Does this QM experiment show that science is doomed?

[vanhees71]

Of course not. The scientific method is about what we can learn from observations and building models (and rarely even theories) describing all observations within a consistent mathematical model. If we discover objective deviations between a model (or even a theory) we have to adapt the model (or theory) to the new objective facts. That's not a bug but a feature of science!

 

[Motore]

Because models of science can never 100% tell us how the universe actually works or what constitutes it.

How can they, if they are models. We can refine them with time and knowledge and get them closer (perhaps arbitrarily) to describing objective reality, but the models can never be objective reality.

That's not a bug but a feature of science!

Exactly!

 

[Ibix]

Science is useless in really figuring out anything about the universe.

No - I'm pointing out that it is far and away the best method of figuring out anything about the universe that we have. As evidence, look at all the stuff we can build because of science improving our understanding of how everything works. To say "science is useless because I cannot see how to do one thing I want to do with it" seems rather peculiar to me.

 

[Sunil]

So you are saying that if say somebody asks you what is the smallest unit of matter you have discovered, you have to really say "We really don't know". Because according to your answers "science" actually does not know anything. It just models what it "thinks" is there, but not sure whether "that" is how actually "it" is.

So, if this is how science is done I don't see how it will be any different 100 or 1000 years from now. Even then scientists will still say "we are not sure. It might be this or that".

Doesn't this make this whole business of "science" nothing much to brag about??

What's the big deal then in giving people Nobel Prizes?

The point is that we cannot be sure, certain, that our actually best theories are really true.

Actually, we are even sure that they are not true, given that we have yet open scientific problems - GR cannot be true because it is not a quantum theory, the SM cannot be true because it is not part of a theory which covers gravity, and because it is only an effective field theory, that means, has to be replaced by a better theory below some critical distances (which is guessed to be of order of Planck length).

But even if we would have a theory which does not leave open a single problem of fundamental physics, and which covers everything in fundamental physics, we could not be sure that this theory is the final one. We cannot exclude that tomorrow we will observe something new, not adequately described by that theory.

This is so, and this will remain so forever. But of course we know much more about Nature today. We can make predictions about things we have not even known that they existed at all, and these predictions appear correct if tested. This predictive ability raises. And it gives us a good base for believing that our best existing theories are, even if not true, then at least good approximations of reality.

 

[DennisN]

Doesn't this make this whole business of "science" nothing much to brag about??

In 1969 humans visited another celestial body for the first time in history, the Moon (Apollo 11).
All thanks to science and technology. And if I remember correctly they used Newtonian physics for computing the flight, landing etc. That's quite something to brag about, in my opinion.

What's the big deal then in giving people Nobel Prizes?

In 1956, John Bardeen, Walter Brattain and William Shockley got the Nobel Prize in physics for their work on developing the transistor.

And the thing you are using for posting on this forum (e.g. computer, tablet or mobile phone etc.) are full of - guess what?

Transistors.

 

[Vanadium 50]

I am bit confused.

So you are saying that if say somebody asks you what is the smallest unit of matter you have discovered, you have to really say "We really don't know". Because according to your answers "science" actually does not know anything. It just models what it "thinks" is there, but not sure whether "that" is how actually "it" is.

So, if this is how science is done I don't see how it will be any different 100 or 1000 years from now. Even then scientists will still say "we are not sure. It might be this or that".

Doesn't this make this whole business of "science" nothing much to brag about??

What's the big deal then in giving people Nobel Prizes?

We get this a lot here. I mentally categorize these messages as "if we don't know everything, we don't know anything." It's not a very good argument.

 

[francis20520]

We get this a lot here. I mentally categorize these messages as "if we don't know everything, we don't know anything." It's not a very good argument.

This view is not correct.

I am not saying that science should know everything.

My problem is that even the things you say you "know" (like electrons, protons etc, GR and QM etc) exist in reality, now under close questioning seem to be just mathematical models of reality, but not reality itself.

If a proton is a "model"and NOT real, then what you are saying is that you really don't know whether things called protons exist.

To me this is a big problem. Because then no matter how much science you do, science can never, I mean NEVER, say with certainty what "reality" is.

This places science as a sort of "engineering" tool.

You can do stuff with it but only "approximate" reality with models.

If children are told THIS in school I don't think many would opt to become scientists.

 

[Ibix]

My problem is that even the things you say you "know" (like electrons, protons etc, GR and QM etc) exist in reality, now under close questioning seem to be just mathematical models of reality, but not reality itself.

The question is how solipsistic you want to get. Do you know that the chair you are sitting in exists? You've only got your sensory impressions to go on, so you could be trapped in the Matrix, for example. A really simple model of the world, consistent with everything you know, is that the chair exists. But you cannot formally discount the Matrix possibility. "The chair exists" is only a model.

Protons are the same as the chair. They are a model that explains our sensor data, but we cannot exclude the possibility that they cannot explain some hypothetical future sensor data (arguably the fact that they are made up of quarks already is such data). The only difference from the chair is that the model was formally constructed and recognised as such, rather than being a product of whatever ad hoc processes our brains provide.

 

[Vanadium 50]

I refuse to argue with a brain in a vat.

 

[Lord Jestocost]

To me this is a big problem. Because then no matter how much science you do, science can never, I mean NEVER, say with certainty what "reality" is.

That's the point. As Byron K. Jennings puts it in “Defense of Scientism: An Insider's view of Science”:

"Contrary to popular opinion, the scientific method does not assume materialism, realism, or any other -ism. All one needs to carry out science are observations that can be used to construct and test models. Whether the observations are the result of a material world impinging on the mind through the senses, or purely illusions of the mind as in solipsism, does not really matter. The relationship between the models and reality is different for each of the options one through five [materialism, idealism, solipsism, deism, theism, LJ], but observation cannot discriminate between them." [bold by LJ]

 

[Nugatory]

To me this is a big problem. Because then no matter how much science you do, science can never, I mean NEVER, say with certainty what "reality" is.

That is why we have another field of intellectual effort, called philosophy.

if you’re a physicist you get to say, with varying but generally high and improving levels of certainty, how the universe behaves.

 

[DennisN]

If a proton is a "model"and NOT real, then what you are saying is that you really don't know whether things called protons exist.

We know that there is a (what we call) positively charged nucleus in all atoms*, and the most simple atom, hydrogen, has a nucleus with charge +e (proton). We also know there are (what we call) negatively charged particles with the charge -e. We call them electrons. These particles turn up in a bunch of experiments.

For an intro to the background on the early probings of the atom and electron, check out e.g.:

• Rutherford scattering
• Discovery of electrons (Britannica)
• Oil Drop Experiment

* Edit: When I wrote I meant atoms of "normal" matter. There can also be antimatter, where the charges are reversed (antiprotons with the charge -e, and positrons (antielectrons) with the charge +e).

 

[francis20520]

The question is how solipsistic you want to get. Do you know that the chair you are sitting in exists? You've only got your sensory impressions to go on, so you could be trapped in the Matrix, for example. A really simple model of the world, consistent with everything you know, is that the chair exists. But you cannot formally discount the Matrix possibility. "The chair exists" is only a model.

Protons are the same as the chair. They are a model that explains our sensor data, but we cannot exclude the possibility that they cannot explain some hypothetical future sensor data (arguably the fact that they are made up of quarks already is such data). The only difference from the chair is that the model was formally constructed and recognised as such, rather than being a product of whatever ad hoc processes our brains provide.

I am NOT a solipsistic. From my understanding of philosophy solipsism was successfully refuted long time ago. But of course Matrix scenario (i.e. world is a computer simulation) has not so far been refuted. But even if we are a in a simulation then that will be our reality. So simulation hypothesis has no affect on anything we are discussing.

The thing is, when we are told in school that protons exist, we actually think they really exist.

Of course now we are told it's not the case.

I feel that we are actually "fooled" in school and even in university.

 

[George Jones]

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[DrChinese]

The thing is, when we are told in school that protons exist, we actually think they really exist.

Of course now we are told it's not the case.

I feel that we are actually "fooled" in school and even in university.

Protons exist. The model of the proton has evolved over time, and there are multiple models in use depending on needs. No one is fooling anyone.

 

[vanhees71]

That's the point. As Byron K. Jennings puts it in “Defense of Scientism: An Insider's view of Science”:

"Contrary to popular opinion, the scientific method does not assume materialism, realism, or any other -ism. All one needs to carry out science are observations that can be used to construct and test models. Whether the observations are the result of a material world impinging on the mind through the senses, or purely illusions of the mind as in solipsism, does not really matter. The relationship between the models and reality is different for each of the options one through five [materialism, idealism, solipsism, deism, theism, LJ], but observation cannot discriminate between them." [bold by LJ]

As I said before, that's a feature not a bug of the scientific method!

 

[PeterDonis]

Of course now we are told it's not the case.

Who is saying protons do not exist?

 

[Lord Jestocost]

Protons exist...

But not as objects which can be given a description in their own right.

 

[francis20520]

But not as objects which can be given a description in their own right.

Are you saying that "protons exist" is not the same as "tables exist"??

Then how exactly do protons exist??

 

[Lord Jestocost]

To merely say that something “exists” lacks a sense of direction when one doesn't make any claims concerning the character of this existence, i.e. how it exists.

 

[PeterDonis]

Since we are getting into a discussion of what "exists" means, this thread belongs in the QM interpretations forum. So I have moved it there.

 

[Vanadium 50]

Who is saying protons do not exist?

Are you saying that "protons exist" is not the same as "tables exist"??

I think this is arguing against tables existing. After all, we have ~10²⁰ pieces of evidence that protons exist but only ~10¹⁰ that tables exist.

 

[PeterDonis]

I think this is arguing against tables existing.

If @Lord Jestocost does indeed want to argue that tables don't exist, I'll ask him to bang his head on one and then see if he still thinks so.

 

[Lord Jestocost]

Then how exactly do protons exist??

To my mind, questions like „How exactly do protons, neutrons, electrons or atoms etc. exist?“ cannot be answered. Here, I am following Paul Davies who puts it in the following way (in his introduction to Werner Heisenberg’s “Physics and Philosophy”, Penguin Books):

“By contrast, the Copenhagen interpretation of quantum mechanics, which Heisenberg here expounds so lucidly, rejects the objective reality of the quantum microworld. It denies that, say, an electron has a well-defined position and a well-defined momentum in the absence of an actual observation of either its position or its momentum (and both cannot yield sharp values simultaneously). Thus an electron or an atom cannot be regarded as a little thing in the same sense that a billiard ball is a thing. One cannot meaningfully talk about what an electron is doing between observations because it is the observations alone that create the reality of the electron. Thus a measurement of an electron's position creates an electron-with-a-position; a measurement of its momentum creates an electron-with-a-momentum. But neither entity can be considered already to be in existence prior to the measurement being made.
What, then, is an electron, according to this point of view? It is not so much a physical thing as an abstract encodement of a set of potentialities or possible outcomes of measurements. It is a shorthand way of referring to a means of connecting different observations via the quantum mechanical formalism. But the reality is in the observations, not in the electron.”

Or, to cite John Archibald Wheeler:

“In today’s words Bohr’s point – and the central point of quantum theory – can be put into a single, simple sentence. ‚No elementary phenomenon is a phenomenon until it is a registered (observed) phenomenon.‘“

Wheeler, J.A. (1983) in “Law without law”, in Wheeler and Zurek (eds.), Quantum Theory and Measurement, Princeton University Press, 182–213.

 

[francis20520]

To my mind, questions like „How exactly do protons, neutrons, electrons or atoms etc. exist?“ cannot be answered. Here, I am following Paul Davies who puts it in the following way (in his introduction to Werner Heisenberg’s “Physics and Philosophy”, Penguin Books):

“By contrast, the Copenhagen interpretation of quantum mechanics, which Heisenberg here expounds so lucidly, rejects the objective reality of the quantum microworld. It denies that, say, an electron has a well-defined position and a well-defined momentum in the absence of an actual observation of either its position or its momentum (and both cannot yield sharp values simultaneously). Thus an electron or an atom cannot be regarded as a little thing in the same sense that a billiard ball is a thing. One cannot meaningfully talk about what an electron is doing between observations because it is the observations alone that create the reality of the electron. Thus a measurement of an electron's position creates an electron-with-a-position; a measurement of its momentum creates an electron-with-a-momentum. But neither entity can be considered already to be in existence prior to the measurement being made.
What, then, is an electron, according to this point of view? It is not so much a physical thing as an abstract encodement of a set of potentialities or possible outcomes of measurements. It is a shorthand way of referring to a means of connecting different observations via the quantum mechanical formalism. But the reality is in the observations, not in the electron.”

Or, to cite John Archibald Wheeler:

“In today’s words Bohr’s point – and the central point of quantum theory – can be put into a single, simple sentence. ‚No elementary phenomenon is a phenomenon until it is a registered (observed) phenomenon.‘“

Wheeler, J.A. (1983) in “Law without law”, in Wheeler and Zurek (eds.), Quantum Theory and Measurement, Princeton University Press, 182–213.

But then, if elementary particles do not "exist" then how come macroscopic things like tables and humans exist? We know for sure that tables and other people exist.

Another question is how does a light source emit photons when according
to you those photons don't really exist until they are "observed"?

How can a macroscopic light source create non-existing photons?
I.e. How do you create "non-existing" elementary particles? If you create something then by definition it has to exist, right?

 

[Lord Jestocost]

But then, if elementary particles do not "exist" then how come macroscopic things like tables and humans exist?

Maybe, you completely misunderstand me. To me the term “existence” means nothing else than the capacity to have effects upon the world with which we “interact”. As a physicist, however, I avoid to make any claims concerning the character of this existence, call it an instrumentalist’s point of view (https://en.wikipedia.org/wiki/Instrumentalism). As Bernard d'Espagnat remarks in "Quantum weirdness: What we call 'reality' is just a state of mind":
"This reality is something that, while not a purely mind-made construct as radical idealism would have it, can be but the picture our mind forces us to form of ... Of what? The only answer I am able to provide is that underlying this empirical reality is a mysterious, non-conceptualisable "ultimate reality", not embedded in space and (presumably) not in time either."
(https://www.theguardian.com/science/blog/2009/mar/17/templeton-quantum-entanglement)

 

[vanhees71]

Well, elementary particles indeed have "effects upon the world with which we interact". How else would we have discovered all these critters over the decades?

 

[Lord Jestocost]

Regarding the notion "elementary particles" which is used as a matter of convenience, Paul Davies brings it to the point (in his introduction to Werner Heisenberg’s “Physics and Philosophy”, Penguin Books):

“And so the language of quantum mechanics employs familiar words, such as wave, particle, position, etc., but their meanings are severely circumscribed and often vague. Heisenberg warns us that: 'When this vague and unsystematic use of language leads us into difficulties, the physicist has to withdraw into the mathematical scheme and its unambiguous correlation with experimental facts.'”

 

[berkeman]

Thread closed for Moderation...

Edit/Update -- after a Mentor discussion, the thread will remain closed.