Comment by blackhaj7
2 years ago
I have no doubt quantum physicists know what they are talking about but when I read stuff like:
“changes its appearance depending on how it is probed"
"you can’t even imagine how complicated it is"
"the proton contains traces of particles called charm quarks that are heavier than the proton itself"
I always think it is the kind of excuse a schoolkid would give their teachers for their calculations being wrong
> I have no doubt quantum physicists know what they are talking about but...I always think it is the kind of excuse a schoolkid would give their teachers for their calculations being wrong.
Just to emphasize how extreme this dichotomy is, not only is quantum mechanics correct (in that it's a predictive model), it's the most correct physical theory humans have ever devised in that the measurements there have more significant figures than anything else.
It's interesting that semiconductor engineers have to directly wrestle with the magic that's quantum tunneling. This theory is really not just a theory.
In some devices it's something they have to fight against. In others, like SSDs, it's the feature that makes them work! It's not just a theory and it's not just another flaw that we've got to work around, we've taken it from a theory and turned it into useful technology.
You mean it's not just a hypothesis.
I would really, really expect users of this site to know the difference.
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The other famous example is PET scanners, which actually use a form of antimatter: positrons (the antimatter counterpart of electrons).
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We used fire in our daily lives even before organic chemistry existed.
So many significant digits includes a level of self-consistency of the model, since we are assuming the model to some degree in order to measure it. Though in this case, it's not the calculations that are wrong, but the model, we hope is wrong. That is, a new perspective and a new way of thinking about things may reveal more. Of course, we are always fighting against the irreducible complexity camp. However, the fundamental lack of cohesion between quantum and relativistic theories demonstrates there is at least one big thing we are still doing wrong.
> So many significant digits includes a level of self-consistency of the model
No, that's incorrect. The specific measurement -the most accurate scientific prediction humans have ever made, the anomalous magnetic moment- is only to 1 in 10 trillion. The magnetic moment (think moment of inertia) is the ratio of force from the magnetic field to the mass of the electron. You put an electron into a magnetic field, and it'll turn to face the field at a certain speed. If you stick the electron in a vacuum, it overshoots (because of rotational momentum) and ends up wobbling back and forth at a specific frequency. That's how MRIs work; they make a big magnetic field (stronger on one end) and then measure how many electrons are wobbling in different areas, since the electrons in high-strength fields wobble faster.
Specifically, you expect the wobble to get ~2.8025 GHz (similar to a microwave oven) faster for every 1000 gauss (please, no jokes about teslas). It's very convenient to measure a difference in frequency, since you can just measure the drift over time. Because that frequency is relatively high it takes about 30 minutes for the frequency to drift off by a half-cycle and totally cancel out your reference.
And it's super easy to get a reference frequency, too. It's just the charge of an electron divided by 2x the mass of an electron. Did you do this experiment in physics class? https://www.youtube.com/watch?v=Kcn2VgBNJjg
Then you measured the charge/mass ratio of an electron. A clock that's accurate to 1 in 10 trillion is also not a big deal, although unless you have an oscilloscope in your house its probably more accurate than any clock you own. Still, you can buy a better Phase Locked Loop for a couple bucks.
If you just wanted to measure the difference, you don't need that much precision, though. The correction from quantum mechanics is pretty large, relatively speaking: ~0.16%. Even the next several digits are super easy, and it's only those last ones that you really need to bust out the liquid helium.
Lawrence and Livingston made the first cyclotron out of literal junk: https://upload.wikimedia.org/wikipedia/commons/6/61/4-inch-c...
And it really doesn't take much more than junk to get to that 0.16% accuracy that lets you see that a classical prediction of the electron is just VERY wrong. But if you listen to those wizards with the bongos, suddenly they're really, really right about what that difference is: https://en.wikipedia.org/wiki/Vertex_function
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That’s awesome to hear.
I totally back the scientists and wish I could understand it better but I always like to have a chuckle that the crazy sounding parts are just the scientists making up stuff
Just because it’s quantitatively accurate doesn’t mean it’s “true”. Like a fun fact I like is the geocentrism was extremely accurate in terms of astronomical predictions when heliocentricism came about (it was actually more accurate for a while).
How do you define 'true'?
If two theories are working very well with no experiment available to indicate right vs. wrong for them, Occam's Razor would be all we would have to make a choice. That however does not really make one of them truer than the other.
Popular science writers on this stuff tend to be in a similar position to the teachers. The real physics is described in complex mathematics and doesn't translate to simple English very well.
It's definitely not wrong, but maybe more akin to the earth-centric view of the universe and the insane patterns that planets would trace in the sky. Just in this case we don't have another object like the sun to use to pivot our models. Maybe there are superstructures hidden that we could access if we could look into objects outside space-time, but until then space-time reduction is what we have right now other than guesswork (https://en.m.wikipedia.org/wiki/Amplituhedron)
Quantum mechanics is a religion with mathematics instead of just holy texts.
Several studies have been done into whether practicing theoretical physicists using QM in their everyday work agree on the most basic tenets of the field.
Spoiler: they disagree on every aspect while simultaneously assuming that their opinions are correct and that everyone else agrees with them.
That’s how religions work, not how science does. Factions instead of consensus. Branches splitting off all the time and never supplanting the majority. Orthodoxy (Copenhagen). Shunning anyone that steps out of line (Everett). Refusing to question the holy texts, etc…
Another key symptom is requiring members to prove their devotion by saying and doing things that are obvious nonsense. Bending their common sense to the will of the group. In Christianity this is the trinity: one God that is three. In QM it’s the wave-particle duality, which is just nonsense. You can’t have a point with a kilometre long wavelength!! Yet, we are to believe (on faith!) that radio waves are made of photons.
Turns out that magical thinking and religiosity is the essential nature of humans, especially in large groups.
Whenever there is insufficient evidence to bring everyone into line, the line splinters into warring factions where the best argument each tribe has is: “my tribal leader said so!”
All of the disagreements in QM are metaphysical: what is measurement, how does a wavefunction collapse, what is reality, etc. Everyone agrees on the math that leads to predictions (which have been matched by observation to an almost perfect degree). And I'd imagine that just about everyone also agrees that it's incredibly unintuitive. But the math works.
That’s not really true, there may be ways to experimentally distinguish between those disagreements
I want whatever you're smoking, because it's the best predictive theory we have, and is constantly tested and proven. Only the why is in question, but the math absolutely works.
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I mean semiconductor engineers have to deal with quantum effects when designing chips. Its not like it doesn't effect the real world, we do interact with parts of it when things get really small.
An actual semiconductor engineer that works at ASML has uploaded a whole series of videos that debunk the existence of photons in free space[1]. https://www.youtube.com/shorts/V6G8ZZmeJzc
Quantum Mechanics is a set of mathematical tricks, shortcuts for numerical computation, that is all. People have become so enamored with the results of those computations that they've blithely ignored the limited scope of these shortcuts. You've found a nailgun, it's better than a hammer. That doesn't mean everything is a nail now.
[1] Essentially, "particles" like photons are a short-hand terminology and a matching set of mathematical shortcuts for the behaviour of waves in a potential well (or any cavity). It doesn't make any sense outside of that scenario, such as light traversing empty space. All of that behaviour is perfectly predictable with ordinary wave mechanics. No quantum woodoo is required.
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