Why the foundations of physics have not progressed for 40 years • Hacker News Board

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

#191

Post by shuspect » Mon, Jan 13, 2020, 7:44 PM UTC

gus_massa wrote: post #148

j1vms wrote: post #137

The role of this "era" may be in reformulating quantum physics and, separately, general relativity in new ways that make the ideas more accessible to more people, and earlier in their lives. The goal could be to make of modern physics... the new classical physics. That is, we start to let go the crutches we still teach because it is thought that day-to-day life is more readily explained by Newtonian physics. We are n…

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…

We can keep math, but switch to better theories, with plausible explanations.

A kind of Pilot Wave can explain quantum weirdness to layman people with ease.

We can ditch theory relativity and calculate speeds relatively to CMB, which is much easier to understand.

We can ditch Big Bang theory and, instead, accept that light is not immortal, because it ages with time. IMHO, Dipole Repeller and Shapley Attractor are much more attractive and easier to explain than Big Bang.

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

#192

Post by conception » Mon, Jan 13, 2020, 7:46 PM UTC

mfer wrote: post #167

ISL wrote: post #86

I strongly disagree that the foundations of physics have not progressed for 40 years. We have been looking really hard for answers to persistent questions. While we have not found affirmative answers, physicists have systematically ruled out option after option after option. We have not yet discovered a unified-theory-of-everything, but we know a whole lot more about what that theory is not . Furthermore, the past 40…

> I strongly disagree that the foundations of physics have not progressed for 40 years. I think, we are getting a peak at the politics of the practice of science when you look at the article and comments, like this ones parent. A bunch of this is about the unobserved. The theoretical rather than then experimentally observed (think scientific method). Whose theories get the funding to be looked into? Whose ideas are p…

I think what people miss about the industry of Science is that, logically, if a paper says "A=Foo" then we'd expect it to be true. And if another comes out that says, "A=Bar" then it's confusing, are both wrong, are both right.

But instead, the way it works is a consensus is built. Researcher Bob - "We see that A=Foo." Researcher Sally -"Well, I see that A=Bar." Researcher Timmy - "Well, I see that A=Far." Researcher Kimmy - "Well, I see it as A=Fbar." Community over time - "Now the community has seen that A=Fbar is consistently correct and can be relied upon and used." 20 years pass... Researcher Jeff - "Well, I see that Ab=Fbar actually." Community - "That's bullshit." Researcher Betty - "Well, actually I see that too. But I see Ab=FbarC". etc etc

Since we don't know what we don't know, it isn't really a "We're done!" situation for someone to get 100% correct, it's a process of evolution in knowledge.

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

#193

Post by orbifold » Mon, Jan 13, 2020, 7:48 PM UTC

mellosouls wrote: post #18

cjfd wrote: post #7

Actually, string theory arose as a way of doing exactly what this person requests. It was noticed that quantum field theory and gravity do not go together, so it was attempted to do something about this. So, it did not really work out? Well, you know the thing with this kind science is that it is unknowable beforehand what you are or are not going to find.

The claim of sceptics along these lines is that string theory has produced nothing in 50 years and some string theorists appear to be in denial of that.

In science as in pretty much any other discipline you should always weigh someones opinion by their believability / credibility. The credibility of someones opinion on something is a function of their knowledge / experience of the subject and things related to it. To first approximation most sceptics have close to zero credibility making claims about string theory, as they have not produced scientific output remotely comparable to proponents of string theory. This is simply because people like Witten tower far above most other working theoretical physicists.

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

#194

Post by whatshisface » Mon, Jan 13, 2020, 7:52 PM UTC

gus_massa wrote: post #148

j1vms wrote: post #137

The role of this "era" may be in reformulating quantum physics and, separately, general relativity in new ways that make the ideas more accessible to more people, and earlier in their lives. The goal could be to make of modern physics... the new classical physics. That is, we start to let go the crutches we still teach because it is thought that day-to-day life is more readily explained by Newtonian physics. We are n…

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 this back to the undergraduate level. Overall I would say that it could be done but you would have to leave the unmotivated students behind.

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

#195

Post by ibeckermayer » Mon, Jan 13, 2020, 7:53 PM UTC

peteradio wrote: post #172

phkahler wrote: post #158

Earlier quoted context omitted.

>> A photon isn't both a particle and a wave. It's something else that happens to share some features with both. But physicists have given up on figuring out what it IS. They have decided that having math that can predict the outcome of experiments is enough. They're not wrong, but it feels rather unsatisfying. IMHO there have been a couple avenues worth exploring that are being largely ignored.

Its not satisfying because its not intuitive. Its not intuitive because our billion years of evolution never exposed use to such experiences to observe. If we limit ourselves to only whats intuitive it will be necessarily limiting to our ability to make new discoveries.

Let's grant the point that there may be some phenomena in the universe the human mind is not equipped to understand (which is a nuanced position but we can ignore those nuances for now):

Why should we assume that the contradictions in contemporary theories are of this special, inexplicable type? Every era has contradictions, before they are resolved... But they'll only ever be resolved if people are trying to resolve them, meaning that they haven't resigned themselves to the idea that our minds haven't been gifted with the capacity to make sense of our experience.

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

#196

Post by brutt » Mon, Jan 13, 2020, 7:54 PM UTC

nablaoperator wrote: post #185

brutt wrote: post #114

Earlier quoted context omitted.

I received hundred of downvotes just asking questions here (like "Why we have right hand rule for current? What must be changed in properties of Nature to make it left hand rule?"). It's sad that I need to use throwaway accounts to talk about physics.

Try not to be discouraged, it's okay to talk about physics. But try to use the right language for it - mathematics. In online forums, physical ideas or questions are often described in words, which is subject to so much imagination that it can be considered philosophy, but not physics. It's almost pointless to talk without mathematical support. Words are words and have no special meaning. In the example above: A bett…

So what need to be changed in properties of Nature to switch EM with Right Hand Rule into EM with Left Hand Rule? Can you explain this using a formula?

Where we can expect to see EM with LHR? Can we see it in our Laniakea? Or at opposite side of Shapley Attractor - Dipole Repeller? Or at perpendicular one? Do we have void between RHR and LHR? Can we cross it?

What is nature of EM? Is it because of nonlinear trajectory of motion of our galaxy from Dipole Repeller to Shapley Attractor? Or it because of non-linear motion of our galaxy within Laniakea? Or something else?

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

#197

Post by whatshisface » Mon, Jan 13, 2020, 7:56 PM UTC

phkahler wrote: post #160

j1vms wrote: post #137

The role of this "era" may be in reformulating quantum physics and, separately, general relativity in new ways that make the ideas more accessible to more people, and earlier in their lives. The goal could be to make of modern physics... the new classical physics. That is, we start to let go the crutches we still teach because it is thought that day-to-day life is more readily explained by Newtonian physics. We are n…

One problem is that physicists are not interested in lowering the bar to understanding advanced theories. Some say it's all fairly simple once you spend a decade learning some very advanced math. The art of teaching is in making the material more accessible, and at that I dont think much progress has been made.

>physicists are not interested in lowering the bar to understanding advanced theories

That is not true, geometric algebra is an example of a recent pedagogic improvement that is getting a lot of attention. The problem is that physics will never be easy enough for someone who is not prepared to think deeply, because it is one of the few areas where truly new ideas can be found. Virtually every area of learning involves repackaging concepts we have all known from childhood (people's motivations, stories, colors, that kind of thing) in specific ways. Major exceptions are physical tasks like learning to sew or play an insturment, and "esoteric" subjects like math and physics. In all of those cases you cannot learn by casually reading because the neurons in your brain are simply not prepared for it.

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

#198

Post by rpz » Mon, Jan 13, 2020, 7:59 PM UTC

akubera wrote: post #140

rpz wrote: post #61

Earlier quoted context omitted.

Down votes? Care to explain? I'm just trying to learn here :)

Didn't downvote, but they probably came because you asked a very tangential question to the subject. I'll try to answer it: I think you just want to move units around so h (Planck's constant) has units of Joules instead of Joule-seconds. While this works mathematically, it doesn't really make sense physically, where we care about the energy of a photon because that's the value that is conserved (along with momentum,…

Consider it this way. Suppose we all agreed to never use numerical values in the units section of an equation... then in this case we'd need a symbol for cycles in cycles per second aka Hz.

If we leaves Planck's constant as is in E=h(cycle/second), then the units would end up as Joulecycle... odd right?

That's what brought me to writing the formula as

E=utf

I guess it should really be

Delta E=u(delta t)f where u is in joules t is (seconds per cycle) and f is (cycles per second)

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

#199

Post by deng » Mon, Jan 13, 2020, 7:59 PM UTC

ISL wrote: post #86

I strongly disagree that the foundations of physics have not progressed for 40 years. We have been looking really hard for answers to persistent questions. While we have not found affirmative answers, physicists have systematically ruled out option after option after option. We have not yet discovered a unified-theory-of-everything, but we know a whole lot more about what that theory is not . Furthermore, the past 40…

While I mostly agree with you, this is not really a counterpoint to Hossenfelder's position. There is no denying that experimental physics has produced great results in the last 40 years, but the theories underlying these results have remained unchanged during that time.

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

#200

Post by jfengel » Mon, Jan 13, 2020, 8:03 PM UTC

nonbel wrote: post #106

kosievdmerwe wrote: post #97

Earlier quoted context omitted.

Sounds more like a formula that needs more terms. Compare the classical physics formula for momentum, p=mv, vs relativistic formula, p=γmv. γ is almost 1 for most low velocities, it only starts jumping up to infinity when we get close to c. The point being that the classical formula is pretty good in it's zone of low velocities, but as soon as you get too far out of the implicit term's "constraints" the formula break…

Adding more terms sounds like more overfitting.

It sounds like that only because scientists reformulate their models in terms that people are familiar with. Actual physicists don't work in terms of the gamma correction factor; they work in tensor fields that don't look anything like conventional arithmetic.

But they can pare all that down to something expressed in terms people are familiar with. And that has the bonus purpose of helping them understand why the familiar terms were familiar: the "correction factor" is small under circumstances we encounter, and only becomes large under circumstances we rarely do.

If that intrigues somebody enough to learn the actual physics, they'll encounter a completely different and more-encompassing formulation which looks not at all like overfitting. One that turns out to be more elegant, in fact, cramming more information into less notation. But it's information nobody needs until they're doing fairly advanced physics, so we're not going to be teaching it in elementary school any time soon.