3 ms·

Feynman's QED talks pretty extensively about this as well. An intuitive mental model that humans can picture in their heads is a nice to have, not a requirement

by qqtt 4y ago

Feynman's QED talks pretty extensively about this as well. An intuitive mental model that humans can picture in their heads is a nice to have, not a requirement. Understanding how a system "really works" is also not really a goal of physics - the science is about predicting physical phenomena - and we generally choose whatever is the simplest equation we have currently available that does that. If you want to define the bar for explaining how a "system really works" as being able to give you an intuitive human-centric mental model you can fully understand and capture in your head - well, you are moving the goal posts over what physics really is and quantum physics has already left you far behind.

throwaway81523 4y ago
> Understanding how a system "really works" is also not really a goal of physics - the science is about predicting physical phenomena I have to point out the above is a rather strong and debatable claim. I think most people who study science do want to understand how things really work. Even if we accept that physicists only want to predict phenomena as opposed to understanding them, the same can't be said of other sciences (let's say astronomy, or molecular genetics). Mathematicians seek almost exclusively to understand things rather than predict them. So the claim attributes a certain lack of curiosity specifically to physicists, that doesn't apply to biologists, mathematicians, etc. To me, that makes it even more peculiar. So I'm skeptical.
- qqtt 4y ago
  I put "really works" in quotes because the definition of how to get to the bottom of how something "really works" is up for debate itself. The original context for claiming something like path integrals can't be how the system "really works" because it is some combination of being too complex, lacking an intuitive mental model for how to conceptualize it, and invoking things that seem extraneous to the person making the claim (possible paths that aren't necessarily realized). I would agree that physicists have the same, or perhaps even more, curiosity regarding discovery as other fields (partly why they are drawn to understanding the nature of the existence/universe itself) - but there is certainly an error with this narrow definition of "this can't be how it really works because X" is simply wrong - we choose the simplest explanation which meets the scientific criteria for the time, and up until something new is discovered - that is de facto how the system "really works". Ultimately people have this assumption from classical mechanics that everything can neatly fit into intuitive thought experiments to understand the nature of reality, but quantum mechanics has not followed the same human-centric intuitive modeling. Does it mean we haven't figured out how the system "really works"? Ultimately, it's a philosophical question, not question directly related to physics which is showing the way through predictable repeatable science.
  - GoblinSlayer 4y ago
    You mean you don't understand when you don't know something? If you had no problem reasoning about quantum physics, you wouldn't say it's a philosophical question.
  - throwaway81523 4y ago
    The path integral formulation doesn't sound that counterintuitive to me, though I don't know anything about it in terms of actually computing with it. Aren't there similar integrals in statistical thermodynamics, where what is "really going on" is random motion of molecules and the math has to consider every possible path, though in Euclidean space? I'd like to understand this stuff better someday. The "really going on" of quantum mechanics is perhaps more mysterious, but that doesn't mean physicists don't want to find it.

by qqtt 4y ago

throwaway81523 4y ago

> Understanding how a system "really works" is also not really a goal of physics - the science is about predicting physical phenomena I have to point out the above is a rather strong and debatable claim. I think most people who study science do want to understand how things really work. Even if we accept that physicists only want to predict phenomena as opposed to understanding them, the same can't be said of other sciences (let's say astronomy, or molecular genetics). Mathematicians seek almost exclusively to understand things rather than predict them. So the claim attributes a certain lack of curiosity specifically to physicists, that doesn't apply to biologists, mathematicians, etc. To me, that makes it even more peculiar. So I'm skeptical.

qqtt 4y ago
I put "really works" in quotes because the definition of how to get to the bottom of how something "really works" is up for debate itself. The original context for claiming something like path integrals can't be how the system "really works" because it is some combination of being too complex, lacking an intuitive mental model for how to conceptualize it, and invoking things that seem extraneous to the person making the claim (possible paths that aren't necessarily realized). I would agree that physicists have the same, or perhaps even more, curiosity regarding discovery as other fields (partly why they are drawn to understanding the nature of the existence/universe itself) - but there is certainly an error with this narrow definition of "this can't be how it really works because X" is simply wrong - we choose the simplest explanation which meets the scientific criteria for the time, and up until something new is discovered - that is de facto how the system "really works". Ultimately people have this assumption from classical mechanics that everything can neatly fit into intuitive thought experiments to understand the nature of reality, but quantum mechanics has not followed the same human-centric intuitive modeling. Does it mean we haven't figured out how the system "really works"? Ultimately, it's a philosophical question, not question directly related to physics which is showing the way through predictable repeatable science.
- GoblinSlayer 4y ago
  You mean you don't understand when you don't know something? If you had no problem reasoning about quantum physics, you wouldn't say it's a philosophical question.
- throwaway81523 4y ago
  The path integral formulation doesn't sound that counterintuitive to me, though I don't know anything about it in terms of actually computing with it. Aren't there similar integrals in statistical thermodynamics, where what is "really going on" is random motion of molecules and the math has to consider every possible path, though in Euclidean space? I'd like to understand this stuff better someday. The "really going on" of quantum mechanics is perhaps more mysterious, but that doesn't mean physicists don't want to find it.