The Schroedinger Equation is the most true thing I've ever encountered. It is clear, simple, obvious in its correctness; the greatest piece of physics since Maxwell. Once you've understood it it becomes almost impossible to imagine that the universe could possibly work any other way. (Contrary to this article's claim, the equation describes the behaviour of Helium atoms perfectly well; it's a failure of our imagination or exertion that we can't find closed-form stable solutions, not a fact about the equation itself). So this kind of complaint seems utterly wrongheaded.
People hold quantum mechanics to some ridiculous standard, far higher than any other physical theory. Did they really expect that the behaviour of the very small would be exactly like that of everyday macroscopic objects? Do they enjoy the mysticism of pretending that it's complex and hard to understand when it's really nothing of the sort? Frankly I think an honest approach to QM would present it as something banal and obvious.
> In the coming sequence on quantum mechanics, I am going to consistently speak as if quantum mechanics is perfectly normal; and when human intuitions depart from quantum mechanics, I am going to make fun of the intuitions for being weird and unusual.
That's a little bit of a stretch, don't you think?
I mean, here are questions about the SE I've so far never received simple, intuitive answers to:
- Why do we need complex numbers in the SE, what do they bring to the table and how does that tie in with physical intuition?
- How was the equation derived, intuitively?
- The laplacian in there feels like it's a "diffusion" term (as in the heat equation, things tend to spread and smoothen over time). Why isn't there ever a intuitive explanation in text books about this?
- [edit]: Many book trumpet that classical mechanics is just an approximation of QM, but unlike in special relativity where speed going to zero obviously gets you back to classical mechanics, I've never seen a clear example of a system where the quantum behavior "transitions" to classical behavior as a variable (e.g size) increases or decreases.
- the list is long
> Did they really expect that the behaviour of the very small would be exactly like that of everyday macroscopic objects?
I expect a theory predicting otherwise to bear the burden of demarcating exactly where the boundary between "macroscopic" and "weird not-macroscopic" lies (waving your hands and mumbling "thermodynamics" does not count). I expect that such a theory's proponents should be absolutely burning with interest in probing, studying and understanding what goes on at this peculiarly discontinuous boundary in Nature.
Those two things haven't happened, which is kind of sad.
Quantum Mechanics predicts the results of experiments better than anything else. If "predicts experimental results" is the only thing you care about, then Bohr was right, QM is complete, and there's nothing more to be written in that book.
>Contrary to this article's claim, the equation describes the behaviour of Helium atoms perfectly well;
Yes, I was disappointed to read this as well. I suspect what he meant is that we can't derive closed form solutions for the Schrödinger equation in the case of the Helium atom.
But the equation can perfectly be integrated numerically ... in these days of rather powerful computers, closed-form solutions to diffeqs aren't as important as they used to. As a matter of fact, for most problems in QM, I suspect there's just no other way.
One step further, when reading QM books, there seem to be a strong tendency to try and assign "physical meaning" to purely mathematical techniques used to find closed form solution to diffeqs (eg separation of variables). I am not convinced that it is a fruitful endeavor.
Another reason he may be saying this could also be because with the Schrödinger equation for the Helium atom, assuming it isn't separable along space variables, the solution ψ is a map from the configuration space, (i.e. ℝ6) to ℂ, something that's hard and annoying to visualize, whereas for the Hydrogen atom, you can draw pretty orbital probability density pictures in ℝ3, something everyone can "understand".
If you go back in the past, contemporaries of newton were critical of his gravitational theory having an instantaneous action at a distance. Familiarity has just bled us of its strangeness over time.
What's natural about SE? From my limited understanding, SE tells us that all particles in the world are interconnected in a peculiar way by a "energy field" of some sort.
Not sure I agree with him. What does something being real mean? It's got to mean that observations are consistent with the description of that something. That's actually all we can do, check that observations aren't disagreeing with what the model said. So if an electron is a tiny little thing that is deflected by a magnetic field, has a certain mass, etc, then it's real insofar as we observe those qualities. In the same way if Santa Claus isn't real, it's because there's issues with the evidence.
This doesn't preclude there being a better model of course. Observations can get more sophisticated, revealing that your model needed adjustment. Or parsimony can drive and someone finds a way to describe multiple phenomena at once, eg electromagnetism.
As for why mathematics is great at describing nature, it's because there's loads of it, since it's an extensible system of logic. Someone somewhere is going to find a way of describing how asteroids go round, and being a kind of logic there's no way you would say it wasn't math, regardless of what exactly it was. Epicycles are math too, despite not being the exact right way to think about it.
Physical theories often go beyond just predictions, and attempt to specify a correspondence between a formalism and physical reality.
Quarks are an example. Quarks were conceptualized as a mathematical simplification, and only later were recognized as real physical things - or at least as real as protons.
In QM we have physical quantities (an electron's mass) and unphysical quantities (an electron's phase). But there's open questions, like the wavefunction - can that be placed in correspondence with reality? We don't really know. This is the "ontic" vs "epistemic" debate.
>Mathematical models such as quantum mechanics and general relativity work, extraordinarily well. But they aren’t real in the same sense that neutrons and neurons are real
Why not? When you really get down to it, aren't both neutrons and neurons ultimately also models?
When most people think of a neutron, they think of a classical particle, yet we know experimentally that there is no such thing.
Indeed, and the Schrodinger equation is well behind Quantum Field Theory (the most modern quantum theory).
In QFT, particles can be interpreted to not exist, only fields -- particles are just a fuzzy (imperfect) abstraction of "field excitations". Particles may exist in the path-integral formulation of QM however. But it known among physicists that particles or fields don't define what is real -- what it matters is that the models predict observations. It is irrelevant which model is 'true' -- if they give equivalent results, both can be said to be [indistinguishably] correct (in their relevant domain). The examples go back a long way too, e.g. with the Hamiltonian and Lagrangian formulations of classical mechanics (wildly different but compatible mathematical formulations) -- so the 'model paradigm' has been known to physicists for a while.
I think in physics 'truth' is understood to be a (possibly non-unique) model that in principle would provide an exact prediction under ideal conditions, for a limited experiment. In our reality the ideal conditions are never going to be met. For example, we cannot ensure that a system has every atom in a certain position before performing an experiment (in fact the known quantum principles of physics themselves would contradict this); we might in theory know of a generalized state of a system (quantum superposition), but even then there are too many other assumptions (about experimental devices, about the individuals reading the experiments, about science as a whole) that go into the experimental paradigm.
I still find truth (as given) a useful concept, as a metaphysical principle that reality exists and has some working real mechanism (defined as being mathematically describable) -- we may never we able to write it down or discover it entirely, but it exists. Try to imagine an universe that is indescribable in principle (yields contradiction). There must be a rule.
Without getting into the pedantics of the specific examples, I'm sure you intuitively understand the difference between a exact value and an approximation, likewise discrete values and a fitted curve.
The argument is that models are only useful tools and should not be taken to be a full or only representation of the thing being studied.
I personally came to a conclusion, that "true" is not a word to apply to a physics equation. Truth is a mathematical abstraction, which is useful often, but to speak about truth we need to assume as given some other truths and call them axioms. In this sense almost anything could be true given the right axioms. The article seems to be confused and mixes ideas like "true", "real" and "valid". Math statements might be true. Physics theories might be valid. What is real is a deep philosophical question and the answer... well, it depends...
There is truth outside of mathematics, as philosophers have fought toiled with this idea. Famously Descartes with his root of skepticism being a kind of Identity/Existence truth.
I mean in some ways Mathematics is just like a completely made up world that is internally consistent so saying it is "truth" is the same as me saying "in a made up world where truth exists, truth exists"
Is this another way of saying "All models are wrong, but some are useful."
Us mathematically, and computer inclined people like to think math has a sort of universal truth to it. But it only has truth within the bounds of it's own system, or it would break one of Godel's incompletness theorems, right?
As I write this, I'm kind of thinking that the "All models are wrong" George Box quote is almost a statement of Godel's theorem.
The article touches upon something that I think most people that learn about physics don't realize. The models physicists use to describe nature do NOT exist in reality. They are mere concepts that work well to describe natural phenomena.
My favourite example for this is the electron. Does an electron how we describe it in quantum mechanics exist in nature? The answer is no. The electron is a model construct we have made up that describes natural phenomena. Nothing more.
This is where non-experts that didn't study physics get confused when they read that an electron is a wave but also a particle. All of these concepts are just physical models that again do not exist in nature. But they describe different aspects of nature pretty well. And so we assign them a meaning beyond what the mathematical or physical model contains, a part of reality.
The world that see you when looking out through your eyes doesn't exist in reality either. It's just models your brain puts together from some sensory stimuli (photons hitting your retina), but they aren't real, they are mere concepts that happen to work well enough that you may manage to live long enough to procreate... they were made by evolution, and evolution doesn't care if it's real so long as it works well enough.
I don't think it's meaningful to say that the electron described by QM doesn't exist in nature... something exists in nature and all we can ever do is describe it with a model.
>>> The article touches upon something that I think most people that learn about physics don't realize. The models physicists use to describe nature do NOT exist in reality. They are mere concepts that work well to describe natural phenomena.
Indeed, having completed a graduate degree in physics, by the time you've been introduced to a different model of the electron for the third or fourth time, it begins to sink in.
Physics isn't special in this regard, though. All conscious thought is about models, abstractions and filing things away in boxes. I might think this post of mine starts with the letter P, but if I made the http request by hand, starting it by sending the utf8 encoding of P to the network card won't work, because I need headers. On the other hand if my child tried to render the opening P I'd ask her to not draw on my phone screen please.
Well technically I think the answer would he "We don't know" instead. We don't have anything better than the standard model - the perceived clash between wave and particle is resolved by a more general theoryz for example.
This all depends on your philosophy and definition of reality. When you get into stuff as far from everyday life as electrons, our intuitive definitions don't work very well.
Most scientists, I think, use some definitions along the lines of "Reality is whatever appears in our best models/explanations of our observations of the world".
If all observations of electrons we have ever made obey some law, we say that's the real behaviour of electrons. If we find out it doesn't always work, we realize reality is something more complex, and at some point hopefully we find out what it is.
> The “laws” of physics, Wigner adds, have little or nothing to say about biology, and especially about consciousness, the most baffling of all biological phenomena.
Starting with the laws of physics, no, we cannot in practice calculate a consciousness. But we also can't inspect a lottery machine and predict the balls which come out either. Nobody thinks the latter is is because lottery machines also contain magic, yet so many people think that of consciousness.
Could consciousness involve extra-physical explanation? Sure. But there there is an equal amount of evidence that lottery machines do too (i.e., none).
I dislike this comparison. The reason we can't explain consciousness isn't because it complex or because there are too many variables for us to track and predict, as in the case of the lottery machine, but because we haven't decided what we mean when we say 'conciousness'. Pretty much any component of consciousness one may think of can be explained in isolation as a simple material system. Self-reflection, continuity, response to stimuli, etc.
When people talk about magic, they are referring to the strangeness of subjectivity, and what it is at a very fundamental level. I think a better analogy is being a Greek philosopher and trying to understand what matter is. No tool at the time can measure things in a way that would meaningfully lead them to an answer, nor did they have any theories where matter could be related to something they could study. So when we are confronted with the same situation, I think it's perfectly reasonable to assume that we, like them, are missing a massive piece of the puzzle. Calling it magic feels kind of right when it's something so large and consequential.
> If physicists adopt this humble mindset, and resist their craving for certitude, they are more likely to seek and hence to find more even more effective theories, perhaps ones that work even better than quantum mechanics.
Why thank you, Mr. Science Communicator. Such a tremendous insight that all I needed was a mindset to find, eh, quantum field theory?
(Apologies for the sarcasm, but - really?)
(Also: no disrespect intended to (other) science communicators.)
I think you should watch/read Sabine Hossenfelder.
She is cold, methodical, and notably critical of the search for mathematical beauty.
She is pretty clear about the fact that reality is what we observe, and equations are just a tool we use to make models.
Mathematics is uniquely weird in that anywhere in the universe, a species can come up with the same things... So to say Mathematics is not real, and yet it is independently discoverable by anyone is just really weird to me.
If you read Wigner's famous essay, you can make an argument that if not the mathematics itself, there is some kind of structure which is mathematical if not symbolic.
>If physicists adopt this humble mindset, and resist their craving for certitude, they are more likely to seek and hence to find more even more effective theories, perhaps ones that work even better than quantum mechanics.
I don't believe that most modern physicists dispute that the equations we use are anything more than models. For example, you won't go to a seminar on microrheology and have a physicists point out in disgust that the presented derivation is "wrong" because it used Newton's second law without the relativistic component. While this is perhaps an extreme example, it is the case that we often have to ignore certain effects/make certain assumptions to make equations solvable and interpretable. If we believed that our physics equations represented some "absolute truth," then we would never allow ourselves to make these sort of assumptions in the formulas we derive.
Reminds me of course of the great anecdote attributed to quantum physicist Wolfgang Pauli:
"a friend showed Pauli the paper of a young physicist which he suspected was not of great value but on which he wanted Pauli's views. Pauli remarked sadly, 'It is not even wrong'."
I've seen a clever mathematical trick that derives the Schrodinger equation out of GR. As you know, there's this invariant interval thing: ds2 = c2 dt2 - dx2 - dy2 - dz2. The trick was to add a small oscillation multiplier to ds2, so it would become ds2 exp(a cos wt) = ... Mixed with lorentz transforms, this yields the static SE and mixed with GR tensors stuff this yields the time dependent SE. I can't judge if this trick is physically sound.
This seems to be a more reasonable approach - derive a relation from a law of conservation. Starting from the differential form is fraught with indeterminism. Assuming this works, I wonder about maxwell’s equations. I assume they would have to be consistent with a conserved electromagnetic quantity added into this. Gravity?
Toss a ball in the air and watch it spin. You ask why it spins and I tell you that it is because god is multiplying its state by a quarternion. Is that true?
An equation can be perfectly descriptive without explaining anything, and just as easily used in a patently incorrect or at least unverifiable explanation. A new physics learner may be uncomfortable with this notion, as everything up to that point was taught as cause and effect, no difference between explanation and description. As in the example, the description could take a different form. God could use matrices. Or you could say that god prefers to minimize the lagrangian. Or you could simulate with finite element analysis and say that it is an emergent phenomenon of many points of mass all following a set of rules. Questions for each explanation abound. I think at the bottom of all of this there has to be an admission that the universe works in this particular manner because it wouldn’t exist for us any other way, and we do exist, so it must.
It's a lovely mysterious incantation, like the (worked-over by Heaviside) Maxwell equations. But (used much like Latin), they don't speak to any human beings except those that have the leisure and capacity to learn all that math ... and then to acquire a voluminous mental store of evidence to apply it to. Real truth is plain.
Newton's equations are approachable, closer to human experience and comprehension. Feynman's diagrams, perhaps a step in the right direction.
True? Science is not math; it has no proofs. A 'theory' is the expression of a model that's stood the test of time - but one piece of evidence can force it to be re-built. Science forces us to search for and adapt to the new. Feynman said, "When someone says ‘science teaches such and such’, he is using the word incorrectly. Science doesn’t teach it; experience teaches it."
Well. Anecdotally, when there's open house at the physics department, the guys that will tell you how quantum mechanics and/or relativity are wrong tend to have a background in engineering.
Also note that not everyone subscribes to what the article calls the 'Gospel of Physics': Quite a few of us are well-aware that the map is not the territory...
The author of this piece says he was struggling to understand complex conjugates. If you don't understand what that is, please read the wikipedia, so you can contextualize his level of familiarity with the material he speaks about.
I don't think the author is being dishonest. But that admission is extremely striking to me.
[edit: Can some admin give me guidance on how to make the point I'm clearly trying to make? I'm not sure how to make this point without being discourteous.]
I mean.. if their problem is not understanding the math of conjugation at all, then yes, they're pretty elementary and are going to have trouble with QM.
But if their problem is not being able to stomach the "just-because" explanations that every QM resigns to using to explain wtf complex conjugation has to do with reality, then I completely, totally sympathize. Learning QM consists of learning to silence your objections to the fact that none of the things you're being asked to believe make any sense.
It gets somewhat more scrutable when you deal with relativistic QM, where, at least, the terms in Schrodinger equation start to make intuitive sense (it's the first couple terms in the Taylor expansion of E psi = sqrt(p^2 + m^2) psi = m sqrt(p^2/m^2 + 1) psi = (m + 1/2 p^2/m)psi ), but then spinors enter the picture and all intuition goes out the window again.
All of the philosophical complexity the author finds here can also be found in Newtonian mechanics. Papers are still being published today about the philosophy of Newtonian mechanics, using it as a gateway and simple test piece for the philosophy of physics or science overall. A common mistake among, I guess you could call them "rookie philosophers of science," is to look for the grandest examples of the problems they study, and overlook the simplest places where the problem is exhibited. The best philosophy deals with the simplest materials possible, no more than is required to build the case being made.
John Horgan is a long established and excellent science writer, and given that he's commenting on philosophical issues here as much as anything, I don't agree his difficulty with some mathematical elements of the subject - which he's gracious enough to commit to learning, and humble enough to admit to struggling with - affects his point, which isn't without merit.
But can you call a theory true if no one understands it? A century after inventing quantum mechanics, physicists still squabble over what, exactly, it tells us about reality.
I think his question is a little loaded - it's a cliché that "nobody understands it", and I'm sure there are physicists who would bridle a little at that being true.
His following claim (disputes over what it tells us) - while true - is not quite the same thing, so the argument is flawed in that regard, but not because of a problem learning maths.
I also find it disingenuous that he dismisses the square-root of negative one as "imaginary" (not real), but doesn't appear to have a problem with algebraic numbers, negative numbers, or fractions (all of which are also extensions of the base ring). I'm trying to imagine how he'd feel about incomputable normal numbers...
[+] [-] lmm|5 years ago|reply
People hold quantum mechanics to some ridiculous standard, far higher than any other physical theory. Did they really expect that the behaviour of the very small would be exactly like that of everyday macroscopic objects? Do they enjoy the mysticism of pretending that it's complex and hard to understand when it's really nothing of the sort? Frankly I think an honest approach to QM would present it as something banal and obvious.
[+] [-] FeepingCreature|5 years ago|reply
> In the coming sequence on quantum mechanics, I am going to consistently speak as if quantum mechanics is perfectly normal; and when human intuitions depart from quantum mechanics, I am going to make fun of the intuitions for being weird and unusual.
[+] [-] ur-whale|5 years ago|reply
That's a little bit of a stretch, don't you think?
I mean, here are questions about the SE I've so far never received simple, intuitive answers to:
[+] [-] KirillPanov|5 years ago|reply
I expect a theory predicting otherwise to bear the burden of demarcating exactly where the boundary between "macroscopic" and "weird not-macroscopic" lies (waving your hands and mumbling "thermodynamics" does not count). I expect that such a theory's proponents should be absolutely burning with interest in probing, studying and understanding what goes on at this peculiarly discontinuous boundary in Nature.
Those two things haven't happened, which is kind of sad.
Quantum Mechanics predicts the results of experiments better than anything else. If "predicts experimental results" is the only thing you care about, then Bohr was right, QM is complete, and there's nothing more to be written in that book.
[+] [-] millstone|5 years ago|reply
[+] [-] ur-whale|5 years ago|reply
Yes, I was disappointed to read this as well. I suspect what he meant is that we can't derive closed form solutions for the Schrödinger equation in the case of the Helium atom.
But the equation can perfectly be integrated numerically ... in these days of rather powerful computers, closed-form solutions to diffeqs aren't as important as they used to. As a matter of fact, for most problems in QM, I suspect there's just no other way.
One step further, when reading QM books, there seem to be a strong tendency to try and assign "physical meaning" to purely mathematical techniques used to find closed form solution to diffeqs (eg separation of variables). I am not convinced that it is a fruitful endeavor.
Another reason he may be saying this could also be because with the Schrödinger equation for the Helium atom, assuming it isn't separable along space variables, the solution ψ is a map from the configuration space, (i.e. ℝ6) to ℂ, something that's hard and annoying to visualize, whereas for the Hydrogen atom, you can draw pretty orbital probability density pictures in ℝ3, something everyone can "understand".
[+] [-] salty_biscuits|5 years ago|reply
[+] [-] dls2016|5 years ago|reply
You better not say that when any solitons are floating by...
[+] [-] frongpik|5 years ago|reply
[+] [-] andi999|5 years ago|reply
[+] [-] lordnacho|5 years ago|reply
This doesn't preclude there being a better model of course. Observations can get more sophisticated, revealing that your model needed adjustment. Or parsimony can drive and someone finds a way to describe multiple phenomena at once, eg electromagnetism.
As for why mathematics is great at describing nature, it's because there's loads of it, since it's an extensible system of logic. Someone somewhere is going to find a way of describing how asteroids go round, and being a kind of logic there's no way you would say it wasn't math, regardless of what exactly it was. Epicycles are math too, despite not being the exact right way to think about it.
[+] [-] millstone|5 years ago|reply
Quarks are an example. Quarks were conceptualized as a mathematical simplification, and only later were recognized as real physical things - or at least as real as protons.
In QM we have physical quantities (an electron's mass) and unphysical quantities (an electron's phase). But there's open questions, like the wavefunction - can that be placed in correspondence with reality? We don't really know. This is the "ontic" vs "epistemic" debate.
[+] [-] aeternum|5 years ago|reply
Why not? When you really get down to it, aren't both neutrons and neurons ultimately also models?
When most people think of a neutron, they think of a classical particle, yet we know experimentally that there is no such thing.
[+] [-] gnramires|5 years ago|reply
In QFT, particles can be interpreted to not exist, only fields -- particles are just a fuzzy (imperfect) abstraction of "field excitations". Particles may exist in the path-integral formulation of QM however. But it known among physicists that particles or fields don't define what is real -- what it matters is that the models predict observations. It is irrelevant which model is 'true' -- if they give equivalent results, both can be said to be [indistinguishably] correct (in their relevant domain). The examples go back a long way too, e.g. with the Hamiltonian and Lagrangian formulations of classical mechanics (wildly different but compatible mathematical formulations) -- so the 'model paradigm' has been known to physicists for a while.
I think in physics 'truth' is understood to be a (possibly non-unique) model that in principle would provide an exact prediction under ideal conditions, for a limited experiment. In our reality the ideal conditions are never going to be met. For example, we cannot ensure that a system has every atom in a certain position before performing an experiment (in fact the known quantum principles of physics themselves would contradict this); we might in theory know of a generalized state of a system (quantum superposition), but even then there are too many other assumptions (about experimental devices, about the individuals reading the experiments, about science as a whole) that go into the experimental paradigm.
I still find truth (as given) a useful concept, as a metaphysical principle that reality exists and has some working real mechanism (defined as being mathematically describable) -- we may never we able to write it down or discover it entirely, but it exists. Try to imagine an universe that is indescribable in principle (yields contradiction). There must be a rule.
It also sets the standard for our models.
https://chem.tufts.edu/answersinscience/relativityofwrong.ht...
[+] [-] uoaei|5 years ago|reply
This is not the case.
This is a simple example of how hard quantum mechanics is to think about.
[+] [-] jayd16|5 years ago|reply
The argument is that models are only useful tools and should not be taken to be a full or only representation of the thing being studied.
[+] [-] ordu|5 years ago|reply
[+] [-] onethought|5 years ago|reply
I mean in some ways Mathematics is just like a completely made up world that is internally consistent so saying it is "truth" is the same as me saying "in a made up world where truth exists, truth exists"
[+] [-] discodave|5 years ago|reply
Us mathematically, and computer inclined people like to think math has a sort of universal truth to it. But it only has truth within the bounds of it's own system, or it would break one of Godel's incompletness theorems, right?
As I write this, I'm kind of thinking that the "All models are wrong" George Box quote is almost a statement of Godel's theorem.
[+] [-] brummm|5 years ago|reply
My favourite example for this is the electron. Does an electron how we describe it in quantum mechanics exist in nature? The answer is no. The electron is a model construct we have made up that describes natural phenomena. Nothing more.
This is where non-experts that didn't study physics get confused when they read that an electron is a wave but also a particle. All of these concepts are just physical models that again do not exist in nature. But they describe different aspects of nature pretty well. And so we assign them a meaning beyond what the mathematical or physical model contains, a part of reality.
[+] [-] jbotz|5 years ago|reply
I don't think it's meaningful to say that the electron described by QM doesn't exist in nature... something exists in nature and all we can ever do is describe it with a model.
[+] [-] analog31|5 years ago|reply
Indeed, having completed a graduate degree in physics, by the time you've been introduced to a different model of the electron for the third or fourth time, it begins to sink in.
[+] [-] sideshowb|5 years ago|reply
[+] [-] mhh__|5 years ago|reply
Well technically I think the answer would he "We don't know" instead. We don't have anything better than the standard model - the perceived clash between wave and particle is resolved by a more general theoryz for example.
[+] [-] thomasahle|5 years ago|reply
Most scientists, I think, use some definitions along the lines of "Reality is whatever appears in our best models/explanations of our observations of the world".
If all observations of electrons we have ever made obey some law, we say that's the real behaviour of electrons. If we find out it doesn't always work, we realize reality is something more complex, and at some point hopefully we find out what it is.
[+] [-] tasty_freeze|5 years ago|reply
Starting with the laws of physics, no, we cannot in practice calculate a consciousness. But we also can't inspect a lottery machine and predict the balls which come out either. Nobody thinks the latter is is because lottery machines also contain magic, yet so many people think that of consciousness.
Could consciousness involve extra-physical explanation? Sure. But there there is an equal amount of evidence that lottery machines do too (i.e., none).
[+] [-] BobbyJo|5 years ago|reply
When people talk about magic, they are referring to the strangeness of subjectivity, and what it is at a very fundamental level. I think a better analogy is being a Greek philosopher and trying to understand what matter is. No tool at the time can measure things in a way that would meaningfully lead them to an answer, nor did they have any theories where matter could be related to something they could study. So when we are confronted with the same situation, I think it's perfectly reasonable to assume that we, like them, are missing a massive piece of the puzzle. Calling it magic feels kind of right when it's something so large and consequential.
[+] [-] unknown|5 years ago|reply
[deleted]
[+] [-] prof-dr-ir|5 years ago|reply
Why thank you, Mr. Science Communicator. Such a tremendous insight that all I needed was a mindset to find, eh, quantum field theory?
(Apologies for the sarcasm, but - really?)
(Also: no disrespect intended to (other) science communicators.)
[+] [-] GuB-42|5 years ago|reply
She is cold, methodical, and notably critical of the search for mathematical beauty. She is pretty clear about the fact that reality is what we observe, and equations are just a tool we use to make models.
[+] [-] ukj|5 years ago|reply
Perhaps it doesn’t. Perhaps language is just a tool we, humans, use for thinking and representing our knowledge.
Mathematics is a language...
Mathematical objects need not exist anywhere else but in the Mathematician’s head.
[+] [-] seiferteric|5 years ago|reply
[+] [-] mhh__|5 years ago|reply
[+] [-] LetThereBeLight|5 years ago|reply
I don't believe that most modern physicists dispute that the equations we use are anything more than models. For example, you won't go to a seminar on microrheology and have a physicists point out in disgust that the presented derivation is "wrong" because it used Newton's second law without the relativistic component. While this is perhaps an extreme example, it is the case that we often have to ignore certain effects/make certain assumptions to make equations solvable and interpretable. If we believed that our physics equations represented some "absolute truth," then we would never allow ourselves to make these sort of assumptions in the formulas we derive.
[+] [-] el_nahual|5 years ago|reply
"a friend showed Pauli the paper of a young physicist which he suspected was not of great value but on which he wanted Pauli's views. Pauli remarked sadly, 'It is not even wrong'."
[+] [-] frongpik|5 years ago|reply
[+] [-] jl2718|5 years ago|reply
[+] [-] jl2718|5 years ago|reply
An equation can be perfectly descriptive without explaining anything, and just as easily used in a patently incorrect or at least unverifiable explanation. A new physics learner may be uncomfortable with this notion, as everything up to that point was taught as cause and effect, no difference between explanation and description. As in the example, the description could take a different form. God could use matrices. Or you could say that god prefers to minimize the lagrangian. Or you could simulate with finite element analysis and say that it is an emergent phenomenon of many points of mass all following a set of rules. Questions for each explanation abound. I think at the bottom of all of this there has to be an admission that the universe works in this particular manner because it wouldn’t exist for us any other way, and we do exist, so it must.
[+] [-] 8bitsrule|5 years ago|reply
Newton's equations are approachable, closer to human experience and comprehension. Feynman's diagrams, perhaps a step in the right direction.
True? Science is not math; it has no proofs. A 'theory' is the expression of a model that's stood the test of time - but one piece of evidence can force it to be re-built. Science forces us to search for and adapt to the new. Feynman said, "When someone says ‘science teaches such and such’, he is using the word incorrectly. Science doesn’t teach it; experience teaches it."
[+] [-] unknown|5 years ago|reply
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[+] [-] drumbaby|5 years ago|reply
Well, this article seems to be misleading drivel, to a first approximation. Why are people supposed to waste their time reading this?
[+] [-] cygx|5 years ago|reply
Well. Anecdotally, when there's open house at the physics department, the guys that will tell you how quantum mechanics and/or relativity are wrong tend to have a background in engineering.
Also note that not everyone subscribes to what the article calls the 'Gospel of Physics': Quite a few of us are well-aware that the map is not the territory...
[+] [-] hawkice|5 years ago|reply
I don't think the author is being dishonest. But that admission is extremely striking to me.
[edit: Can some admin give me guidance on how to make the point I'm clearly trying to make? I'm not sure how to make this point without being discourteous.]
[+] [-] ajkjk|5 years ago|reply
But if their problem is not being able to stomach the "just-because" explanations that every QM resigns to using to explain wtf complex conjugation has to do with reality, then I completely, totally sympathize. Learning QM consists of learning to silence your objections to the fact that none of the things you're being asked to believe make any sense.
It gets somewhat more scrutable when you deal with relativistic QM, where, at least, the terms in Schrodinger equation start to make intuitive sense (it's the first couple terms in the Taylor expansion of E psi = sqrt(p^2 + m^2) psi = m sqrt(p^2/m^2 + 1) psi = (m + 1/2 p^2/m)psi ), but then spinors enter the picture and all intuition goes out the window again.
[+] [-] whatshisface|5 years ago|reply
[+] [-] mellosouls|5 years ago|reply
But can you call a theory true if no one understands it? A century after inventing quantum mechanics, physicists still squabble over what, exactly, it tells us about reality.
I think his question is a little loaded - it's a cliché that "nobody understands it", and I'm sure there are physicists who would bridle a little at that being true.
His following claim (disputes over what it tells us) - while true - is not quite the same thing, so the argument is flawed in that regard, but not because of a problem learning maths.
[+] [-] thechao|5 years ago|reply
[+] [-] steve76|5 years ago|reply
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[+] [-] hikerclimber|5 years ago|reply
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