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Why the foundations of physics have not progressed for 40 years

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Re: Why the foundations of physics have not progressed for 40 years

#231

Post by ProblemFactory »

cletus wrote: post #164

Does anyone else feel like the abstractions and models in physics have gone passed the point where the casual outsider (even a technically and scientifically minded one) can no longer intuitively understand it? Because that's how I feel. There are so many things I just don't understand now like: 1. I originally thought the Heisenberg Uncertainty principle was a natural consequence of using particles (photos) for meas…

> Or am I just a lemur trying to figure out how an airplane works?

Unfortunately yes, all of us are.

This is not a problem with physics or abstractions. It's a problem with our intuition. Our intuition is based on evolution and life experience, which is all formed based on mostly solid objects from 1cm to 100m moving at 1m/s to 100m/s.

The universe however does not care what meatbags can experience with our senses. It doesn't mean that our complex math abstractions are necessarily correct - but they are more correct than casual intuition. You can train that intuition with enough work with the maths.

For example, you can map most of basic electricity to water flow and pressure, and some electromagnetic waves to waves in water - but you need to make a small jump to abstraction to combine both, and a large jump to get a gut feeling for special relativity to "feel right".

The crazy part is really that mathematical abstractions exist for all these things at all. There seems to be no natural reason that physics should be describable by small elegant formulas at all, let alone our experience of throwing rocks into a pond. Why isn't particle physics as messy as organic chemistry?

Re: Why the foundations of physics have not progressed for 40 years

#232

Post by abecedarius »

whatshisface wrote: post #194
gus_massa wrote: post #148

Earlier quoted context omitted.

These theories have a very precise mathematical formulation and very weird unintuitive consequences. If you try to teach them without math, you only keep the weird unintuitive part and it's more unintelligible. For quantum mechanics you have to know eigenvalues and eigenvectors. This is studies in the first years of the university in a technical career. I'm not sure if it can be teach much earlier. For Special Relati…

Linear algebra (with diagonalization not just using gauss-jordan) could be pushed back to highschool for motivated students, and is in some countries. The coordinate system aspect of special relativity (the origin of time dilation and most of its "weird effects") only requires algebra. General relativity requires the full mechanisms of differential geometry but advances in things like differential forms are pushing t…

Turtle Geometry gets as far as motion in curved spacetime using code in Logo. Dunno how many high schoolers have ever learned from it, but it's there. (It includes a nice concrete intro to vector algebra earlier, too.)

Re quantum mechanics without many prerequisites, I'm a fan of Feynman's book QED.

Re: Why the foundations of physics have not progressed for 40 years

#233

Post by paganel »

Anon84 wrote: post #112
paganel wrote: post #33

Earlier quoted context omitted.

From an outsider's point of view (i.e. mine) it looks like physics has become too enamored with mathematics, "thinking" that reality can be totally described by mathematics. Which brings us to one of the author's point of views, the fact that physicists (and I guess most scientists) nowadays dismiss things like philosophy of science or epistemology, they just continue head-on on their "quest for knowledge" not realiz…

If the past is any guide, whenever reality isn’t adequately described by mathematics we just come up with new mathematics.

I may be in the wrong here, but afaik mathematics has not "re-invented" itself after WW2, to take it a step further, I fail to see how we're doing different mathematics compared to what Newton and Leibniz have put on the table.

Even if we look at the "greatest" post-WW2 maths result, Fermat's Theory, I don't see any new reality-related insights that it has brought us, and I'll go another step further and I say that even if we were to someday prove the Riemann hypothesis I don't see how it would fundamentally bring new insights regarding "reality"/the physical world.

If anything, I dare say that in a certain way maths has tainted the physical world for us, has made us believe that in the same way in which mathematics is "homogeneous" then the physical world is too, if maths has numbers and "units" and if (1002 - 1000) = (2002 - 2000) then it also means that in the physical world we have homogenous "stuff".

This is why physics has started using mystical-like language like "elementary particles" which are seen as the "foundation of the physical world", with the implicit premise (if I'm wrong here, please correct me) that given a certain "elementary particle" (let's say a boson) then the boson close to it or the boson situated at the other "side" of the Universe are pretty much the same thing, almost identical, the same way as the mathematical difference I mentioned above is the same, or how two parallel lines are "the same".

Basically almost all the theoretical physicists have become Platonists by embracing mathematics no-questions-asked, when in fact they should have remained closer to Hume. And when reality hits them in the face pretty hard they resort to even more mysticism by "inventing" concepts like dark energy and the like.

Later edit: I see that that "homogenous reality" theory even has a name, Cosmological principle [1], and as a close-enough Hume follower Karl Popper was quick to dismiss it. By reading it you have to wonder what those physicists had in mind when they wrote it down:

> Although the universe is inhomogeneous at smaller scales, it is statistically homogeneous on scales larger than 250 million light years.

like, why 250 million is ok and 240 million light years is not ok? To say nothing of the fact that the "infinitely small" (the mystical-like elementary particles I mentioned above) are ignored completely from this discussion, they're also probably seen as "statistically the same". As I said, this "statistical sameness" has made us believe that more than half of the Universe we know of (68%, to quote Wikipedia) is made out of the mother of all mystical thingies, "dark energy".

[1] https://en.wikipedia.org/wiki/Cosmological_principle

Re: Why the foundations of physics have not progressed for 40 years

#234

Post by effie »

cletus wrote: post #164

Does anyone else feel like the abstractions and models in physics have gone passed the point where the casual outsider (even a technically and scientifically minded one) can no longer intuitively understand it? Because that's how I feel. There are so many things I just don't understand now like: 1. I originally thought the Heisenberg Uncertainty principle was a natural consequence of using particles (photos) for meas…

Yes. First, intuition depends on your experience. If you never studied physics, most things will be nonintuitive (heavy bodies don't fall faster than light ones? really?)

Second, modern 20th century physics education (courses, textbooks) suffered sustained corruption of methodology by scientific authorities, where the quest for understanding was renounced in favor of "modelling" and "prediction" (e.g. authors of orthodox quantum theory and their less bright pupils perpetuating that attitude) and later by institutionalized system of university research which propels tweaking and applying old ideas to detriment of trying new ones or questioning past ideas that are too ingrained.

This leads to a large portion of theoretical physics publications being more and more about complex calculations where most applicators do not even try to understand "what is going on", they just assume the same quantum methodology with some tweaks (i.e. different configuration spaces, more dimensions, different Lagrangians, new fields that fix problems of the previous ones, tricks with removing some ugly series terms etc).

Sometimes these tweaks get fancy names (superstrings, loops, dark matter) but they are really an additional concept that needs to be put in to save the edifice from those radicals who would like to try actually new and incompatible ideas.

When you study 20th century physics yourself from original sources, you'll find the stuff taught currently actually has highly varying degree of credibility. Some stuff is rock solid, such as relativity, molecular theory and chemistry, nuclear physics and solid state theory, and some stuff is ... well, more unfinished and less credible - such as standard model, force unification, quantum gravity, dark matter, etc.).

If you want to get some solid ground on which to build intuition, start with the rock-solid physics as known till 1905, then after that makes sense, learn about its problems (explanation of emission spectra, inconsistency of EM theory with Newtonian mechanics), then after that take a deep breath and read original papers on quantum theory and particle/nuclear physics.

This will take years to understand. The later theoretical stuff around Standard Model details (lepton generations, stability of particles, unification of gravity and QFT) is a decades old project that nobody knows how to finish. It is stuck for now, and has little relevance for understanding those previous things.

Re: Why the foundations of physics have not progressed for 40 years

#235

Post by brutt »

pixl97 wrote: post #190
ibeckermayer wrote: post #157

Earlier quoted context omitted.

Fair point, so then let me reframe the inconsistency as: there’s a phenomena that appears exhibits properties of both a particle and a wave but it can’t be both. So what is it? And the criticism of mainstream thought in physics would be: its wrongfully dismissive of my question, and ignoring the important job of looking for the answer.

How about "it's a thing that does not have an analog at the macro scale in which humans exist, therefore any explanation that does not use terminology from our daily lives will be unsatisfactory"

It has analog at macro-scale: it's a particle surrounded by a wave. Double split experiment is reproduced in macro almost decade ago!

Re: Why the foundations of physics have not progressed for 40 years

#236

Post by chopin »

vkou wrote: post #174
cletus wrote: post #164

Does anyone else feel like the abstractions and models in physics have gone passed the point where the casual outsider (even a technically and scientifically minded one) can no longer intuitively understand it? Because that's how I feel. There are so many things I just don't understand now like: 1. I originally thought the Heisenberg Uncertainty principle was a natural consequence of using particles (photos) for meas…

The casual observer hasn't been able to understand the forefront of physics for a very long time. Maxwell's equations have been known for 150 years[1], but the average high school physics student hasn't the foggiest idea of what a differential equation is. At best, they have a vague understanding that electricity and magnetism are more-or-less interchangeable. Once you get into invisible forces acting across very sma…

A great deal of (19th century) thermodynamics has its roots in the desire to engineer better steam engines. Entropy as an example has been introduced as an abstract concept to get to engines with better efficiency. Even when statistical thermodynamics was suggested (which makes of a less abstract and more intuitive understanding of thermodynamics) it was strongly opposed by many of the pundits at that time.

Re: Why the foundations of physics have not progressed for 40 years

#237

Post by davrosthedalek »

moralsupply wrote: post #20

Perhaps we need some new mathematics, not new physics

Indeed, that is a big impediment in many disciplines. Non-perturbative QCD (i.e. what describes the mass around you) can not be calculated analytically with a controlled level of precision. The best we can do is lattice QCD, i.e. the brute force approach. That's a big difference to QED, where we know how to find better and better approximations in a systematic way.

In other words, QCD, like many complex systems, shows emergent behavior not easy to predict from the theory input (couplings, masses). A better mathematical framework to attack these kind of problems would be a substantial jump forward.

Re: Why the foundations of physics have not progressed for 40 years

#239

Post by tabtab »

cletus wrote: post #164

Does anyone else feel like the abstractions and models in physics have gone passed the point where the casual outsider (even a technically and scientifically minded one) can no longer intuitively understand it? Because that's how I feel. There are so many things I just don't understand now like: 1. I originally thought the Heisenberg Uncertainty principle was a natural consequence of using particles (photos) for meas…

Re: "Does anyone else feel like the abstractions and models in physics have gone passed the point where the casual outsider (even a technically and scientifically minded one) can no longer intuitively understand it?"

That's how I feel when using Twitter Bootstrap compared to the WYSIWYG days of VB-classic and Delphi. Like Quantum Physics, getting Bootstrap right relies on probability and killing of cats, or at least hair follicles. (Our shop probably needs a dedicated UI coder, but office politics won't allow it.)

Re: Why the foundations of physics have not progressed for 40 years

#240

Post by nitrogen »

cletus wrote: post #164

Does anyone else feel like the abstractions and models in physics have gone passed the point where the casual outsider (even a technically and scientifically minded one) can no longer intuitively understand it? Because that's how I feel. There are so many things I just don't understand now like: 1. I originally thought the Heisenberg Uncertainty principle was a natural consequence of using particles (photos) for meas…

As a layperson I recommend watching the PBS Spacetime channel on YouTube: https://www.youtube.com/channel/UC7_gcs09iThXybpVgjHZ_7g
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