{
 "slug": "schrodingers-cat",
 "claims": [
  {
   "id": "essay-title-journal",
   "kind": "citation",
   "claim": "a long three-part essay, “Die gegenwärtige Situation in der Quantenmechanik” (The present situation in quantum mechanics), printed in Die Naturwissenschaften in November and December 1935",
   "source": "https://api.crossref.org/works/10.1007/BF01491891",
   "excerpt": "10.1007/BF01491891  title \"Die gegenwärtige Situation in der Quantenmechanik\"; author E. Schrödinger; container \"Die Naturwissenschaften\"; volume 23; issue 48; page 807-812; published-print 1935-11",
   "where": "Crossref records for all three parts: 1935-11, 1935-12, 1935-12",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schrodinger-1935-german.txt",
   "doi": "10.1007/BF01491891"
  },
  {
   "id": "epr-title",
   "kind": "citation",
   "claim": "Earlier that year Einstein, Podolsky and Rosen had published “Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?”",
   "source": "https://api.crossref.org/works/10.1103/PhysRev.47.777",
   "excerpt": "\"Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?\"",
   "where": "Crossref: issued 1935-05-15",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/epr-1935.txt",
   "doi": "10.1103/PhysRev.47.777"
  },
  {
   "id": "footnote-motivated",
   "kind": "fact",
   "claim": "Schrödinger says in a footnote that it prompted his essay",
   "source": "https://www.unicamp.br/~chibeni/textosdidaticos/schrodinger-1935-cat.pdf",
   "excerpt": "which, Schrödinger says, in a footnote, motivated his offering",
   "where": "Trimmer, introduction, p. 323",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/trimmer-1980.txt"
  },
  {
   "id": "cat-paragraph",
   "kind": "quote",
   "claim": "In John D. Trimmer's 1980 English translation the paragraph reads",
   "quote": "One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following diabolical device (which must be secured against direct interference by the cat): in a Geiger counter there is a tiny bit of radioactive substance, so small, that perhaps in the course of one hour one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges and through a relay releases a hammer which shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The first atomic decay would have poisoned it. The ψ-function of the entire system would express this by having in it the living and the dead cat (pardon the expression) mixed or smeared out in equal parts.",
   "source": "https://www.unicamp.br/~chibeni/textosdidaticos/schrodinger-1935-cat.pdf",
   "excerpt": "One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following diabolical device (which must be secured against direct interference by the cat): in a Geiger counter there is a tiny bit of radioactive substance, *so* small, that *perhaps* in the course of one hour one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges and through a relay releases a hammer which shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives *if* meanwhile no atom has decayed. The first atomic decay would have poisoned it. The ψ-function of the entire system would express this by having in it the living and the dead cat (pardon the expression) mixed or smeared out in equal parts.",
   "where": "section 5, p. 328 (asterisks mark the translation's italics)",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/trimmer-1980.txt"
  },
  {
   "id": "next-paragraph",
   "kind": "quote",
   "claim": "The next paragraph says what the case is for",
   "quote": "It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be resolved by direct observation. That prevents us from so naively accepting as valid a ... blurred model ... for representing reality. In itself it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks.",
   "source": "https://www.unicamp.br/~chibeni/textosdidaticos/schrodinger-1935-cat.pdf",
   "excerpt": "It is typical of these cases that an indeterminacy originally restricted to the atomic domain becomes transformed into macroscopic indeterminacy, which can then be *resolved* by direct observation. That prevents us from so naively accepting as valid a \"blurred model\" for representing reality. In itself it would not embody anything unclear or contradictory. There is a difference between a shaky or out-of-focus photograph and a snapshot of clouds and fog banks.",
   "where": "section 5, p. 328",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/trimmer-1980.txt"
  },
  {
   "id": "section-title",
   "kind": "fact",
   "claim": "The section asks whether the quantities of quantum mechanics are really blurred",
   "source": "https://www.unicamp.br/~chibeni/textosdidaticos/schrodinger-1935-cat.pdf",
   "excerpt": "5. Are the Variables Really Blurred?",
   "where": "p. 327",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/trimmer-1980.txt"
  },
  {
   "id": "nucleus",
   "kind": "quote",
   "claim": "Inside the nucleus, he says, “blurring doesn't bother us”.",
   "quote": "blurring doesn't bother us",
   "source": "https://www.unicamp.br/~chibeni/textosdidaticos/schrodinger-1935-cat.pdf",
   "excerpt": "Inside the nucleus, blurring doesn't bother us.",
   "where": "section 5, p. 327",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/trimmer-1980.txt"
  },
  {
   "id": "sect6",
   "kind": "quote",
   "claim": "The section after it puts it in one line",
   "quote": "In Sect. 5. we saw that the indeterminacy is not even an actual blurring, for there are always cases where an easily executed observation provides the missing knowledge.",
   "source": "https://www.unicamp.br/~chibeni/textosdidaticos/schrodinger-1935-cat.pdf",
   "excerpt": "In Sect. 5. we saw that the indeterminacy is not even an actual blurring, for there are always cases where an easily executed observation provides the missing knowledge.",
   "where": "section 6, p. 328",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/trimmer-1980.txt"
  },
  {
   "id": "burleske",
   "kind": "quote",
   "claim": "the German, as German Wikipedia quotes it, says “ganz burleske Fälle”",
   "quote": "ganz burleske Fälle",
   "source": "https://de.wikipedia.org/w/index.php?title=Schr%C3%B6dingers_Katze&action=raw",
   "excerpt": "Man kann auch ganz burleske Fälle konstruieren.",
   "where": "a secondary transcription; the original was not read",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schrodinger-1935-german.txt"
  },
  {
   "id": "gunpowder",
   "kind": "quote",
   "claim": "On 8 August 1935 Einstein had written to Schrödinger about a charge of gunpowder that could go off by itself, with an average life of a year",
   "quote": "a sort of blend of not-yet and already-exploded systems ... Through no art of interpretation can this psi-function be turned into an adequate description of a real state of affairs; in reality there is no intermediary between exploded and not-exploded.",
   "source": "https://plato.stanford.edu/entries/qt-epr/",
   "excerpt": "perhaps\na charge of gunpowder that, by means of intrinsic forces, can\nspontaneously combust, and where the average life span of the whole\nsetup is a year. In principle this can quite easily be represented\nquantum-mechanically. In the beginning the psi-function characterizes\na reasonably well-defined macroscopic state. But, according to your\nequation [i.e., the Schrödinger equation], after the course of a\nyear this is no longer the case. Rather, the psi-function then\ndescribes a sort of blend of not-yet and already-exploded systems.\nThrough no art of interpretation can this psi-function be turned into\nan adequate description of a real state of affairs; in reality there\nis no intermediary between exploded and not-exploded.",
   "where": "Fine, SEP, quoting Fine 1996 p. 78; the letter of August 8, 1935",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "answered-with-cat",
   "kind": "fact",
   "claim": "Schrödinger answered with the cat.",
   "source": "https://plato.stanford.edu/entries/qt-epr/",
   "excerpt": "Schrödinger first produced the cat example in his reply of\nSeptember 19, 1935 to Einstein’s August 8 gunpowder letter.",
   "where": "the date is disputed (see the page's note); the fact of the reply is not",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "your-cat",
   "kind": "quote",
   "claim": "Einstein replied: “Your cat shows that we are in complete agreement.”",
   "quote": "Your cat shows that we are in complete agreement",
   "source": "https://nautil.us/how-einstein-and-schrdinger-conspired-to-kill-a-cat-236140",
   "excerpt": "“Your cat shows that we are in complete agreement,” he wrote in early September. “A ψ-function that contains the living as well as the dead cat just cannot be taken as a description of the real state of affairs.”",
   "where": "Kaiser 2016, citing Fine, The Shaky Game, letter of 4 September 1935",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "psi-cannot",
   "kind": "quote",
   "claim": "in Einstein's words in that reply, that “A ψ-function that contains the living as well as the dead cat just cannot be taken as a description of the real state of affairs.”",
   "quote": "A ψ-function that contains the living as well as the dead cat just cannot be taken as a description of the real state of affairs.",
   "source": "https://nautil.us/how-einstein-and-schrdinger-conspired-to-kill-a-cat-236140",
   "excerpt": "“A ψ-function that contains the living as well as the dead cat just cannot be taken as a description of the real state of affairs.”",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "1950-gunpowder",
   "kind": "quote",
   "claim": "Fifteen years later, writing to Schrödinger again, Einstein described the box as holding a “charge of gun powder” and the cat",
   "quote": "charge of gun powder",
   "source": "https://erenow.org/common/letters-on-wave-mechanics/19.php",
   "excerpt": "refuted, most elegantly by your system of radioactive atom + Geiger counter + amplifier + charge of gun powder + cat in a box",
   "where": "letter of 22 December 1950; an unofficial transcription of Przibram (ed.), Letters on Wave Mechanics; English Wikipedia's quotation also has \"charge of gun powder\"",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "many-copies",
   "kind": "fact",
   "claim": "Every real experiment of this kind has to be repeated on many freshly prepared copies",
   "source": "https://www.nobelprize.org/uploads/2018/06/haroche-lecture.pdf",
   "excerpt": "Acquiring knowledge about a quantum state always requires such a\n             statistical procedure and these experiments rely on the fact that we can prepare\n             an arbitrary number of copies of the state to be reconstructed",
   "where": "Haroche, Nobel lecture 2012, p. 90",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/brune-1996.txt"
  },
  {
   "id": "song-formula",
   "kind": "fact",
   "claim": "Chao Song and colleagues, who made such states with superconducting circuits in 2019, write the average as ⟨P(γ)⟩ = 2 |ρ00...0, 11...1| cos(Nγ + ϕ)",
   "source": "https://arxiv.org/pdf/1905.00320",
   "excerpt": "which is given by hP(γ)i =\n2 |ρ00...0, 11...1 | cos(N γ + ϕ) for the abovementioned GHZ\nwavefunction",
   "where": "arXiv full text; \"hP(γ)i\" is the extraction of ⟨P(γ)⟩; the qubits are superconducting",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/song-2019.txt",
   "doi": "10.1126/science.aay0600"
  },
  {
   "id": "omran-linear",
   "kind": "quote",
   "claim": "which is what Omran and colleagues saw with 20 atoms in 2019",
   "quote": "the frequency of the measured parity oscillations grows linearly with N",
   "source": "https://arxiv.org/pdf/1905.05721",
   "excerpt": "the frequency of the measured parity oscillations grows linearly with N",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/omran-2019.txt",
   "doi": "10.1126/science.aax9743"
  },
  {
   "id": "zeh-1970",
   "kind": "fact",
   "claim": "Its key idea was first put down by H. Dieter Zeh in 1970",
   "source": "https://arxiv.org/pdf/1911.06282",
   "excerpt": "This role of the environment was\nalready spelled out by Zeh [1] in his 1970 paper marking the birth of decoherence theory",
   "where": "Schlosshauer 2019, sec. 2; \"In memory of H. Dieter Zeh (1932–2018)\"; also sec. 1: \"first spelled out almost fifty years ago by Zeh\"",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt",
   "doi": "10.1016/j.physrep.2019.10.001"
  },
  {
   "id": "1980s",
   "kind": "fact",
   "claim": "it was developed in the 1980s, chiefly by Zurek, with the first estimates of how fast it happens worked out by Joos and Zeh and by Zurek",
   "source": "https://arxiv.org/pdf/1911.06282",
   "excerpt": "In the 1980s, the formalism of decoherence was further developed, chiefly by Zurek [2, 3], and the first concrete decoherence models and\nnumerical estimates of decoherence rates were worked out by Joos and Zeh [21] and Zurek [22]",
   "where": "sec. 1",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt"
  },
  {
   "id": "unitary",
   "kind": "fact",
   "claim": "Nothing in it is added to quantum mechanics: the strays obey the same equations as the cat.",
   "source": "https://arxiv.org/pdf/1911.06282",
   "excerpt": "the dynamics of decoherence processes are based entirely on the standard, unitary",
   "where": "sec. 7.1",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt"
  },
  {
   "id": "zurek-formula",
   "kind": "fact",
   "claim": "The coherence between the two places dies in (λT/Δx)² of the time the object would take to settle back to rest, where λT = ħ/√(2MkBT) is its thermal de Broglie wavelength",
   "source": "https://arxiv.org/pdf/quant-ph/0105127",
   "excerpt": "λ_T = ħ / √(2 M k_B T)",
   "where": "RMP Eqs. 5.35 and 5.38 (tau_D^-1 = gamma ((x - x')/lambda_T)^2, gamma the relaxation rate), transcribed from the page image",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/zurek-decoherence.txt",
   "doi": "10.1103/RevModPhys.75.715"
  },
  {
   "id": "zurek-1040",
   "kind": "quote",
   "claim": "Zurek states it as “approximately 1040 times faster than relaxation”",
   "quote": "approximately 10 ... times faster than relaxation",
   "source": "https://arxiv.org/pdf/quant-ph/0105127",
   "excerpt": "For a mass 1g at room temperature and for the separation x′ − x =1cm, Eq. (5.38) predicts decoherence approximately 10^40 times faster than relaxation!",
   "where": "RMP sec. V; the page prints the exponent as a superscript",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/zurek-decoherence.txt"
  },
  {
   "id": "zurek-salt",
   "kind": "quote",
   "claim": "He adds that these estimates “should be taken with a grain of salt”",
   "quote": "should be taken with a grain of salt",
   "source": "https://arxiv.org/pdf/quant-ph/0105127",
   "excerpt": "These estimates for the rates of decoherence and relaxation should be taken with a grain of salt: Often the assumptions that have led to the simple high temperature master equation (5.29) are not valid",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/zurek-decoherence.txt"
  },
  {
   "id": "zurek-cap",
   "kind": "fact",
   "claim": "the rate cannot really be faster than the rate at which the superposition was made in the first place",
   "source": "https://arxiv.org/pdf/quant-ph/0105127",
   "excerpt": "the decoherence rate cannot be faster than inverse of the spectral cutoff in Eq. (5.27), or than the rate with which the superposition is created.",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/zurek-decoherence.txt"
  },
  {
   "id": "brune",
   "kind": "fact",
   "claim": "a microwave field of a few photons in a cavity, put by Rydberg atoms into two phases at once (Brune, Haroche and colleagues)",
   "source": "https://inspirehep.net/api/doi/10.1103/PhysRevLett.77.4887?format=json",
   "excerpt": "A mesoscopic superposition of quantum states involving radiation fields with classically distinct phases was created and its progressive decoherence observed. The experiment involved Rydberg atoms interacting one at a time with a few photon coherent field trapped in a high Q microwave cavity.",
   "where": "abstract (APS, via INSPIRE)",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/brune-1996.txt",
   "doi": "10.1103/PhysRevLett.77.4887"
  },
  {
   "id": "brune-quote",
   "kind": "quote",
   "claim": "The decoherence phenomenon transforming this superposition into a statistical mixture was observed while it unfolded",
   "quote": "The decoherence phenomenon transforming this superposition into a statistical mixture was observed while it unfolded",
   "source": "https://inspirehep.net/api/doi/10.1103/PhysRevLett.77.4887?format=json",
   "excerpt": "The decoherence phenomenon transforming this superposition into a statistical mixture was observed while it unfolded",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/brune-1996.txt"
  },
  {
   "id": "brune-separation",
   "kind": "fact",
   "claim": "cats whose two parts were further apart decohered faster",
   "source": "https://www.nobelprize.org/uploads/2018/06/haroche-lecture.pdf",
   "excerpt": "The shortening of the decoherence time as the separation is in-\n             creased was clearly demonstrated.",
   "where": "Haroche, Nobel lecture, on the 1996 experiment [66]",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/brune-1996.txt"
  },
  {
   "id": "arndt",
   "kind": "quote",
   "claim": "de Broglie wave interference, by diffraction at a grating; then “the most massive and complex object in which wave behaviour has been observed”",
   "quote": "the most massive and complex object in which wave behaviour has been observed",
   "source": "https://www.nature.com/articles/44348",
   "excerpt": "Here we report the observation of de Broglie wave interference of C60 molecules by diffraction at a material absorption grating. This molecule is the most massive and complex object in which wave behaviour has been observed.",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/arndt-1999.txt",
   "doi": "10.1038/44348"
  },
  {
   "id": "monz",
   "kind": "fact",
   "claim": "for up to 8 ions, coherence decayed in proportion to the square of the number of ions, as expected for noise that hits all of them alike",
   "source": "https://arxiv.org/abs/1009.6126",
   "excerpt": "We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits. By investigating the coherence of up to 8 ions over time, we observe a decay proportional to the square of the number of qubits. The observed decay agrees with a theoretical model which assumes a system affected by correlated, Gaussian phase noise.",
   "where": "abstract",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/monz-2011.txt",
   "doi": "10.1103/PhysRevLett.106.130506"
  },
  {
   "id": "monz-14",
   "kind": "fact",
   "claim": "GHZ states, this page's “both” box, of up to 14 trapped ions (Monz, Blatt and colleagues)",
   "source": "https://arxiv.org/abs/1009.6126",
   "excerpt": "We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits.",
   "where": "abstract; the paper's GHZ form is (|0...0> + |1...1>)/sqrt(2), the \"both\" box at even odds; ion-trap qubits",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/monz-2011.txt"
  },
  {
   "id": "omran-20",
   "kind": "fact",
   "claim": "GHZ states of 20 atoms (Omran, Lukin and colleagues)",
   "source": "https://inspirehep.net/api/doi/10.1126/science.aax9743?format=json",
   "excerpt": "we demonstrate the creation of “Schrödinger cat” states of the Greenberger-Horne-Zeilinger (GHZ) type with up to 20 qubits",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/omran-2019.txt"
  },
  {
   "id": "omran-fid",
   "kind": "fact",
   "claim": "fidelities of at least 0.542 for the 20 atoms",
   "source": "https://arxiv.org/pdf/1905.05721",
   "excerpt": "we extracted a lower bound for the\n20-atom GHZ state fidelity of F ≥ 0.542(18).",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/omran-2019.txt"
  },
  {
   "id": "song-fid",
   "kind": "fact",
   "claim": "0.525 ± 0.005 for the 18 qubits",
   "source": "https://arxiv.org/pdf/1905.00320",
   "excerpt": "we measure a fidelity figure of 0.525 ± 0.005\nfor 18 qubits, which confirms the genuine eighteen-partite",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/song-2019.txt"
  },
  {
   "id": "threshold",
   "kind": "fact",
   "claim": "above the 0.5 threshold that certifies all the parts are genuinely entangled together",
   "source": "https://arxiv.org/pdf/1905.05721",
   "excerpt": "Extracting the GHZ fidelity from these measurements shows that\nwe surpass the threshold of F = 0.5 for all system sizes\nstudied",
   "where": "also Song: \"all confirming genuine multipartite entanglement\"",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/omran-2019.txt"
  },
  {
   "id": "fein",
   "kind": "quote",
   "claim": "molecules beyond 25,000 atomic mass units, up to 2,000 atoms (Fein, Arndt and colleagues)",
   "quote": "by far the heaviest objects shown to exhibit matter-wave interference to date",
   "source": "https://www.nature.com/articles/s41567-019-0663-9",
   "excerpt": "Here, we report interference of a molecular library of functionalized oligoporphyrins4 with masses beyond 25,000 Da and consisting of up to 2,000 atoms, by far the heaviest objects shown to exhibit matter-wave interference to date.",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/fein-2019.txt",
   "doi": "10.1038/s41567-019-0663-9"
  },
  {
   "id": "bild",
   "kind": "fact",
   "claim": "a mechanical resonator with an effective mass of 16.2 micrograms, about 1017 atoms (Bild, Chu and colleagues)",
   "source": "https://arxiv.org/abs/2211.00449",
   "excerpt": "Here we demonstrate the preparation of a mechanical resonator with an effective mass of 16.2 micrograms in Schrödinger cat states of motion",
   "where": "arXiv abstract; the published abstract: \"the ∼10^17 constituent atoms are in a superposition of two opposite-phase oscillations\"",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/bild-2023.txt",
   "doi": "10.1126/science.adf7553"
  },
  {
   "id": "bild-quote",
   "kind": "quote",
   "claim": "“a superposition of two opposite-phase oscillations”, with its decoherence measured",
   "quote": "a superposition of two opposite-phase oscillations",
   "source": "https://api.crossref.org/works/10.1126/science.adf7553",
   "excerpt": "where the ∼10^17 constituent atoms are in a superposition of two opposite-phase oscillations. We control the size and phase of the superpositions and investigate their decoherence dynamics.",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/bild-2023.txt"
  },
  {
   "id": "schlosshauer",
   "kind": "quote",
   "claim": "Maximilian Schlosshauer, in a 2019 review, is flat about it",
   "quote": "The measurement problem as just defined cannot be solved by decoherence",
   "source": "https://arxiv.org/pdf/1911.06282",
   "excerpt": "The measurement problem as just defined cannot be solved by decoherence [6, 9].",
   "where": "sec. 7.1",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt"
  },
  {
   "id": "bacciagaluppi",
   "kind": "quote",
   "claim": "Guido Bacciagaluppi puts the gap in one sentence",
   "quote": "does explain why we do not observe superpositions of measurement results, it does not explain why we do observe measurement results in the first place.",
   "source": "https://plato.stanford.edu/entries/qm-decoherence/",
   "excerpt": "while decoherence does explain why we do\nnot observe superpositions of measurement results, it does\nnot explain why we do observe measurement results in\nthe first place.",
   "where": "SEP, sec. 2.1",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt"
  },
  {
   "id": "interpretations",
   "kind": "fact",
   "claim": "What fills that gap depends on the interpretation: Bohm's, Everett's, the collapse theories, versions of Copenhagen.",
   "source": "https://plato.stanford.edu/entries/qm-decoherence/",
   "excerpt": "whether this\nbe one that attempts to solve the measurement problem, such\nas Bohm, Everett or GRW; or one that attempts to dissolve it,\nsuch as various versions of the Copenhagen interpretation.",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt"
  },
  {
   "id": "collapse-modify",
   "kind": "fact",
   "claim": "Collapse theories modify the Schrödinger equation itself",
   "source": "https://plato.stanford.edu/entries/qm-decoherence/",
   "excerpt": "either the composite system is not described by such a superposition,\nbecause the Schrödinger equation actually breaks down and needs\nto be modified",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/schlosshauer-2019.txt"
  },
  {
   "id": "fein-bounds",
   "kind": "quote",
   "claim": "interference with ever heavier molecules, as Fein and colleagues write, places “more stringent bounds” on them",
   "quote": "more stringent bounds",
   "source": "https://www.nature.com/articles/s41567-019-0663-9",
   "excerpt": "By increasing the mass of the interfering particles and the macroscopicity of the superposition2, more stringent bounds can be placed on modified quantum theories such as objective collapse models3.",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/fein-2019.txt"
  },
  {
   "id": "date-note-sep",
   "kind": "fact",
   "claim": "The Stanford Encyclopedia of Philosophy's entry on the EPR argument says his reply was dated 19 September 1935",
   "source": "https://plato.stanford.edu/entries/qt-epr/",
   "excerpt": "his reply of\nSeptember 19, 1935 to Einstein’s August 8 gunpowder letter",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "date-note-kaiser",
   "kind": "fact",
   "claim": "David Kaiser, citing Arthur Fine's The Shaky Game, dates it 19 August and dates Einstein's “Your cat shows” answer 4 September",
   "source": "https://nautil.us/how-einstein-and-schrdinger-conspired-to-kill-a-cat-236140",
   "excerpt": "Letter from Schrödinger to Einstein, dated 19 August 1935 and from Einstein to Schrödinger, dated 4 September 1935.",
   "where": "Kaiser, endnote 9",
   "fetched": "2026-10-11",
   "kept": "research/schrodingers-cat/sources/einstein-schrodinger-letters.txt"
  },
  {
   "id": "coh",
   "kind": "data",
   "claim": "In a “both” box at one hour the coherence is 0.5",
   "source": "verify-schrodingers-cat.mjs",
   "note": "recomputed by the verifier from public/strata/schrodingers-cat/engine.mjs and its own state-vector simulation"
  },
  {
   "id": "c100",
   "kind": "data",
   "claim": "100 strays leave 0.366 of the fringe, and it halves every 69 strays",
   "source": "verify-schrodingers-cat.mjs",
   "note": "recomputed by the verifier from public/strata/schrodingers-cat/engine.mjs and its own state-vector simulation"
  },
  {
   "id": "zurek-num",
   "kind": "data",
   "claim": "the formula gives a thermal wavelength of 3.7 × 10⁻²³ metres and a ratio of 1.3 × 10⁻⁴¹",
   "source": "verify-schrodingers-cat.mjs",
   "note": "recomputed by the verifier from public/strata/schrodingers-cat/engine.mjs and its own state-vector simulation"
  },
  {
   "id": "cat-num",
   "kind": "data",
   "claim": "a 4 kg cat has a thermal wavelength of 5.8 × 10⁻²⁵ metres",
   "source": "verify-schrodingers-cat.mjs",
   "note": "recomputed by the verifier from public/strata/schrodingers-cat/engine.mjs and its own state-vector simulation"
  },
  {
   "id": "opening-sim",
   "kind": "data",
   "claim": "for one, three and five parts, every possible pattern of answers comes out with the same probability from both boxes, to twelve decimal places",
   "source": "verify-schrodingers-cat.mjs",
   "note": "recomputed by the verifier from public/strata/schrodingers-cat/engine.mjs and its own state-vector simulation"
  }
 ]
}