Shut Up and Calculate: Exploring Feynman's Ideas on Physics

[apeiron]

Speaking of entropy and its direction, I am curious how strong a certainty are you willing to express(in percents) that anything is actually moving? As in the statement - "physical motion is possible and actual"?

100 per cent. Otherwise what is inertia all about? Of course, motion needs to be measured against some background, so there is the contextual or relativistic issue.

 

[GeorgCantor]

100 per cent.

Hmmm, 100% certainty isn't typical of philosophers and i haven't noticed 100% certanty expressed on PF(except on the math sub-forum), so this must also be valid of physicists.

Otherwise what is inertia all about?

Good question. What is mass all about? What is space all about? Or matter? Or entropy?

Of course, motion needs to be measured against some background, so there is the contextual or relativistic issue.

Well not only. Motion is one of the fundamental physical concepts together with space, matter and time, so the conceptual problems with motion are at least as deep as those with the other 3.

You have the issue of continuous motion where infinity briefly touches on finiteness in a Zeno-like fashion(infinite converging series leading to finiteness). Then you have your physical theories of measurements(GR and QM) that explain motion as a series of measurements(no motion except that which is wrongfully? inferred after the measurements by your perception). Then you have Biology that explain motion as perception of frames per second(you always perceive a "Now" frame out of a series). Motion in qm is even wilder and quite possibly non-existent(sum over histories; seldomly anyone would argue on quantum trajectories). Then you have those involved in the foundational issues of QM sugesting that space and time must be emergent phenomena from the interaction of more basic entities. But the heart of the problem is the cesession of being of the said object at particular coordinates and its appearance at another that we infer to have been caused by 'motion'. A blockworld model, that is consistent with the evidence, is silent on these issues as they are way deeper than physics can currently deal with.

Anyway, i was merely interested where your strong confidence comes from on these unresolved foundational issues and the idea that flow of entropy is a necessary subtrate of all being.


Have a look at this 'motion' example with additional perception surprizes:

http://physicsofopticalillusions.yolasite.com/insane.php

 

[apeiron]

But the heart of the problem is the cesession of being of the said object at particular coordinates and its appearance at another that we infer to have been caused by 'motion'.

This is going off-topic and if you are interested, you could pose your question in its own thread (not that it matters much as this thread is already at a dead-end).

But briefly, my reply was about theoretical contexts in which motion is an irreducible property. And so - in terms of the model - 100 per cent certainty becomes possible.

What other models might say is another matter.

And the same applies for any claims about entropy gradients. The models cannot be doubted because we have constructed them from axioms.

Both motion and dissipation also seem to be facts about the reality as best we can observe. But there is always the possibility of new facts from more subtle measurements coming along.

Again, you want to focus on the fact that models always leave room for doubt (even when doubt seems to be unreasonable). I'm looking at the same situation from the other point of view. There is surprisingly little doubt now about some very fundamental seeming truths.

 

[brainstorm]

Could you say that motion is just a way of describing momentum changes in tandem with relative times and distances to other objects? Couldn't you simply say that objects with inertia change momentum and collide with each other (and interact with each other's fields) from time to time, without specifying their location vis-a-vis a coordinate system? I'm not claiming this would be particularly handy, but I feel the need to raise this kind of point whenever a discussion about the fundamental nature of motion, space, time, etc. comes up.

 

[apeiron]

Could you say that motion is just a way of describing momentum changes in tandem with relative times and distances to other objects?

Such a model would say nothing about relative distances and so nothing about the variable speeds of objects. It might be possible to make such a model, but a failure to represent motion would not throw doubt on motion would it?

But the heart of the problem is the cesession of being of the said object at particular coordinates and its appearance at another that we infer to have been caused by 'motion'.

Georg, the problem you seem to be raising is that motion is deemed to be a continuous action and yet our models presume that motions are constructed as a succession of discrete steps. This leads to familiar paradoxes.

As usual, I would point out that all metaphysical concepts are derived as dichotomies, and dichotomies are limit state descriptions. So the metaphysical model here is discrete~continuous. Or constructed motion vs constrained action. And we can model from either point of view.

We can construct a motion mechanically as a series of discrete steps (which is the classical Newtonian approach, points along a line). Or we can constrain an action to a least mean path (which would be the top-down QM sum over histories approach, a collapse of possibilities to a single crisp path).

Which is more real? Well the dichotomy tells us that neither the discrete nor the continuous is real. They are the limits of what can be achieved (and so are not themselves achievable). But we can get infinitesimally close.

 

[GeorgCantor]

Georg, the problem you seem to be raising is that motion is deemed to be a continuous action and yet our models presume that motions are constructed as a succession of discrete steps. This leads to familiar paradoxes.

As usual, I would point out that all metaphysical concepts are derived as dichotomies, and dichotomies are limit state descriptions. So the metaphysical model here is discrete~continuous. Or constructed motion vs constrained action. And we can model from either point of view.

We can construct a motion mechanically as a series of discrete steps (which is the classical Newtonian approach, points along a line). Or we can constrain an action to a least mean path (which would be the top-down QM sum over histories approach, a collapse of possibilities to a single crisp path).

Which is more real? Well the dichotomy tells us that neither the discrete nor the continuous is real. They are the limits of what can be achieved (and so are not themselves achievable). But we can get infinitesimally close.

Yes, good point. We at last agree on something truly fundamental - reality cannot be neither continuous nor discrete. That's actually why i raised the point with you about motion, since you seem to like dichotomies and models not being the world.

If this point - reality cannot be neither continuous nor discrete is fully appreciated by physicists and philosophers alike, the interconnectedness/nonseparability issue of quantum theory will begin to pale. It's just that the majority isn't ready for the manouver yet.

 

[brainstorm]

Such a model would say nothing about relative distances and so nothing about the variable speeds of objects. It might be possible to make such a model, but a failure to represent motion would not throw doubt on motion would it?

Only because the "model" utilized in everyday perception construes objects in terms of relative position. Everyday perception also construes the ground as stationary and flat, while the sun and moon are perceived as rising and falling along with the stars. I forget why this issue came up here in the first place, though.

 

[Pythagorean]

I think I prefer:

shut up and analyze mathematical statements in a qualitative way

 

[brainstorm]

I think I prefer:

shut up and analyze mathematical statements in a qualitative way

Yes, and please translate them into other languages too, e.g. English, so the math illiterate or semi-literate among us can understand more about science than we could otherwise.

 

[Pythagorean]

Yes, and please translate them into other languages too, e.g. English, so the math illiterate or semi-literate among us can understand more about science than we could otherwise.

A lot of my foreign friends claim that English is their preferred language for technical detail, because their native language just isn't descriptive enough. Though, they like to use their native language for emotional expression because it's more suited (maybe it's just a personal preferences though, since they were raised with that language, and thus developed emotionally around it).

I feel the same way about math vs. english. Math is a very descriptive language. When we translate it to English, concepts can be lost and misrepresented. Which is why, for instance, everyone still things Wave-Particle duality exists. The only reason we use wave in wave mechanics is because it utilizes a wave equation. This shouldn't be confused with ocean waves, for instance.

 

[brainstorm]

Which is why, for instance, everyone still things Wave-Particle duality exists. The only reason we use wave in wave mechanics is because it utilizes a wave equation. This shouldn't be confused with ocean waves, for instance.

So how do particles shift frequencies if they don't move in waves with wavelengths?

 

[SixNein]

A lot of my foreign friends claim that English is their preferred language for technical detail, because their native language just isn't descriptive enough. Though, they like to use their native language for emotional expression because it's more suited (maybe it's just a personal preferences though, since they were raised with that language, and thus developed emotionally around it).

I feel the same way about math vs. english. Math is a very descriptive language. When we translate it to English, concepts can be lost and misrepresented. Which is why, for instance, everyone still things Wave-Particle duality exists. The only reason we use wave in wave mechanics is because it utilizes a wave equation. This shouldn't be confused with ocean waves, for instance.

I feel much of the same about math vs physics. I sometimes wonder if physicists are not interpreting mathematical problems and descriptions as physical problems and descriptions.

 

[Pythagorean]

I feel much of the same about math vs physics. I sometimes wonder if physicists are not interpreting mathematical problems and descriptions as physical problems and descriptions.

Generally, physicists don't work on "mathematical problems". They use math in physical problems.

So how do particles shift frequencies if they don't move in waves with wavelengths?

quantum particles don't "move".

Ok... so an ocean wave is classically simulated as a bunch of hard little pellets that move continuously through space according to a wave equation. In other words, the motion of each particle is described by the superposition of several waveforms (i.e. multiple frequencies).

A single quantum particle's position, velocity, energy, etc are described by operations on the probability wave function. Completely different application, it just happens to use the same shape of equation.

please shut up and calculate, then come back and we'll have a philosophical discussion based on relevant arguments.

 

[brainstorm]

quantum particles don't "move".

Ok... so an ocean wave is classically simulated as a bunch of hard little pellets that move continuously through space according to a wave equation. In other words, the motion of each particle is described by the superposition of several waveforms (i.e. multiple frequencies).

A single quantum particle's position, velocity, energy, etc are described by operations on the probability wave function. Completely different application, it just happens to use the same shape of equation.

please shut up and calculate, then come back and we'll have a philosophical discussion based on relevant arguments.

How foolish does someone have to be to expend time and effort performing calculations for a model that they don't understand qualitatively? It would be like telling someone to make a sacrifice to the volcano to get a good harvest. Then when the person asks how or why it's supposed to work, you tell them "shut up and sacrifice and you'll see." It's utterly anti-scientific to approach research this way. Ironically there's a scene in Madagascar 2 where someone asks how a volcano sacrifice works and it is actually explained to the point of being critically accessible; which is more than can be said about people who think, "shut up and calculate."

 

[Pythagorean]

How foolish does someone have to be to expend time and effort performing calculations for a model that they don't understand qualitatively? It would be like telling someone to make a sacrifice to the volcano to get a good harvest. Then when the person asks how or why it's supposed to work, you tell them "shut up and sacrifice and you'll see." It's utterly anti-scientific to approach research this way. Ironically there's a scene in Madagascar 2 where someone asks how a volcano sacrifice works and it is actually explained to the point of being critically accessible; which is more than can be said about people who think, "shut up and calculate."

But that's a complete misrepresentation of how it works. It' s not like we sit around with calculators and just punch in numbers and get a result. That seems to be the mentality being projected here.

You work qualitatively with the equations in about 90% of the work you do pursuing a physics degree. It's highly stressed in the physics curriculum that you understand the concepts. We don't even use numbers or calculators in the advanced physics courses because it's all algebra and calculus analysis on the general equations themselves, as variables.

It's symbolic manipulation. Each variable has a real, significant meaning. They are logic statements that you can manipulate to find other logic statements. In fact, we're criticized by mathematicians when our concepts outweigh our mathematics. For instance, consider any inverse square law. What happens when the distance between two charged particles is 0? According to the law, the force between them is infinite... but this is impossible of course. Obviously, the equations don't match observation at that point, but that's fine. We're more interested in the qualitative behavior.

 

[humanino]

How foolish does someone have to be to expend time and effort performing calculations for a model that they don't understand qualitatively? It would be like telling someone to make a sacrifice to the volcano to get a good harvest. Then when the person asks how or why it's supposed to work, you tell them "shut up and sacrifice and you'll see." It's utterly anti-scientific to approach research this way. Ironically there's a scene in Madagascar 2 where someone asks how a volcano sacrifice works and it is actually explained to the point of being critically accessible; which is more than can be said about people who think, "shut up and calculate."

The only place I know of where one can experiment on a system for which we do not have mere quantum "corrections", but rather where the system is dominated by wild quantum relativistic fluctuations : hadrons.

It so happens that we pretty much have the exact theory describing those beasts : mostly QCD + electroweak corrections.

It turns out that there are pretty much as many hadronic models as there are people trying to model them : we know the relevant fundamental degrees of freedom (quarks and gluons) but we do not know how to calculate the observed properties of the effective degrees of freedom (mesons and baryons).

So an entire community has developed during the last 1.5 decade or so, doing non-perturbative calculations on the lattice. They hope to gather some insights on the effective models, compare their brute-force calculations with predictions which cannot be compared with experiments (either not yet or not in principles), offer guidance in the perturbative to non-perturbative transition.

Those are literally thousands of highly qualified computational scientists. You just dismissed their entire enterprise from a line you picked up in a cartoon ?

The level of the philosophy sub-forum never ceases to amaze me. It is just plain wrong to have a superficial and distant understanding of what people do (like 99% of the participants of this forum do with Bohr) yet display openly contempt and random judgement on a lifetime's work of Nobel prize winners.

 

[Pythagorean]

Humanino, maybe you can help me out with another example. I remember learning about a case where a physicist "jumped" from one equation to another using physical intuition.

It sent up red flags for some prominent mathematicians at the time, who immediately jumped into show formally why he (she?) was wrong... but after pages of tedious calculation, discovered that the expressions were in fact equivalent.

I may be representing over flourishing from my unreliable memory, but do you know what I'm talking about? There may be several such cases for all I know.

 

[GeorgCantor]

The only place I know of where one can experiment on a system for which we do not have mere quantum "corrections", but rather where the system is dominated by wild quantum relativistic fluctuations : hadrons.

It so happens that we pretty much have the exact theory describing those beasts : mostly QCD + electroweak corrections.

It turns out that there are pretty much as many hadronic models as there are people trying to model them : we know the relevant fundamental degrees of freedom (quarks and gluons) but we do not know how to calculate the observed properties of the effective degrees of freedom (mesons and baryons).

So an entire community has developed during the last 1.5 decade or so, doing non-perturbative calculations on the lattice. They hope to gather some insights on the effective models, compare their brute-force calculations with predictions which cannot be compared with experiments (either not yet or not in principles), offer guidance in the perturbative to non-perturbative transition.

Those are literally thousands of highly qualified computational scientists. You just dismissed their entire enterprise from a line you picked up in a cartoon ?

Did he really mean to degrade the work of those computational scientists? I thought he meant to expose the common false pretense that a few relations written in mathematical equations(shut up and calculate) give one a picture of what is really going on.

The level of the philosophy sub-forum never ceases to amaze me. It is just plain wrong to have a superficial and distant understanding of what people do (like 99% of the participants of this forum do with Bohr) yet display openly contempt and random judgement on a lifetime's work of Nobel prize winners.

You probably misunderstood what he said. The level of the other sub-forums isn't better at times. If every disagreement that arises in a tread is a testament of someone being wrong, then most threads are filled with at least 50% junk, but that's to be expected at the cutting edge of science.

 

[GeorgCantor]

Which is why, for instance, everyone still things Wave-Particle duality exists.

If we stick to "shut up and calculate" wave particle duality doesn't exist. But i thought people here in the philosophy forum would flat out denounce such an "interpretation" or more appropriately -- such lack of interpretation.


It's more polite to say that fundamental 'particles' display charateristics that don't fall into the realm of comprehensible processes and we have a mathematical model that works but we have no idea why it works. We are trying hard to derive the SE from a more basic and fundamental theory(and make sense of it) but we are unsuccessful.

 

[humanino]

Did he really mean to degrade the work of those computational scientists? I thought he meant to expose the common false pretense that a few relations written in mathematical equations(shut up and calculate) give one a picture of what is really going on.

No, I think I neither misread what he wrote, nor what this implies. Lattice QCD people "shut up and calculate", even more precisely they "expend time and effort performing calculations for a model that [nobody] understand qualitatively".

I find it offensive that people who not only are not professional but do not even know how to calculate dismiss these efforts as "utterly unscientific", and it applies just as well to the Copenhagen school.

Remember Newton knew very well that his "action at a distance" was unsatisfactory ?

I have read as much of Bohr's original texts as I could, and I do not agree that his "shut up and calculate" attitude was inadequate, and I am quite sure that those who believe Bohr was uninterested in philosophy and interpretation are misinformed.

I am not sure about which event Pythagorean is referring to. Again in the topic of hadronic physics, I can mention Yang-Mills theory. When one of them (either Yang or Mills, I am unsure) first presented his work with Pauli in the audience, Pauli used his authority to dismiss it at utter non-sense : there is no other long range force carried by a massless boson. Pauli mentioned that he knew all that business for 30 years, but did not care to publish it. Well, unfortunately for Pauli, massless gluons are confined and Yang-Mills name sticked to the fundamental interaction. It's too bad that the obvious interpretation everybody trusted was flawed. It took about 20 years to understand this aspect, and it was just mathematics missing.By the way, Pauli also dismissed Goudsmit and Uhlenbeck proposal for spin 1/2.

 

[brainstorm]

I find it offensive that people who not only are not professional but do not even know how to calculate dismiss these efforts as "utterly unscientific", and it applies just as well to the Copenhagen school.

Taking offense to methodological criticism is also "utterly unscientific." A disciplined discussion about methodology should explore the reasons for how and why to utilize certain methods in pursuit of certain kinds of knowledge without degenerating into an interest-driven defense of certain methods over others on the basis of their inherent value as methods loose from the specific function they fulfill in specific research endeavors. Generally elevating qualitative or quantitative methods, or any specific method for its own sake is "utterly unscientific" or perhaps "anti-scientific," imo - or actually I think this goes beyond my personal opinion and involves basic issues of reasonability and value/interest-neutrality.

To do good science, you have to know more than just how to perform operations and follow recipes. Technical proficiency has its own value, but it is not inherently good science in itself. Good science involves knowing and reasoning why a particular method is used, quantitative or qualitative (i.e. mathematics or something else); and methodological reasoning cannot be done purely with mathematics, as far as I know. Someone please correct me with an example if I am mistaken.

 

[apeiron]

It so happens that we pretty much have the exact theory describing those beasts : mostly QCD + electroweak corrections.

It turns out that there are pretty much as many hadronic models as there are people trying to model them : we know the relevant fundamental degrees of freedom (quarks and gluons) but we do not know how to calculate the observed properties of the effective degrees of freedom (mesons and baryons).

You seem to be describing a special situation, (much like string theory?), where you have what seems like a concrete beginning (a model of the components), but then no clear path to the next level of description. So a bit like being faced by a combination lock, the only choice seems to be to try every possible combination until one finally clicks.

If this is what you mean by "shut up and calculate", then it sounds like a last resort.

But did the components themselves (QCD) not involve important conceptual leaps? Were the physicists not guided by vague analogies that suggested paths to follow. And then perhaps came the "shut up and calculate" phase where they had to make good on their hopes and intuitions.

 

[Evo]

Is humanino still the only scientist posting in here?

 

[Pythagorean]

Is humanino still the only scientist posting in here?

It depends on how you define scientist. I consider myself a scientist, I'm just not a published scientist (yet). I am, however, doing publishable research through an accredited university, but I don't have a PhD. You could call me a baby scientist without offending me too much. I still have much to learn.

 

[Evo]

It depends on how you define scientist. I consider myself a scientist, I'm just not a published scientist (yet). I am, however, doing publishable research through an accredited university, but I don't have a PhD. You could call me a baby scientist without offending me too much. I still have much to learn.

I define a scientist as someone that is degreed and employed in that science or doing post doctoral work in that science. A BS does not a scientist make, if you are not employed in that field, it is a step in that direction though, IMO. More to the point, this thread is aimed at physicists.


My sister's (now ex) boyfriend has a PhD in astrophysics, both of his parents are tenured professors at a prestigious University. He's never worked a day as an astrophysicist, he delivers pizzas for a living. So is he a scientist or a pizza delivery boy?

My point is that humanino is brilliant in his field, he has refused to accept a Science Advisor medal, but the entire mentor staff acknowledges his brilliance. And then I see posts of members arguing wih him as if they have similar credentials and knowledge.

 

[Pythagorean]

I define a scientist as someone that is degreed and employed in that science or doing post doctoral work in that science. A BS does not a scientist make, IMO. More to the point, this thread is aimed at physicists.

I agree that a BS is insufficient; I consider myself a (baby) scientist because I'm employed in the sciences, not because of the paper.

 

[apeiron]

More to the point, this thread is aimed at physicists.

What the heck is it doing in the philosophy forum then?

 

[humanino]

Generally elevating

What am I elevating ? I am not elevating anything. You are the one elevating :

To do good science, [...] it is not inherently good science in itself. Good science involves knowing and reasoning why a particular method is used, quantitative or qualitative (i.e. mathematics or something else)

I guess you may agree that good science also involve honesty. Sometimes we have methods which provide good answers when compared with data, yet the models do not answer some of our philosophical questions. In that case, it's not that we do not ask the questions, it's just that we are being honest. Some questions are ill-formulated in a given theory. I accept and enjoy criticism. You mention methodology : the method is to understand what people do and then criticize.

You seem to be describing a special situation, (much like string theory?), where you have what seems like a concrete beginning (a model of the components), but then no clear path to the next level of description. So a bit like being faced by a combination lock, the only choice seems to be to try every possible combination until one finally clicks.

Yes.

If this is what you mean by "shut up and calculate", then it sounds like a last resort.

Yes, it is a last resort. There is a difference between not asking a question, and admitting that the theory cannot answer the question.

But did the components themselves (QCD) not involve important conceptual leaps? Were the physicists not guided by vague analogies that suggested paths to follow. And then perhaps came the "shut up and calculate" phase where they had to make good on their hopes and intuitions.

They were guided by precise analogies, the same principles which lead to QED, and a straightforward (in retrospect of course) extension from abelian to non-abelian groups.

 

[Evo]

What the heck is it doing in the philosophy forum then?

The OP is about physics, but doesn't have enough substance for the physics forum. We still need to have some level of scientific merit here. We are lucky enough that a real physicist is sharing here, perhaps we should listen to what they say since they actually work in this field.

That's all I am saying.

 

[apeiron]

The OP is about physics, but doesn't have enough substance for the physics forum.

This is unclear thinking. The OP is clearly about the philosophy of science and the nature of creative genius. Physics might be the domain, but the epistemological questions are more general.

We are lucky enough that a real physicist is sharing here, perhaps we should listen to what they say since they actually work in this field.

Yes, thank-you Humanino.