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The Zen anti-interpretation of quantum mechanics (2021)

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Re: The Zen anti-interpretation of quantum mechanics (2021)

#121

Post by sudosysgen »

kovezd wrote: post #111
scottmsul wrote: post #43

Something that's always bothered me about many-worlds is that it states the number of worlds should always be increasing exponentially. Which means from an anthropic point of view, the most likely time to be born is the last ever human, with insanely exponential odds. But many people have been born in my lifetime, ergo many-worlds seems unlikely.

I've been curious to learn theories where only a subset of scenarios beget alternative world, and many of these ultimately merge into more probable branches of reality. Keeping the total number of worlds growing at less than O(n*2) with respect to time.

In the MWI there is an infinite number of worlds (as many as there are real numbers). So the total number of worlds grows at O(1) :)

Re: The Zen anti-interpretation of quantum mechanics (2021)

#122

Post by 8bitsrule »

I'm certain that I fall and part of me lands on a rock, I'll be sorry. If someone buries gold in the ground, it's still there when someone finds the map and digs it up. Gold and granite are damned stable. If I don't know what they "really" are made of, that's an uncertainty I can live with.

When someone finds another 'world' where those properties are different, I'll be all eyes. Until then, I'll continue to suspect that some people take the current state of our mathematics too seriously. Re-normalizing? Really?

Re: The Zen anti-interpretation of quantum mechanics (2021)

#123

Post by elcritch »

dools wrote: post #102
consilient wrote: post #95

Earlier quoted context omitted.

Sure, but at that level of generality you're also talking about the mechanism by which light propagates.

Really? How does light travel in a vacuum then?

> But Maxwell’s most celebrated insight was when he combined the work of Ørsted and Faraday to explain the essence of light.

> He realised that a changing electric field could create a changing magnetic field, which would then create another electric field and so on. The result would be a self-sustaining electromagnetic field, endlessly repeating, travelling incredibly fast.

https://cosmosmagazine.com/science/physics/what-is-light/

It’s generally studied in undergraduate E&M courses.

Now if you’re curious about how E or M fields propagate you’ll start getting into quantum again. Generally this leads up to quantum electrodynamics, where as I understand it everything is treated as fields and interactions as particles.

How those fields propagate is the same as asking how wave functions “travel”. We simply don’t have to tools to even ask the right questions, IMHO.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#124

Post by tux3 »

consilient wrote: post #94
TedDoesntTalk wrote: post #86

Earlier quoted context omitted.

> There are no little billiard balls … electrons don't actually orbit Wait, what? What do they do then? My physical science education ended in high school.

The next useful falsehood on the ladder is that electrons in an atom exist as probability densities around the nucleus. Fire a photon here, and knock an electron off with this probability; fire it there, and get that probability instead. But before they interact with something, electrons aren't anywhere in particular. https://en.wikipedia.org/wiki/Atomic_orbital The real answer is that constituent parts of bound stat…

If constituent parts of bound states like atoms don't really exist as separate things, how come electrons in metals can move around readily? Is it that they're not really bound, or is it just that they 'attach' and 'detach' easily?

When I think of chemistry, it seems like even if there's some sense in which the bound atom is one big writhing mass of fields, the whole atom doesn't interract in a uniform way with the outside, right? The electrons interract with the outside a lot, the nucleus is harder to get to?

Is it wrong to say the layer of my onion exist as separate entities, when they seem to interract largely independently from the core of the onion, like they do in metals and chemistry?

(I guess the answer is still "you're going to have to learn QFT" :) But the next falsehood down seems fun to ask about too!)

Re: The Zen anti-interpretation of quantum mechanics (2021)

#125

Post by lacasito25 »

dekhn wrote: post #24

The right frame of mind is not "shut up and calculate", it's "shut up and make testable hypotheses and then invalidate them experimentally".

But what if "make testable hypotheses and then invalidate them experimentally" is wrong to begin with?

Re: The Zen anti-interpretation of quantum mechanics (2021)

#126

Post by consilient »

tux3 wrote: post #124
consilient wrote: post #94

Earlier quoted context omitted.

The next useful falsehood on the ladder is that electrons in an atom exist as probability densities around the nucleus. Fire a photon here, and knock an electron off with this probability; fire it there, and get that probability instead. But before they interact with something, electrons aren't anywhere in particular. https://en.wikipedia.org/wiki/Atomic_orbital The real answer is that constituent parts of bound stat…

If constituent parts of bound states like atoms don't really exist as separate things, how come electrons in metals can move around readily? Is it that they're not really bound, or is it just that they 'attach' and 'detach' easily? When I think of chemistry, it seems like even if there's some sense in which the bound atom is one big writhing mass of fields, the whole atom doesn't interract in a uniform way with the o…

> If constituent parts of bound states like atoms don't really exist as separate things, how come electrons in metals can move around readily? Is it that they're not really bound, or is it just that they 'attach' and 'detach' easily?

Some of both. Valence electrons in a conductor are delocalized over the entire surface.

> When I think of chemistry, it seems like even if there's some sense in which the bound atom is one big writhing mass of fields, the whole atom doesn't interract in a uniform way with the outside, right? The electrons interract with the outside a lot, the nucleus is harder to get to?

Right, at least for stable atoms at low energy scales.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#128

Post by ThePhysicist »

You could develop interpretations of classical mechanics (CM) in a similar way, but nobody does it as CM doesn't seem counter-intuitive to us. Quantum mechanics, on the other hand, is very much not intuitive, and the different interpretations are just a coping mechanism to deal with that (IMHO). Some of these interpretations actively harmed quantum mechanics research for decades, i.e. the original interpretation of what we'd call strong quantum measurements today.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#129

Post by Jensson »

lmm wrote: post #87
Jensson wrote: post #49

Earlier quoted context omitted.

So when does decoherence happen? Provide a formula for it. That is what people struggle with in quantum mechanics, MWI just deflects the question. Without a formula for when this phenomena happens any "interpretation" is just nonsense, except as a tool to get towards that formula.

Decoherence of a system happens when the entropy of entanglement is maximal, so if you want a formula then it's S(Tr_a(p_ab)) -> N/e. In practice a complex system is probably never fully decoherent, but the separability is small enough to not matter; if we're being truly rigorous we work with it as a limit, similar to how we use the "classical limit" in other parts of QM or other contexts. (Analogy: imagine saying "R…

Relativity is a real formula, you just say that decoherence seems to correlate with entropy and then gave a formula for entropy. We don't have a formula for decoherence. Any explanation for decoherence that doesn't help us find a formula for it is nonsense.

Here is a better theory than MWI: We live in a simulation, the computer is optimized so when there are too complex interactions in an area it simplifies the state into some probable untangled version. This theory predicts that decoherence thus happens at certain computational complexity levels, that is something we could try to find and test experimentally making this theory more scientific than MWI. MWI doesn't lead anywhere, it isn't science, it is just nonsense. I'm not saying my theory here is a good one, but it is better than MWI which isn't a high bar.

Re: The Zen anti-interpretation of quantum mechanics (2021)

#130

Post by atomflunder »

howling wrote: post #33

In some sense, classical probability is just the study of category of Markov Kernels [0]. We can gain much of the insight without a lot of measure theory/functional analysis machineries by restricting to its full subcategory of finite states, which gets us to the category of stochastic matrix. In this view, quantum probability (of finite states) is just about study of category of classical quantum maps described in P…

I worked through large parts of PQP ([1]) with only the prerequisites that you state, as part of a Uni course taught by Aleks Kissinger. I got quite comfortable with the formalism and could solve most problems without too much issue, but at the end I still knew nothing at all about quantum physics. YMMV
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