is, still, in order ...

==================
Induction is reasoning from the particular to the general.
==================

Induction is always from the particular -- but not always TO the general. In examining induction vs. deduction -- it is always the relation to the "particular" that counts; but this is not so, as to the relation to the "general." Induction always proceeds FROM the particular. And deduction always proceeds TO the particular. But one may induce TO the particular; and one may deduce FROM the particular. Examples available upon request.

Ed

(Edited by Ed Thompson on 4/27, 11:17pm)

Post 79

Friday, April 28, 2006 - 8:37am