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Is the Schrödinger Equation True?

scientificamerican.com

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Re: Is the Schrödinger Equation True?

#101

Post by KirillPanov »

lmm wrote: post #65

The Schroedinger Equation is the most true thing I've ever encountered. It is clear, simple, obvious in its correctness; the greatest piece of physics since Maxwell. Once you've understood it it becomes almost impossible to imagine that the universe could possibly work any other way. (Contrary to this article's claim, the equation describes the behaviour of Helium atoms perfectly well; it's a failure of our imaginati…

> Did they really expect that the behaviour of the very small would be exactly like that of everyday macroscopic objects?

I expect a theory predicting otherwise to bear the burden of demarcating exactly where the boundary between "macroscopic" and "weird not-macroscopic" lies (waving your hands and mumbling "thermodynamics" does not count). I expect that such a theory's proponents should be absolutely burning with interest in probing, studying and understanding what goes on at this peculiarly discontinuous boundary in Nature.

Those two things haven't happened, which is kind of sad.

Quantum Mechanics predicts the results of experiments better than anything else. If "predicts experimental results" is the only thing you care about, then Bohr was right, QM is complete, and there's nothing more to be written in that book.

Re: Is the Schrödinger Equation True?

#102

Post by tasty_freeze »

> The “laws” of physics, Wigner adds, have little or nothing to say about biology, and especially about consciousness, the most baffling of all biological phenomena.

Starting with the laws of physics, no, we cannot in practice calculate a consciousness. But we also can't inspect a lottery machine and predict the balls which come out either. Nobody thinks the latter is is because lottery machines also contain magic, yet so many people think that of consciousness.

Could consciousness involve extra-physical explanation? Sure. But there there is an equal amount of evidence that lottery machines do too (i.e., none).

Re: Is the Schrödinger Equation True?

#103

Post by postalrat »

lmm wrote: post #100
frongpik wrote: post #76

Earlier quoted context omitted.

What's natural about SE? From my limited understanding, SE tells us that all particles in the world are interconnected in a peculiar way by a "energy field" of some sort.

It's a very simple equation and it's kind of the "square root of" the basic wave equation (d^2x/dt^2 = -k x). So it's the most obvious way to have an equation that can describe a space where waves are pervasive but there are also non-wave things, which is what reality is.

That's pretty vague. Something so obvious, correct, simple and clear should have a more straight forward explanation.

Re: Is the Schrödinger Equation True?

#104

Post by BobbyJo »

tasty_freeze wrote: post #102

> The “laws” of physics, Wigner adds, have little or nothing to say about biology, and especially about consciousness, the most baffling of all biological phenomena. Starting with the laws of physics, no, we cannot in practice calculate a consciousness. But we also can't inspect a lottery machine and predict the balls which come out either. Nobody thinks the latter is is because lottery machines also contain magic, y…

I dislike this comparison. The reason we can't explain consciousness isn't because it complex or because there are too many variables for us to track and predict, as in the case of the lottery machine, but because we haven't decided what we mean when we say 'conciousness'. Pretty much any component of consciousness one may think of can be explained in isolation as a simple material system. Self-reflection, continuity, response to stimuli, etc.

When people talk about magic, they are referring to the strangeness of subjectivity, and what it is at a very fundamental level. I think a better analogy is being a Greek philosopher and trying to understand what matter is. No tool at the time can measure things in a way that would meaningfully lead them to an answer, nor did they have any theories where matter could be related to something they could study. So when we are confronted with the same situation, I think it's perfectly reasonable to assume that we, like them, are missing a massive piece of the puzzle. Calling it magic feels kind of right when it's something so large and consequential.

Re: Is the Schrödinger Equation True?

#105

Post by kirrent »

KirillPanov wrote: post #101
lmm wrote: post #65

The Schroedinger Equation is the most true thing I've ever encountered. It is clear, simple, obvious in its correctness; the greatest piece of physics since Maxwell. Once you've understood it it becomes almost impossible to imagine that the universe could possibly work any other way. (Contrary to this article's claim, the equation describes the behaviour of Helium atoms perfectly well; it's a failure of our imaginati…

> Did they really expect that the behaviour of the very small would be exactly like that of everyday macroscopic objects? I expect a theory predicting otherwise to bear the burden of demarcating exactly where the boundary between "macroscopic" and "weird not-macroscopic" lies (waving your hands and mumbling "thermodynamics" does not count). I expect that such a theory's proponents should be absolutely burning with in…

There's a discontinuous boundary? That's news to me. It's pretty well known that classical mechanics is reproduced by quantum mechanics in the large scale. There's no discontinuity between the two. There's also a whole heap of people competing on trying to put ever and ever larger objects in superposition. Finally, decoherence has seen plenty of study and seems to be exactly what you're lamenting the lack of.

Re: Is the Schrödinger Equation True?

#107

Post by lmm »

KirillPanov wrote: post #101
lmm wrote: post #65

The Schroedinger Equation is the most true thing I've ever encountered. It is clear, simple, obvious in its correctness; the greatest piece of physics since Maxwell. Once you've understood it it becomes almost impossible to imagine that the universe could possibly work any other way. (Contrary to this article's claim, the equation describes the behaviour of Helium atoms perfectly well; it's a failure of our imaginati…

> Did they really expect that the behaviour of the very small would be exactly like that of everyday macroscopic objects? I expect a theory predicting otherwise to bear the burden of demarcating exactly where the boundary between "macroscopic" and "weird not-macroscopic" lies (waving your hands and mumbling "thermodynamics" does not count). I expect that such a theory's proponents should be absolutely burning with in…

All of the "weird" phenomena are just everyday wave phenomena as far as I can see - e.g. the uncertainty principle applies just as much to plain old classical wave packets as it does to QM objects. And as far as I know there's no "peculiar discontinuity", just a gradual irrelevance - e.g. the uncertainty principle is exactly the same when applied to objects of any size, it's just that for large objects that uncertainty is too small to be relevant.

Re: Is the Schrödinger Equation True?

#108

Post by qart »

8bitsrule wrote: post #99

It's a lovely mysterious incantation, like the (worked-over by Heaviside) Maxwell equations. But (used much like Latin), they don't speak to any human beings except those that have the leisure and capacity to learn all that math ... and then to acquire a voluminous mental store of evidence to apply it to. Real truth is plain. Newton's equations are approachable, closer to human experience and comprehension. Feynman's…

> Science is not math; it has no proofs.

A couple of the earliest things I recall proving in physics classes: 1. acceleration due to gravity on earth g is the same ~9.8 m/s² for all objects whose mass is negligible compared to the mass of the earth. 2. if it weren't for atmospheric drag, thrown projectiles fall at velocities much smaller than the escape velocity would trace a parabolic curve.

In what sense were these not proofs?

Re: Is the Schrödinger Equation True?

#109

Post by mmmBacon »

jiggawatts wrote: post #52
mmmBacon wrote: post #40

Earlier quoted context omitted.

A neutron is a particle but also a wave. You can’t have one without the other. If a neutron is a wave then is it countable?

The detection of a neutron has wave-like interference properties. There is a subtle difference between that statement and "neutrons are waves" that, again, is glossed over. The wave-like properties of all fermions can be explained with any variant of the many-worlds interpretation (MWI) that you prefer. Essentially in MWI each neutron in each universe is a point (actually three because of the quarks), but that point…

Yeah not sure I subscribe to MWI. It seems untestable and unprovable and not like science to me.

I don’t think your classical CPU analogy is really applicable here.

The wave function is exactly that, many values describing the probability of the particle in space. The act of measurement is what sets the value of the wave function. Take the classic electron diffraction experiment. It’s not the measurement that defines the wave-like property there.

Take tunneling through a potential barrier, why can the particle tunnel? Tunneling is a consequence of the wave function defining the probability of particle in all space.

Re: Is the Schrödinger Equation True?

#110

Post by ukj »

eyelidlessness wrote: post #44
ukj wrote: post #32

Earlier quoted context omitted.

Note how you are ascribing Mathematical meaning to a snail shell. You are somehow insisting that the mathematical expression (1 + sqrt(5))/2 is in some ways similar to a snail shell. Don’t you find it even a little strange that just about anyone not schooled in algebra/arithmetic would doubt your claim?

I’m confused. I’m not saying there’s “meaning” to it of any kind, only that the ratio is present and observable. I’m not “insisting” anything. Maybe you’re accustomed to every thought being a conflict, but if I wasn’t clear already I was expressing wonder around a fairly common phenomenon whose commonality isn’t well known or understood.

It's not at all a conflict.

I am simply pointing out that where both of us observe/experience the pattern, your mind ascribes to it significance by relating it to the Mathematical construct called "Golden ratio".

My mind doesn't make that relation. I call that pattern (and other patterns like it) a "snail shell pattern".

We index the experience differently.

From your perspective a Mathematical expression describes the pattern. From my perspective an English expression does.

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