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With your description i would say what feynman suggests is abandoning the model altogether. Whenever i hear physicist say "we don't understand it and it doesn't

by bsaul 11y ago

With your description i would say what feynman suggests is abandoning the model altogether. Whenever i hear physicist say "we don't understand it and it doesn't matter", or speak of "spooky action at a distance", you can't say that they've built a "model" of anything that can be proved or disproved by any "better" model. They are, in fact, computing numbers, just like mayan priests, and not even try to put a "god" or a "magic number theory" behind it (as mentioned in Feynman's speech). PS : this kind of debate reminds me a bit of the debate between chomsky and norvig, with norvig saying that numbers and results are all that matters, and chomsky arguing this isn't even science.

Retra 11y ago
Capability matters, and so long as you aren't exploring avenues that could expand your capabilities, you have something more to do.
Ollinson 11y ago
You don't have to understand a model for it to bear fruit. I'm sure you could find plenty of traders on Wall Street with models of the market who would say "we don't understand and it doesn't matter" as the money flows into their account.
tagrun 11y ago
It sounds like you're confused by quantum mechanics and entanglement. We never really know "why" in that sense, that's a question best left to philosophers, and that's what doesn't matter for us --perpetually asking "why" is not productive. In general, asking questions that cannot be falsified/validated experimentally isn't useful in science, hence they don't really matter to us. A physical (or scientific) theory is such that you get more than you put into it. Newton's F=ma and inverse square law didn't just explain the motion of Venus, it explained and extremely wide range of phenomena and gave rise to thermodynamics, heat engines and fluid dynamics among many many other things. That it predicts new testable phenomena. Maxwell equations uncovered the link between magnetism, electricity and light (things that apparently have nothing to do with each other --but they do, and speed of light is related to permittivity and permeability), and eventually gave rise to special relativity. Quantum mechanics predicted --among many many other things-- anti-particles, superfluidity, superconductors. Mayan priests didn't have this. Physical theories do. "Spooky action at distance" is also an example of this, and it is something falsifiable, and its existence is experimentally confirmed. Nobody is saying we don't understand it or it doesn't matter. It is a just part of reality, and (non-relativistic) quantum mechanics. That model you're referring to is called quantum mechanics, and it has been refined by quantum field theory. You can't prove a scientific theory either way. There are physical laws that work within a certain domain. They just agree with observations. Until we observe something strange that requires a more refined theory, which however reproduces the old theory within the old domain (because it actually worked). For example, when the speed of light is much greater than any speed, you recover Newton's laws from special relativity and general relativity. When the action is large in comparison to the Planck constant, quantum mechanics turns into classical mechanics. When the mass density is small, general relativity becomes Newtonian gravity. And so on. General relativity and quantum field theory will eventually be replaced by something that will (hopefully) explain what's going on inside a black hole, what is dark matter/energy, and so on.
- bsaul 11y ago
  Ok, so i've got another question : why didn't general relativity raise the same kind of debate about its "interpretation" ? It does have its share of counter intuitive predictions ( twin paradox), new concept that are difficult to grasp ( relation between acceleration and time clock), yet i've never heard a physisict starting its general relativity course saying things like "you won't understand it, and neither do i" ( which is what feynman did in this video, and he isn't the first professor i saw doing this).
  - TheOtherHobbes 11y ago
    GR's conceptual model is fairly clear. It's completely unintuitive and hard to understand. But - so far at least - it's not open to multiple competing interpretations. QM doesn't have an agreed conceptual model at all. Stuff happens, and you can predict it statistically with a lot of accuracy. But the math doesn't reduce to a physical explanation that makes sense and everyone agrees on. No one knows if a wave function is a physical thing, or if there's some other physical process which defines the wave function, or exactly how a statistical process with spatial and temporal indeterminacy gets turned into a physical observation. These are all complete unknowns. And you can't say you understand something when you have equations that work, but no idea how or why they work. This matters because when a scientific revolution happens the conceptual model everyone uses is transformed. The math tags along behind as a proof of consistency and accuracy, but it's not the primary driver of change. If you don't have a conceptual model, you're stuck.
- effie 11y ago
  > In general, asking questions that cannot be falsified/validated experimentally isn't useful in science, hence they don't really matter to us. Does this integral diverge? What does "measurement" used in the Born rule mean? Is this algorithm used in quantum theory internally consistent? Does this result of computation violate relativity theory? Answers to these questions are not experimentally verifiable, yet they are very important, hence asking such questions is very useful in science and they do matter. > Quantum mechanics predicted --among many many other things-- anti-particles, superfluidity, superconductors. Superconductivity was first discovered in 1911, before quantum theory was even formulated, and it was not predicted. The first theory to explain superconductivity was the Ginzburg-Landau phenomenological theory and it was published in 1950. Superfluidity was discovered in 1937 by Pyotr Kapitza, again not predicted. The first theories of it were Tisza's and Landau's two-fluid models, published in 1940 and 1941. > "Spooky action at distance" is also an example of this, and it is something falsifiable, and its existence is experimentally confirmed. It is generally agreed upon that neither quantum theory nor measured correlations of light prove any action at distance. If there was such an action, we could use it for super-luminal communication.

by bsaul 11y ago

Retra 11y ago

Capability matters, and so long as you aren't exploring avenues that could expand your capabilities, you have something more to do.

Ollinson 11y ago

You don't have to understand a model for it to bear fruit. I'm sure you could find plenty of traders on Wall Street with models of the market who would say "we don't understand and it doesn't matter" as the money flows into their account.

tagrun 11y ago

It sounds like you're confused by quantum mechanics and entanglement. We never really know "why" in that sense, that's a question best left to philosophers, and that's what doesn't matter for us --perpetually asking "why" is not productive. In general, asking questions that cannot be falsified/validated experimentally isn't useful in science, hence they don't really matter to us. A physical (or scientific) theory is such that you get more than you put into it. Newton's F=ma and inverse square law didn't just explain the motion of Venus, it explained and extremely wide range of phenomena and gave rise to thermodynamics, heat engines and fluid dynamics among many many other things. That it predicts new testable phenomena. Maxwell equations uncovered the link between magnetism, electricity and light (things that apparently have nothing to do with each other --but they do, and speed of light is related to permittivity and permeability), and eventually gave rise to special relativity. Quantum mechanics predicted --among many many other things-- anti-particles, superfluidity, superconductors. Mayan priests didn't have this. Physical theories do. "Spooky action at distance" is also an example of this, and it is something falsifiable, and its existence is experimentally confirmed. Nobody is saying we don't understand it or it doesn't matter. It is a just part of reality, and (non-relativistic) quantum mechanics. That model you're referring to is called quantum mechanics, and it has been refined by quantum field theory. You can't prove a scientific theory either way. There are physical laws that work within a certain domain. They just agree with observations. Until we observe something strange that requires a more refined theory, which however reproduces the old theory within the old domain (because it actually worked). For example, when the speed of light is much greater than any speed, you recover Newton's laws from special relativity and general relativity. When the action is large in comparison to the Planck constant, quantum mechanics turns into classical mechanics. When the mass density is small, general relativity becomes Newtonian gravity. And so on. General relativity and quantum field theory will eventually be replaced by something that will (hopefully) explain what's going on inside a black hole, what is dark matter/energy, and so on.

bsaul 11y ago
Ok, so i've got another question : why didn't general relativity raise the same kind of debate about its "interpretation" ? It does have its share of counter intuitive predictions ( twin paradox), new concept that are difficult to grasp ( relation between acceleration and time clock), yet i've never heard a physisict starting its general relativity course saying things like "you won't understand it, and neither do i" ( which is what feynman did in this video, and he isn't the first professor i saw doing this).
- TheOtherHobbes 11y ago
  GR's conceptual model is fairly clear. It's completely unintuitive and hard to understand. But - so far at least - it's not open to multiple competing interpretations. QM doesn't have an agreed conceptual model at all. Stuff happens, and you can predict it statistically with a lot of accuracy. But the math doesn't reduce to a physical explanation that makes sense and everyone agrees on. No one knows if a wave function is a physical thing, or if there's some other physical process which defines the wave function, or exactly how a statistical process with spatial and temporal indeterminacy gets turned into a physical observation. These are all complete unknowns. And you can't say you understand something when you have equations that work, but no idea how or why they work. This matters because when a scientific revolution happens the conceptual model everyone uses is transformed. The math tags along behind as a proof of consistency and accuracy, but it's not the primary driver of change. If you don't have a conceptual model, you're stuck.
effie 11y ago
> In general, asking questions that cannot be falsified/validated experimentally isn't useful in science, hence they don't really matter to us. Does this integral diverge? What does "measurement" used in the Born rule mean? Is this algorithm used in quantum theory internally consistent? Does this result of computation violate relativity theory? Answers to these questions are not experimentally verifiable, yet they are very important, hence asking such questions is very useful in science and they do matter. > Quantum mechanics predicted --among many many other things-- anti-particles, superfluidity, superconductors. Superconductivity was first discovered in 1911, before quantum theory was even formulated, and it was not predicted. The first theory to explain superconductivity was the Ginzburg-Landau phenomenological theory and it was published in 1950. Superfluidity was discovered in 1937 by Pyotr Kapitza, again not predicted. The first theories of it were Tisza's and Landau's two-fluid models, published in 1940 and 1941. > "Spooky action at distance" is also an example of this, and it is something falsifiable, and its existence is experimentally confirmed. It is generally agreed upon that neither quantum theory nor measured correlations of light prove any action at distance. If there was such an action, we could use it for super-luminal communication.