Induction and Inertia

[Darrell Hougen]

I don't really have time to do this topic justice. However, in the context of the ongoing discussions of induction, I think it is appropriate to introduce a new concept into the debate.

The real achievement of Newton, which has been overshadowed by the development of the Lorenz-Einstein transformation equations, was not his description of motion (using the Galilean transformation equations) but his concept of inertia.

Newton was the first to formalize a concept which is, in some sense, intuitively obvious, yet simultaneously unprovable and irrefutable: things don't change unless something causes them to change and the degree of change is proportional to the strength of the cause.

In the specific context of physics, Newton discovered that a body in motion tends to stay in motion and that the amount by which its motion changes is proportional to the force applied. F = dp/dt. Force equals the rate of change of momentum. This law is valid, unaltered, under the theory of relativity. It has never been challenged.

The broader point is that this concept of inertia (identity) and the relationship between force (cause) and inertia (identity) is fundamental to our understanding of the world. It can be thought of as part of the Law of Identity or the Law of Causality (the Law of Identity applied to events). It is not obviously stated as part of Objectivism. Yet, it is a self evident fact that can neither be proven nor refuted. The exact relationship between force and momentum can be measured in the laboratory, but the fact that such a relationship exists and cannot be altered cannot be measured.

Now, how is this related to the current discussion about induction? Well, if the Law of Causality is taken to include the notion that the amount of change is related to the strength of the cause, then many of the problems of induction go away. One type of plant cannot produce another type of fruit unless something causes it to do so. The sun cannot fail to come up unless some celestial body wrecks the solar system. The world did not come into existence five years ago. In short, knowledge is possible if causality is properly understood. The example of white and black swans is silly and irrelevant.

Darrell

[Ellen Stuttle]

The broader point is that this concept of inertia (identity) and the relationship between force (cause) and inertia (identity) is fundamental to our understanding of the world. It can be thought of as part of the Law of Identity or the Law of Causality (the Law of Identity applied to events). It is not obviously stated as part of Objectivism.

I wouldn't expect it to be stated as part of Objectivism, since if it's true, the Objectivist theory of volition hasn't a leg to kick.

Now, how is this related to the current discussion about induction? Well, if the Law of Causality is taken to include the notion that the amount of change is related to the strength of the cause, then many of the problems of induction go away.

No, they don't. For one thing, the Newtonian principle as you've rephrased it is so vague it could cover multiple sins of theorizing. And even with the Newtonian principle you're faced with the logical impossibility of verifying it as universally true. Physics proceeds on the presupposition that it is true; nothing thus far has falsified it (and would evidence of falsification, should such be found, even be accepted, since the principle is so foundational to modern physics?). But it can't be conclusively confirmed.

Ellen

___

[BaalChatzaf]

In the specific context of physics, Newton discovered that a body in motion tends to stay in motion and that the amount by which its motion changes is proportional to the force applied. F = dp/dt. Force equals the rate of change of momentum. This law is valid, unaltered, under the theory of relativity. It has never been challenged.

Yes and No. In special relativity momentum measure in a frame of reference is:

m_rest * v/sqrt(1 - v*v/c*c) where v is the velocity of the body wrt to the frame of reference used.

If you read -Special Relativity- by A.P. French pp 212-216 you will see that force does not transform according to the Lorentz transform as does energy and momentum. Not only that the y and z components of a force do NOT align with the acceleration vector (it is trivial to prove, but it came as a surprise to me when I first saw it). This means that force is not the central mechanical concept in relativistic mechanics. Energy and momentum are because they transform correctly. In addition, force at a distance has no meaning in SR since simultaneity is not absolute.

So the equation F = dp/dt is correct, but the concept is not useful in relativistic mechanics. Fortunately force can be restated in terms of energy and momentum in both classical and relativistic mechanics which means it can be removed from discourse. What counts is the Lagrangian. All of the conservation laws are derivable by the symmetries of the Lagrangian by Noether's theorem.

The gut of mathematical physics is NOT cause. It is symmetry, especially of Lagrangians. All of the field laws can be derived from this. See Noether's theorem.

Ba'al Chatzaf

Edited September 27, 2007 by BaalChatzaf

[tjohnson]

The gut of mathematical physics is NOT cause. It is symmetry, especially of Lagrangians. All of the field laws can be derived from this. See Noether's theorem.

Ba'al Chatzaf

Other considerations about 'cause and effect'.

The notion of causality has been greatly modified by the substitution of space-time

for space and time. . . . Thus geometry and causation becomes inextricably

intertwined. (457) BERTRAND RUSSELL

and

The reader should not take what is said here as a denial that in this external

world some regularities of sequence occur; but the above analysis, which is mainly

due to Russell, shows clearly that the verbal principle of ‘same cause, same effect’

is structurally untenable. We can never manage to observe the ‘same cause’ in

detail. As soon as the antecedents have been sufficiently ascertained, so as to

calculate the consequences with some plausible accuracy as to details, the relations

of these antecedents have become so complex that there is very little probability that

they will ever occur again.

[John Dailey]

~ Maybe, just m-a-y-b-e, 'momentum' itself has to be (re?) defined...contextually of course? (Let's check Wiki!)

Darryl:

~ You think that what's considered as 'The Problem of Induction' is taken care of by your argument. I must agree with others: not so, per se. Everyone (well, most here, anyways) sees the prob not in terms of dynamics (as in your Newton example) where things empirically occur, but basically in terms of statics ('swans', 'white'; you know, THAT simplistic generalizing...'argument') where a property is phenomenally associated to (aka: 'generalized' as being inherently-part-of) an otherwise-defined entity. Gotta get past the statics-arguments before ya bring in the dynamics stuff; else, you're spittin' in the wind. Hume said 'X'; Mill said 'Y.'

~ Akin to the ASD, some side with one; others, the other. The acceptance of one argument/side determines the view of the other.

LLAP

J:D

[John Dailey]

Baal:

~ Thanx for the assertions. We'll all check out Noether's Theorem and debate it.

~ Can you give an argument about anything without using someone else's to support *your* point?

GS:

~ BR's comments on 'causality' are a bit trivially academic (if not 'tautological'[!]), since he clearly agreed with Hume's view, ('sunrise' tomorrow), no?

~ The thread's about 'induction' (as in real-world), not 'mathematical physics', the latter's gut or its GUT's symmetry or lack-thereof nwst.

Ellen:

~ What has 'volition' got to do with this?

~ Re anything being 'universally true' or 'conclusively confirmed', if Humean perception-empiricalness is the only basis which one accepts working from...such is definitionally true of everything one believes (see B. Russell for support on this.) --- Akin to the ASD arg, 'East is East, and...' here.

LLAP

J:D

Edited October 1, 2007 by John Dailey

[BaalChatzaf]

Baal:

~ Thanx for the assertions. We'll all check out Noether's Theorem and debate it.

~ Can you give an argument about anything without using someone else's to support *your* point?

Neother's theorem is not a subject of debate. It is a mathematical theorem that was proved 80 years ago by Amille (Emy) Noether, Max Noether's daughter. It establishes a correspondence between the symmetries of a Langranian Action Functional and conserved (physical) quantities. One does not debate Neother's theorem anymore than one debates Pythagoras' Theorem. One can -discuss- Noether's Theorem however. It's correctness is a matter of historical fact.

Here is a reference to help get you started to understand this rather remarkable theorem:

http://www.math.ucr.edu/home/baez/noether.html

Almost all of Baez Weekly notes are gems. If you are interested in the intersection between mathematics and physics they are the items to read. He presents his stuff at two levels: gentle (for non physicists) and more advanced (for those with the background).

Ba'al Chatzaf

[Darrell Hougen]

The broader point is that this concept of inertia (identity) and the relationship between force (cause) and inertia (identity) is fundamental to our understanding of the world. It can be thought of as part of the Law of Identity or the Law of Causality (the Law of Identity applied to events). It is not obviously stated as part of Objectivism.

I wouldn't expect it to be stated as part of Objectivism, since if it's true, the Objectivist theory of volition hasn't a leg to kick.

Now, how is this related to the current discussion about induction? Well, if the Law of Causality is taken to include the notion that the amount of change is related to the strength of the cause, then many of the problems of induction go away.

No, they don't. For one thing, the Newtonian principle as you've rephrased it is so vague it could cover multiple sins of theorizing. And even with the Newtonian principle you're faced with the logical impossibility of verifying it as universally true. Physics proceeds on the presupposition that it is true; nothing thus far has falsified it (and would evidence of falsification, should such be found, even be accepted, since the principle is so foundational to modern physics?). But it can't be conclusively confirmed.

Let me try this again, since I wasn't very clear the first time. From a purely Objectivist point of view, everything acts according to its nature (identity). To deny that is to deny that things have an identity. Furthermore, a thing cannot change its identity instantly. To argue that it could, would be to deny that it had any identity in the first place.

The principle of inertia states (broadly) that entities tend to maintain their identity unless acted upon by an outside agent. Moreover, there is a limit to the rate at which the agent can change the original thing depending upon the power of the agent and the inertia of the entity.

Perhaps this doesn't really justify induction in the sense of Hume. But, it does justify the viewpoint that predictions can be made about the behavior of various entities based on only a few observations. The key is understanding the fundamental (or essential) aspects of the entity. It may be that only one (detailed) observation is enough to predict the entity's behavior. The notions of conjecture and refutation seem out of place here. If the thing is understood, predictions can be made. If it is not, then they cannot.

With regards to free will, one has to accept the fact that some entities are capable of spontaneous action. That is part of their nature (identity). The principle of inertia must therefore be expanded to allow for the presence of an internal power contributing to the rate at which something can change. But that rate is still limited by the amount of internal "power" of the entity in question.

Darrell

P.S. Sorry for the slow reply, but I forgot to click "post."

Edited October 1, 2007 by Darrell Hougen

[BaalChatzaf]

The principle of inertia states (broadly) that things tend to maintain their identity unless acted upon by an outside agent. Moreover, there is a limit to the rate at which the agent can change the original thing depending upon the power of the agent.

The principle of inertia is stated in Newton's First Law. A body will move uniformly (at a fixed velocity) in a straight line when zero net force acts on it. Newton's second law says that the change in the motion (i.e. momentum) of a body is proportional to the force acting on it in the direction of the force.

I do not see the word Identity anywhere here. You are reading it in. If a green apple is acted on by a force, it will remain green. If it is not acted on by a force it will remain green. If it is acted on by a lot of force it will become green applesauce.

There is no way you twist Newtonian physics to make it look like Objectivist Philosophy. Nor would you want to. Newtonian Physics, while very useful, happens to be wrong. It is Galilean Invariant and the world is (locally) Lorentz Invariant.

Now here is one for you. An electron and a positron go into a bar and meet. What becomes of their identities?

Ba'al Chatzaf

Edited October 1, 2007 by BaalChatzaf

[Dragonfly]

The principle of inertia states (broadly) that entities tend to maintain their identity unless acted upon by an outside agent.

What is the outside agent that makes a radioactive atom decay into a different atom?

[BaalChatzaf]

The principle of inertia states (broadly) that entities tend to maintain their identity unless acted upon by an outside agent.

What is the outside agent that makes a radioactive atom decay into a different atom?

Aristotle might say that atom is striving to get to its proper state. It was violent motion that produced such atoms (the explosions of large stars) so left to its own devices the atom wants to become what it was.

Sorry. I just could not resist.

Ba'al Chatzaf

[Darrell Hougen]

The principle of inertia states (broadly) that things tend to maintain their identity unless acted upon by an outside agent. Moreover, there is a limit to the rate at which the agent can change the original thing depending upon the power of the agent.

The principle of inertia is stated in Newton's First Law. A body will move uniformly (at a fixed velocity) in a straight line when zero net force acts on it. Newton's second law says that the change in the motion (i.e. momentum) of a body is proportional to the force acting on it in the direction of the force.

I do not see the word Identity anywhere here. You are reading it in. If a green apple is acted on by a force, it will remain green. If it is not acted on by a force it will remain green. If it is acted on by a lot of force it will become green applesauce.

There is no way you twist Newtonian physics to make it look like Objectivist Philosophy. Nor would you want to. Newtonian Physics, while very useful, happens to be wrong. It is Galilean Invariant and the world is (locally) Lorentz Invariant.

I realize that I am taking liberties with the term "inertia." The point is that there is a limit to the rate at which the state of an object can change and that we can know that rate. In physics, we can know that limit by measuring the mass of an object. That is, the rate of change in motion is related to the force applied by the (relativistic) mass. But, all systems are ultimately physical, so it makes sense to coin a term that captures the notion that the rate at which something can change is limited and that we can know that limit by understanding the entity in question and the nature of the forces that act upon it.

To say that Newtonian physics is wrong is to exaggerate the situation. There are very important and profound respects in which it is right, the fact that F = dp/dt being one of them. The philosophical point that there is a definite relationship between force and momentum being another, related aspect.

Now here is one for you. An electron and a positron go into a bar and meet. What becomes of their identities?

They are obliterated. Actually, momentum is still conserved. But, the relevant aspect of the example is that electrons and positrons are very small --- they have very little mass --- and therefore, very little resistance to change. They have very little inertia and are therefore capable of undergoing dramatic changes very quickly.

Darrell

[Darrell Hougen]

The principle of inertia states (broadly) that entities tend to maintain their identity unless acted upon by an outside agent.

What is the outside agent that makes a radioactive atom decay into a different atom?

The principle of inertia must therefore be expanded to allow for the presence of an internal power contributing to the rate at which something can change. But that rate is still limited by the amount of internal "power" of the entity in question.

Darrell

[BaalChatzaf]

They are obliterated. Actually, momentum is still conserved. But, the relevant aspect of the example is that electrons and positrons are very small --- they have very little mass --- and therefore, very little resistance to change. They have very little inertia and are therefore capable of undergoing dramatic changes very quickly.

Darrell

Conserved! You said the Magic Word. Conserved. Conservation is not Identity in the sense that Rand meant it.

The gut of physics is not Identity in the Randian sense. It is symmetry and their related conservations.

Ba'al Chatzaf

[Michael Stuart Kelly]

Conserved! You said the Magic Word. Conserved. Conservation is not Identity in the sense that Rand meant it.

The gut of physics is not Identity in the Randian sense. It is symmetry and their related conservations.

(yawn)

Atlas Shrugged, Galt's speech, p. 931:

Matter is indestructible, it changes its forms, but it cannot cease to exist.

Gimme a break!

Michael

[BaalChatzaf]

Conserved! You said the Magic Word. Conserved. Conservation is not Identity in the sense that Rand meant it.

The gut of physics is not Identity in the Randian sense. It is symmetry and their related conservations.

(yawn)

Atlas Shrugged, Galt's speech, p. 931:

Matter is indestructible, it changes its forms, but it cannot cease to exist.

Gimme a break!

Michael

When an electron and a positron anihilate each other, the matter disappears and the energy appears in the form of photon. Two spin 1/2 Fermions have gone bye-bye and a spin 1 positron is there. It does not have a placard hung around its neck saying - Hi, I am a photon which resulted from the mutual anihilation of a an electron and a positron. That Matter is Gone. There may be a kind of equivalence between matter and energy (by way of Einstein's equation) but they are not freely and arbitrarily interchangable or interconvertable.

Some quantities are conserved however. Total charge in the universe is left unchanged. If you divide the energy of the photon by c (speed of light) squared you get a number equal to the rest mass of the electron plus the rest mass of the positron.

That fact that you cannot reverse infer the origin of the photon from the mutual anihilation of a pair of anti-particles indicates that identity is lost. What is lost are properties, which are what Identity is made of. The identity of an entity is the list of all of its properties (Leibniz Law) also stated by Frege.

I have just given you your break. So Yawn On.

Ba'al Chatzaf

[Darrell Hougen]

They are obliterated. Actually, momentum is still conserved. But, the relevant aspect of the example is that electrons and positrons are very small --- they have very little mass --- and therefore, very little resistance to change. They have very little inertia and are therefore capable of undergoing dramatic changes very quickly.

Conserved! You said the Magic Word. Conserved. Conservation is not Identity in the sense that Rand meant it.

The gut of physics is not Identity in the Randian sense. It is symmetry and their related conservations.

Yes. Identity can and does change. We all grow older. I am not exactly the same person I was 20 years ago or two minutes ago. However, I am more similar to the person I was two minutes ago than I am to the person I was 20 years ago. Change takes time. Things with more inertia change more slowly than things with less inertia. An electron can be annihilated in the blink of an eye. The sun could be destroyed by a collision with another star, but the process would probably take a long time. At the very least, it would be foreseeable many years in advance.

The fact that change takes time justifies claims such as: The sun will come up tomorrow. If we understand the nature of things such as the sun, we can make reasonable predictions about them.

Predicting the color of the next swan is not reasonable. Unless you live in a vacuum, you know that color is a superficial quality. Cattle, horses, dogs and cats all come in a variety of colors. So do many other things. So why would we expect the situation to be any different when it comes to swans?

If you take Hume or Popper literally, how could you know that quantities are conserved? How do you know that momentum is conserved? How do you know that energy is conserved? How do you know that charge is conserved? Just because they always were in the past? Is it possible that momentum, energy and charge are not conserved? And if a non-conservative system is not possible, how do you know it is not possible?

Darrell

Edited October 2, 2007 by Darrell Hougen

[Roger Bissell]

Conserved! You said the Magic Word. Conserved. Conservation is not Identity in the sense that Rand meant it.

The gut of physics is not Identity in the Randian sense. It is symmetry and their related conservations.

(yawn)

Atlas Shrugged, Galt's speech, p. 931:

Matter is indestructible, it changes its forms, but it cannot cease to exist.

Gimme a break!

Michael

When an electron and a positron anihilate each other, the matter disappears and the energy appears in the form of photon. Two spin 1/2 Fermions have gone bye-bye and a spin 1 positron is there. It does not have a placard hung around its neck saying - Hi, I am a photon which resulted from the mutual anihilation of a an electron and a positron. That Matter is Gone. There may be a kind of equivalence between matter and energy (by way of Einstein's equation) but they are not freely and arbitrarily interchangable or interconvertable.

Some quantities are conserved however. Total charge in the universe is left unchanged. If you divide the energy of the photon by c (speed of light) squared you get a number equal to the rest mass of the electron plus the rest mass of the positron.

That fact that you cannot reverse infer the origin of the photon from the mutual anihilation of a pair of anti-particles indicates that identity is lost. What is lost are properties, which are what Identity is made of. The identity of an entity is the list of all of its properties (Leibniz Law) also stated by Frege.

I have just given you your break. So Yawn On.

Ba'al Chatzaf

I don't understand the elevation in physics of Conservation above Identity, or the claim that Conservation in physics is not what Rand meant by Identity in metaphysics.

Isn't it understood by all present that the physical universe and the things in it ARE SUCH THAT the Conservation laws hold? I.e., because of the IDENTITY of the physical universe, the physical universe being the way that it is, the Conservation laws hold true? Is anyone possibly entertaining any other relation between Identity and Conservation -- e.g., that Conservation holds simply because it holds, and not because things are the way they are (Identity)?

If a photon originates from the mutual annihilation of a pair of anti-particles, then it is in the NATURE of anti-particles and their interaction that a photon is produced. The precise details of how and why a photon (rather than something else, or even nothing else) is the result may never be known, or it may be discovered tomorrow. But it is a FACT of the IDENTITY of certain things in reality that this is what happens.

REB

P.S. -- I have another puzzlement about modern philosophy, modern physics, and identity, in relation to Objectivist skepticism over quantum physics, but I'll save it for a separate post.

[Michael Stuart Kelly]

Roger,

Ain't it a shame to have to play master of the obvious?

Disagreement, OK. But sometimes it gets a bit too dumb for such intelligent people.

Dayaamm!

Michael

[Roger Bissell]

Roger,

Ain't it a shame to have to play master of the obvious?

Disagreement, OK. But sometimes it gets a bit too dumb for such intelligent people.

Dayaamm!

Michael

Please clarify. Are you suggesting that there is willful dumbness or willful "dumbness" going on here? :-)

REB

[Michael Stuart Kelly]

Roger,

I don't know if it is willful or not, but it sure is dumb. Please see here.

Let's say that I hope it is willful. If it is not willful, that would mean that... hmmm... nah...

Michael

[tjohnson]

In my opinion the answer to this question is briefly, this:—As far as the laws of

mathematics refer to reality, they are not certain; and as far as they are certain, they

do not refer to reality. (151) A. EINSTEIN

Please read this carefully. It means that when take mathematics and APPLY it to "reality" it does not work perfectly (not certain). In other words there is alway a little room for error. Any "law" of physics can only ever be approximately "true", including conservation laws, etc. We need to think about "laws of physics" as only general relationships - not absolute relationships as they are in pure mathematics.

Edited October 2, 2007 by general semanticist

[Ellen Stuttle]

[....]

The principle of inertia states (broadly) that entities tend to maintain their identity unless acted upon by an outside agent. Moreover, there is a limit to the rate at which the agent can change the original thing depending upon the power of the agent and the inertia of the entity.

Perhaps this doesn't really justify induction in the sense of Hume. But, it does justify the viewpoint that predictions can be made about the behavior of various entities based on only a few observations. The key is understanding the fundamental (or essential) aspects of the entity. It may be that only one (detailed) observation is enough to predict the entity's behavior. The notions of conjecture and refutation seem out of place here. If the thing is understood, predictions can be made. If it is not, then they cannot. (my highlight)

With regards to free will, one has to accept the fact that some entities are capable of spontaneous action. That is part of their nature (identity). The principle of inertia must therefore be expanded to allow for the presence of an internal power contributing to the rate at which something can change. But that rate is still limited by the amount of internal "power" of the entity in question.

[....]

The fact that change takes time justifies claims such as: The sun will come up tomorrow. If we understand the nature of things such as the sun, we can make reasonable predictions about them. (my highlight)

Predicting the color of the next swan is not reasonable. Unless you live in a vacuum, you know that color is a superficial quality. Cattle, horses, dogs and cats all come in a variety of colors. So do many other things. So why would we expect the situation to be any different when it comes to swans?

If you take Hume or Popper literally, how could you know that quantities are conserved? How do you know that momentum is conserved? How do you know that energy is conserved? How do you know that charge is conserved? Just because they always were in the past? Is it possible that momentum, energy and charge are not conserved? And if a non-conservative system is not possible, how do you know it is not possible?

Ah, now I see what you're getting at. Regarding how we know the conservation laws always hold, the same old problem remains: We DON'T know. We'd need just one enormous amount of falsification to throw them out -- even assuming we found falsification, we'd interpret it as an anomoly because of how foundational these laws are to the whole theoretical edifice of modern physics. I'd say that these laws -- although they have a great deal of observational support -- are more in the nature of postulates which are accepted as required assumptions.

The other laws on the basis of which we make predictions are more clearly arrived at by a process of conjecture and refutation and could more easily be challenged. That we have lots of reason to believe that they hold, and thus to be confident in predictions, still doesn't say that we know they hold.

Thus I think the answer to why conjectures and refutations are still in place here is to emphasize the IF in the passages I've highlighted:

" [....] IF the thing is understood, predictions can be made. IF it is not, then they cannot."

"IF we understand the nature of things such as the sun, we can make reasonable predictions about them."

We aren't ever entirely sure that our understanding is accurate. (Which doesn't mean we have any reason to lose sleep worrying over the accuracy of our belief in the next day's sunrise.)

Regarding the issue of volition, that's one I'm still puzzling over, albeit from a strongly different angle of approach than the Objectivist theory. I'm glad you understood the point I was making. I've found few Objectivists who do understand it -- maybe because so few Objectivists have much background in physics.

Ellen

___

Edited October 2, 2007 by Ellen Stuttle

[Guyau]

Hi Darrell,

It is more accurate to say that Descartes discovered the principle of inertia, rather than Newton. Galileo got it first, but not quite. On this see page 29 of my "Induction on Identity" in Objectivity V1N3.

On the development of mechanics from Descartes to Huygens to Newton, see the first two Parts of my "Space, Rotation, Relativity" in Objectivity V2N2 and V2N3.

On the transformation, by Planck (1906-7), of the definition of Newtonian force and Newton's second law, so as to make the latter invariant under Lorentz transformations across inertial frames, see pages 169-70 of Part 4 of "Space, Rotation, Relativity" in Objectivity V2N6.

Here is the Subject Index entry for Dynamics for Objectivity:

Dynamics

Chaotic V1N3 25, V1N5 72–73, 75, V2N1 31–45;

Classical V1N3 28–29, 39–40, 106–8, V1N4 71–73, V1N5 14, 75, 144, V2N1 32–40, V2N2 26–28, 117, 120, V2N3 52–57, 59–60, 71, V2N4 185-86, V2N5 4, V2N6 132–34, 142–43, 146, 165–66, 170;

Conserved Quantities in V1N3 35, 39–40, V1N4 73, V2N2 23, 26, 125, V2N3 56, V2N6 133, 136–37, 164–65, 169, 171, 175;

Electromagnetic V1N5 13–14, V2N6 136–49, 152–53, 164–68, 177–78, 181;

Flatly False V1N3 28–29, V2N2 24;

General-Relativity V1N3 39, V1N4 72, V1N5 14–15, V2N6 136, 150, 168;

Gravitational V1N3 14, 31, V1N5 13–15, V2N2 28, V2N3 69, V2N6 132, 142–43, 150, 174–75, 186;

Quantum V1N3 25, 39, V1N4 70, 74–79, V1N5 16, 76, 81, 84–90, V2N1 40–43, V2N2 120–26, V2N3 69;

Special-Relativity V1N4 72–73, V2N2 27, 122, V2N6 164–71

Edited October 2, 2007 by Stephen Boydstun

[Darrell Hougen]

Ah, now I see what you're getting at. Regarding how we know the conservation laws always hold, the same old problem remains: We DON'T know. We'd need just one enormous amount of falsification to throw them out -- even assuming we found falsification, we'd interpret it as an anomoly because of how foundational these laws are to the whole theoretical edifice of modern physics. I'd say that these laws -- although they have a great deal of observational support -- are more in the nature of postulates which are accepted as required assumptions.

...

Thus I think the answer to why conjectures and refutations are still in place here is to emphasize the IF in the passages I've highlighted:

" [....] IF the thing is understood, predictions can be made. IF it is not, then they cannot."

"IF we understand the nature of things such as the sun, we can make reasonable predictions about them."

We aren't ever entirely sure that our understanding is accurate. (Which doesn't mean we have any reason to lose sleep worrying over the accuracy of our belief in the next day's sunrise.)

But, this is exactly what we do need to worry about according to Hume and Popper. The problem is that if we can't be sure of anything, then we can't know if we're close either. We could be way off.

Looking at the example of swans, it could be that even though the first 100 swans you saw were white, thereafter every swan you saw might be black (assuming you didn't see the same swan again). Similarly, it could be the case that although momentum has always been conserved in every experiment ever performed that conservation of momentum is an anomaly and that momentum is usually not conserved. Perhaps most events involve large violations of momentum conservation.

I'm not sure I know how to coherently argue against the Humean position, but there are some things to consider. The general notion of inertia is one. Another possible counter argument is that there is a limit to the current complexity of things in the universe. If that is the case, then, if we gather enough information about entities in the universe we are actually capable of understanding them. They can't do weird and bizarre things because there are no hidden attributes capable of making them do those things. Yes, we keep discovering new things, such as neutrinos, for example, but look at how weakly neutrinos interact with ordinary matter. The discovery of the neutrino doesn't amount to any sort of admission that we were missing something of enormous importance.

The Humean argument amounts to an argument that everything is infinite. It is an argument that there is an infinite number of swans so that seeing some number of them doesn't tell you anything about swans. There is an infinite number of physical principles of unlimited significance so that knowing some number of them doesn't tell you anything about what will happen to the sun tomorrow.

The Humean position (and the position of Popper) begs arbitrariness. He doesn't claim that arbitrary things (such as God) exist, but he essentially says that you can't rule out any possibility, therefore, you can't really know anything about anything. Therefore, in Popper's words, everything is conjectural.

Regarding the issue of volition, that's one I'm still puzzling over, albeit from a strongly different angle of approach than the Objectivist theory. I'm glad you understood the point I was making. I've found few Objectivists who do understand it -- maybe because so few Objectivists have much background in physics.

Free will is a difficult issue that I don't really understand either. But, yes, there is a problem with Classical Physics re free will.

Darrell