That always makes me wonder: in the pilot-wave picture, are there branching conscious agents within the pilot wave, in addition to the singular consciousness singled out by the “particles“?
So the question for “quantum-state realists” is whether the Schrödinger eq alone (i.e. MWI) is sufficient to explain everything (including Born’s rule) or if we need to add something extra. Or if there is sufficient horror at MWI to justify adding something extra.
Look, I’m not a pacifist. I genuinely believe that some wars are just and necessary (although they are always still horrific and no amount of justification lessens that horror or the moral weight that attaches to it). But this doesn’t meet any of the just war criteria. For anyone who wants a quick…
Updated the section of Catland on how quantum measurements become classical reality, now with more videos and a real demonstration! 🧪⚛️
(And migrated to a server that actually has a working SSL certificate!)
jesseberezovsky.com/catland/ampl...
NYT spelling bee showing “ontic” not in word list.
And now this!
It also happens at other integer ratios of frequencies, but less so as the numbers in the ratio get bigger. It’s weird because usually the spectrum of non-pure tones is invoked to explain the roughness between tones near, say, an octave. But it seems the roughness is there for pure tones as well.
Unlike the case of near-unison beating, I don’t think the power in the wave is changing in time. But then again, the perception of sound is in no way an accurate measure of power. Anyone know how to properly analyze this?
@johnmcbride4lyf.bsky.social @andytonality.bsky.social ?
Plot of ampltude vs time for a 300 Hz sine wave added to a 605 Hz sine wave, showing a wavy beating-like pattern.
The audio in the video above plays one tone at 300 Hz, and a second tone that changes every 4s from 600 to 605, 610, then 615 Hz. You can hear it too right? It seems plausible when you look at the waveform, here plotted for 300 vs. 605 Hz.
OK, so we know that two pure tones (sine waves) almost in unison produce a beating effect as the waves interfere. But what about two pure tones separated by almost an octave? I have never heard anyone say there will be beating, nor can I find any info online about it, but I swear it happens! 🧪⚛️
It's funny because I have the exact opposite sense of "How can we rescue ourselves from Everett?"
Congrats to Ben Lehmann, PhD, Pappalardo Postdoctoral Fellow at MIT, on winning the 2025 Michelson Postdoctoral Prize! 🎉
He’ll be at CWRU the week of April 13, 2026, giving two technical lectures + a colloquium. His work aims to uncover the nature of dark matter.
#CWRU #MPPL
Thanks - your book on music was an inspiration for some of the music-related things I have worked on. There's another paper on rhythm and meter currently on a second round of review at Phys Rev E - hopefully out soon.
If there is a component of the observers' wave functions correlated with each branch, why wouldn't all the branches become classical realities? I always look for an answer to this in Zurek's work, and I have not yet grasped it.
He says it, but I don't see why it should be so. He often talks about observers or agents seemingly as independent from the wave function. But at the same time, it doesn't seem to be his intent to postulate something outside of the wave function.
Many of the ideas in the book are also in this paper: www.mdpi.com/1099-4300/24.... Zurek argues that while his results may be consistent with MW, he prefers his "existential interpretation," which I do not understand. It has something to with elevating information to be more real.
About this, he says “...such a ‘Many Worlds’ view where all the branches are equally real now seems like a very classical interpretation in that it reduces information to the subservient role it played in the Newtonian setting.” (p 321) I don’t see the problem with that.
This seems like a key issue with the existential interpretation, and I don’t understand why Zurek doesn’t spend more time explaining this. Maybe I am just not grasping something, but it still seems reasonable to me to just take a straightforward ontic view of the wave function Zurek is describing.
But MW would say that in another branch, there is another “version” of the observers seeing a different pointer state. It is never clear to me why Zurek singles out one branch and ignores the others. He says, “Such branches can be ‘pruned.’” (p. 322). I don’t know what that means.
The environment in each branch contains many redundant copies of information about a particular pointer state. So indeed, the component of observers’ wave functions *in a branch* would gather information from a fragment of the environment and all reach consensus about which pointer state it is.
But the “existential interpretation” remains unclear to me, even after reading the explanation in the new book. The mathematics (decoherence, einselection, quantum Darwinism) describe a wave function that branches.
“…One can still suppose that there is an ontic universal state vector, its evolution in the all-encompassing Hilbert space as deterministic as the trajectory of a point in the classical phase space.” (p. 321)
In both his papers and the recent book, Zurek makes it pretty clear that his mathematical results are, in fact, consistent with MW. In the book, he says “Mathematics alone does not prevent one from demoting the role of information suggested by these considerations: …”
In fact, it was Zurek’s papers (of which I am a huge fan) that originally made me lean towards the Everettian picture. Decoherence, einselection, envariance, and quantum Darwinism all seemed to so nicely point to how MW would work in practice.
It’s the same in some of Zurek’s papers: the meat of the paper reads as if it is explaining MW, but then at the end he says “Yes, this is all consistent with MW but we don’t have to accept it.” Some words then follow describing his “existential interpretation.”
OK, indeed this is hard to discuss in 300 character chunks, but I’ll have a go at it.
The thing is, the first 300 pages or so of the book can be read as a brilliant advancement of the Everettian picture.
And his political views are… above reproach.
New York Times Spelling Bee, with the word Embiggen spelled out.
It’s a perfectly cromulent word.
I believe Zurek’s argument is essentially the same as that used in Many Worlds. That is, arguing that certain entangled parts of the wave function with equal amplitude must be assigned equal probability, and then unequal parts can be unitarily divided up into equal parts so as to yield Born’s rule.
Is the book something different than his previously published work?
Not at all clear to me how quantum Darwinism could single out one of these as “real” just from standard QM. (It selects which basis becomes classical, but not which outcome in that basis)
