3134: Wavefunction Collapse

Wavefunction Collapse

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Title text: Wavefunction collapse is only one interpretation. Under some interpretations, graduate students also have souls.

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Explanation

This is one of 52 incomplete explanations: This page was created BY A SOUlFUl PARTICLE DETECTOR. Don't remove this notice too soon. If you can fix this issue, edit the page!

There are multiple interpretations of quantum mechanics, i.e., stories to help us gain intuition. Some of these involve wave function collapse, where multiple mathematically possible states resolve into a particular state.

Quantum mechanics is commonly explained by saying that observation can cause change in the system, as in the Schrödinger's cat and Elitzur–Vaidman bomb tester thought experiments. A physical example is the Double-slit experiment, where if the apparatus interacts with the photons, such that it indicates which slit photons go through, you get a different pattern of light, compared to an experiment where this is not detected.

The use of the word "observation" causes a bit of confusion about the nature of these experiments, as some people assume that human observation is what causes this, and conclude that humans must be “special” (more so than we already are to study science in the first place) if our observation is what causes quantum effects to resolve. In actuality “observation” refers to detectors. Any interaction which indicates the presence of a "particle" affects the system, and any quantum effects or mechanics will have already resolved before a human comes along to record the results. While the idea that Consciousness causes collapse was considered seriously by earlier physicists such as Wigner, it is now very unpopular.

This comic presents three possible responses to the question: "does my consciousness affect the universe?" The 'Bad' option shows Cueball telling his student that everybody has a soul, and their individual consciousness affects reality in some way. The 'good' option shows Cueball telling his student that consciousness doesn't play a role at all, and that it is 'just a physical measurement'. The 'chaotic' option shows Cueball apparently observing that the wave function collapses only when he looks at it, because he is special in some way (in this case, Cueball is a professor while Hairy is the undergraduate student).

The title text continues the chaotic option. Graduate students are intermediate between undergraduate and professors. It is unclear whether graduate students can cause waveform collapse, and therefore have souls.

In both 660: Sympathy and 803: Airfoil there are situations where three possible replies are given. And, just like here, the first two are simply wrong and right (although in the other order). The last, in those, is Very Wrong: as opposed to the Chaotic here, but it seems like this comics interpretation called chaotic could also have been labeled very wrong, and some other similar setups escalate to a Cursed third scenario. So this is one of the generally recurring joke-payoffs, here on xkcd.

Transcript

This is one of 27 incomplete transcripts: Don't remove this notice too soon. If you can fix this issue, edit the page!

[A panel with Hairy sitting behind a desk with a hand on the table, looking at Cueball, and Cueball is standing next to him.]

Hairy: If the wavefunction only collapses when I observe it, does that mean my consciousness affects the universe?

[A panel with the caption "Bad:" on the top left, zoomed into Cueball's head]

Cueball: Yes, quantum entanglement proves that we all have souls.

[The same scene with the caption "Good:"]

Cueball: No, consciousness plays no role here. Its just physical measurement.

[The same scene with the caption "Chaotic:"]

Cueball: No, the wave function collapses when I look at it because I'm a full professor.

Cueball: It won't collapse for an undergraduate.

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Discussion

For crying out loud, the wavefunction collapse has never been observed. 38.70.240.202 02:23, 28 August 2025 (UTC)

The term professor actually can also mean "a person who affirms a faith in or allegiance to something." which continues the religious aspect of having a soul. 147.161.213.89 02:30, 28 August 2025 (UTC)

Actually, I am a god explaining their reality to my comrades, so only when we observe it does the wavefunction collapse. It will not collapse for mere characters in a false reality we created. --DollarStoreBa'al^converse 02:34, 28 August 2025 (UTC)

So many people misunderstand the Copenhagen interpretation. It is only the most basic theory that could be made based on all our experiments, which is why it says the wavefunction collapse when we measure it in an experiment. It doesnt mean it hasnt collapsed earlier, only that we know it has collapsed when we measure it.2A02:3103:4C:2400:84BF:B101:8E7D:F4C6 06:24, 28 August 2025 (UTC)

is it just me, or is this one similar to 660: Sympathy & 803: Airfoil? —Winter1760 (talk) 06:59, 28 August 2025 (UTC).

Yes there is the similarity with three option where the first two are identical but the very wrong has been canged to Chaotic in this comic. We could a mention of it at the bottom. I'll try to put it in. --Kynde (talk) 07:40, 28 August 2025 (UTC)

I think "Good", "Bad" and "Chaotic" are references to role playing games, probably Advanced Dungeons and Dragons, but perhaps others as well. Characters in such games have an "alignment", which indicates whether a character tends to do good, or tends to be destructive/evil, or can flip (chaotic). The word "alignment" also has meaning in the world of quantum physics. So this may be a deliberate conflation of worlds. I also like the double meaning of "professor" above in this context. Gjanssens (talk) 08:17, 28 August 2025 (UTC)

Randall has previously used the famous "Good/Neutral/Evil" vs "Lawful/Neutral/Chaotic" array, and subsets of it, so it's something we already know he has already used. And "Good/Bad/Chaotic" is a strange path (<any>-Good, <any>-Evil then Chaotic-<any>), and distortion of the gaming 'spectrum', if it was an intended reference. In various ways, I think it just shares the tripartite of the (Good)/(Bad)/Cursed type of sequence that some the Category:Unsolved Problems display. It's basically just a comedic triad, the shortest possible 'off the deep end' list, and I don't think the exact words matter (except being normal->normal->weird). 82.132.244.136 14:59, 28 August 2025 (UTC)

Randall pokes fun at a severe philosophic problem of all subjectivist interpretations of QM: If a "soul" is needed for wave collapse, or maybe only a being with consciousness - where shall we draw the line? Can Schrödingers cat herself collapse the wavefunction? A cockroach? A bacterium? (Mind you, they rely on a working QM as we.) Or, in the other direction as in this comic, maybe an undergrad doesn't suffice. (Add to explanation?) 2A02:2455:1960:4000:4DF1:8E5D:B4E1:C184 08:58, 28 August 2025 (UTC)

That is a NON-problem, because it isnt believed by anyone the measurement is what collapses the function, it is the conditions that are necessary to measure properties that collapses it. Which is also why the schrödingers cat is more of a joke than a real physics thought experiment. The wave functions would already have collapse d before you open the box. The only reason the copenhagen interpretation is so vague is specifically to avoid determining when wave functions collapse, so it just says they have collapsed when we make a measurement.2A02:3103:4C:2400:84BF:B101:8E7D:F4C6 12:57, 28 August 2025 (UTC)

学部生でよかった (Translation: I’m glad I’m undergraduate) 《プロキシ》(XKCD中毒者) 12:56, 28 August 2025 (UTC)

Does this mean that a red-headed professor taking a measurement won't collapse the function? 204.113.92.35 15:18, 28 August 2025 (UTC)

Seems like there's a secondary joke here implying (accurately, unfortunately) that the significance of a study is often dependent on the academic status of the person conducting it. And thus, yes, a full professor's observation of the same phenomenon "counts" more, regardless of the means of measurement. 24.53.184.90 17:31, 28 August 2025 (UTC)

we should make a category for the good-bad-weird format. seems like it's seen enough use. 152.86.78.100 00:08, 29 August 2025 (UTC)

I would not consider the Category:Unsolved Problems as being similar to this setup or the other two mentioned. And those other two do not use the same last word as this one, I think those three are a bit few. If you can find a few more along similar lines I would consider it as a category. But if so, what should we call it? --Kynde (talk) 19:37, 29 August 2025 (UTC)

As a 'super-category', yes, I would consider that all these things come under the same large umbrella. As mentioned by another, it's basically a "rule of three" punchline. It's all a lot closer together than "there are good electricians, bad electricians and dead electricians" are from "I came, I saw, I conquered". They aren't the exact same 'rule of three' format, and perhaps some sub-categorisation can group together "good/bad", "bad/good" and "other", in one case and completely different rhetoric triplets in other cases.

I also disagree about it being a 'likely' D&D reference, because it isn't (for example) any of the single rows/columns in that grid, nor "Lawful Good"/"True Neutral"/"Chaotic Evil" or "Chaotic Evil"/"True Neutral"/"Lawful God" (both the 'diagonals'), nor even something like "Neutral Good", "Chaotic Neutral", "Lawful Evil", Even assuming Bad==Evil, 'Chaotic' isn't a third item in that list, and we know that Randall could have easily written a far more 'accurate' D&D allusion than this. And Chaoticity itself isn't an obvious reference to D&D, merely something that is part of D&D, much as many other things are, what with the Chaos being a concept used long before/after the mid-'70s creation of D&D, or perhaps whenever after then that this particular alignment system got added. But that's just my own understanding. Maybe 5thEd D&D says things different from the 1st/2nd edition material that was always 'my' experience, in which case I'd appreciate a link onward to whatever states this more modern take. 92.17.62.87 01:11, 30 August 2025 (UTC)

In all editions except for the number who shall not be named (before 5th but after 3.5) D&D uses the two axis alignment system where good/evil and chaotic/lawful are unrelated to each other. 4th edition had a one dimensional LG->G->N->E->CE alignment that *maaay* fit with this Good->Bad->Chaotic[_Bad], but I doubt it since the smushing of the alignments was one of the most disliked parts of that ruleset and a lot of people who were already familiar with the two axis system just used it in 4th anyway.57.140.28.26 15:04, 2 September 2025 (UTC)

not-necessarily-exhaustive list of comics that use a similar format: 660 (right/wrong/very wrong), 803 (right/wrong/very wrong), 2529 (weirdly abstract/weirdly concrete/cursed), 3115 (vague/precise/cursed), and of course this one (bad/good/chaotic). i think that's enough for a category; is "comedic triad" a good name? 64.189.140.33 06:45, 18 September 2025 (UTC)
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