---
slug: the-spring-the-muscle-cant-match
passed: 2026-10-14
by: the assay line (research/assay-line/cited-1014b/), Codex fixer directed by claude-assaying-boyle-1014; source record by Codex, checked by Codex and a Claude agent
checked: 142
confirmed: 130
wrong: 11
unverifiable: 0
observed: 0
stale: 1
---

This pass applies the directing instance's triage to the layer read at 3206ca4d4a. The fixer independently reread the papers and local evidence for all 12 triage items, repaired three substantive errors and the agreed MINOR defects, and dated the metadata revision. The CONFIRMED entries retain the source rereads and computations recorded in research/assay-line/cited-1014b/the-spring-the-muscle-cant-match/N2-codex.md and N2-claude.md at their 67088387e0 pin, with checker provenance on each line; triaged entries use the directing instance's final levels. The wrong count includes five WRONG lines and six MINOR lines. The three repeated checker findings retain separate claim and finding lines while sharing their underlying repair.

## Claims

- MINOR | [X1: muscle-power-conditions] Muscle type, temperature, activation, strain path, and the meaning of peak versus cyclic power all matter. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring; https://journals.biologists.com/jeb/article/214/3/452/33507/Scaling-of-mechanical-power-output-during-burst; research/assay-line/cited-1014b/the-spring-the-muscle-cant-match/N1-sources.json | The recorded temperature quotation supported only part of the list. Longo Box 1 and Jackson and Dial, Work and power calculations and Discussion after Fig. 7, support the remaining distinctions. Added four located passages to N1-sources.json, retaining the original quotation and page wording.
- WRONG | [X2: force-velocity-load-1] In a minimal force-velocity model, a small inertial load quickly outruns its motor. | https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf; public/strata/the-spring-the-muscle-cant-match/index.html | Ilton article p. 2 of 11 gives an asymptotic motor-speed limit; Fig. 1B identifies load velocity with motor velocity. The page directTakeoffFraction returns no more than 1. Replaced outruns with approaches the unloaded speed and added a dated correction.
- WRONG | [X3: model-routes-2] The blue route is the same motor driving the body directly through the same stroke. | public/strata/the-spring-the-muscle-cant-match/index.html, modelAt and drawPowerCurves | drawPowerCurves plots spring loading in blue using q = 1 - exp(-tau); modelAt computes direct drive separately. Fresh calculation at 100 kg gives 5500 W loading and 3886.007589 W direct drive. Corrected the description and added one dated correction shared with K2.
- MINOR | [X4: crossover-other-assumptions] Change spring mass, efficiency, geometry, muscle activation, length-tension effects, gearing, or the performance target, and it moves. | https://pmc.ncbi.nlm.nih.gov/articles/PMC6907395/; https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf; research/assay-line/cited-1014b/the-spring-the-muscle-cant-match/N1-sources.json | The original Sutton quotation refers to activation and length-tension assumptions. Added the surrounding activation passage, the separate lever paragraph, and Ilton article pp. 2-3 on performance targets and nonideal springs. Original quotation and page claim retained.
- MINOR | [X5: citation-6] Sheila N. Patek and colleagues, “Beyond power amplification,” Journal of Experimental Biology 222 (2019), jeb197889. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring; research/the-spring-the-muscle-cant-match/README.md | The publisher byline lists S. J. Longo first and S. N. Patek last; research README source 7 gives Sarah J. Longo. Both are authors. Changed the named citation author to Longo for bibliographic precision. Shared MINOR repair with K3, with no page correction line.
- STALE | [X6: modified-date] "dateModified":"2026-07-23" | git show 1c4c7c5c41b -- public/strata/the-spring-the-muscle-cant-match/index.html; git show 2e60bcb5dd1 -- public/strata/the-spring-the-muscle-cant-match/index.html | The field retained the publication date after tracked changes on 2026-08-25 and 2026-10-01. Set dateModified to 2026-10-14 for this revision, retaining datePublished. The explicit metadata exception needs no separate Updated line.
- WRONG | [X7: scale-tick-labels] 100 500 2,500 12,500 100,000 W/kg | public/strata/the-spring-the-muscle-cant-match/index.html, scale-tick spans and logPosition | logPosition maps 100 to 100000 W/kg onto 0 to 100 percent. Recalculation gives 23.299000145, 46.598000289 and 69.897000434 percent for the three interior labels. Moved them to those positions rounded to three decimals, with one correction shared with K5.
- MINOR | [K1: 2003-elastic-store] Burrows' short 2003 report called the elastic store strengthened thoracic cuticle that might contain resilin, or the large tendon. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf, p. 509 | Burrows p. 509 proposes storage in the cuticle or tendon conditionally. Changed called the elastic store to suggested that the energy could be stored, preserving both alternatives and the later anatomical discussion. MINOR, recorded without a correction line.
- WRONG | [K2: model-routes-2] The blue route is the same motor driving the body directly through the same stroke. | public/strata/the-spring-the-muscle-cant-match/index.html, modelAt and drawPowerCurves | Same blue-curve error as X3. Source code and the fresh 100 kg calculation distinguish 5.50 kW spring loading from 3.89 kW direct drive. Shares the prose fix and correction line with X3.
- MINOR | [K3: citation-6] Sheila N. Patek and colleagues, “Beyond power amplification,” Journal of Experimental Biology 222 (2019), jeb197889. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring; research/the-spring-the-muscle-cant-match/README.md | Same bibliographic precision issue as X5. Longo is first author and Patek is a real coauthor listed last. Retained the triage MINOR classification and shares the Longo citation repair, without a correction line.
- MINOR | [K4: research-apparatus] Full citations, the verified-versus-modelled boundary, and reproducibility notes live in research/the-spring-the-muscle-cant-match/README.md. | research/the-spring-the-muscle-cant-match/README.md; public/strata/the-spring-the-muscle-cant-match/index.html; public/checks/research/the-spring-the-muscle-cant-match/ | The README contains the described sections, but the page renders its path as an unlinked span and no README is shipped in this layer public directory. Removed that pointer sentence. Fresh HEAD probes returned 403 for both README routes and the verifier control, so they do not reproduce the earlier 404 finding.
- WRONG | [K5: scale-tick-labels] 100 500 2,500 12,500 100,000 W/kg | public/strata/the-spring-the-muscle-cant-match/index.html, scale-tick spans and logPosition | Same axis error as X7. The original quarter-scale positions represent approximately 562, 3162 and 17783 W/kg. Shares the three tick-position changes and correction line with X7.
- CONFIRMED | [seo-title] How a Froghopper Jumps With Power No Muscle Can Produce | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): Burrows 2003 p. 509: "The forces powering the jump could not be produced by direct muscle contractions over the short distances and brief time available"; 36 and 74 W/g of jumping muscle
- CONFIRMED | [kicker] Life, under a millisecond | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "the simultaneous extension of both hind legs in less than 1 ms"; "The time taken from the first visible leg movements to the insect becoming airborne is no more than 1 ms"
- CONFIRMED | [dek-power] Measured froghopper jumps demand tens of thousands of watts per kilogram of jumping muscle, far beyond a conservative 250-500 W/kg comparison band. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "giving a power output of 36 W g-1 and a maximum for the best jumps of 74 W g-1" = 36,000 and 74,000 W/kg; the 250-500 band is the page's declared comparison, top edge near Jackson and Dial's 471 W/kg
- CONFIRMED | [dek-controls] Change the launch-budget inputs, move body mass through a declared toy motor-spring-latch model, and see which claims survive. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): sliders energy, launch-time, muscle-fraction (updateBudget) and log body-mass slider (updateModel) all exist and drive the readouts
- CONFIRMED | [milligram-body] A meadow froghopper is weighed in milligrams. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "Froghoppers, Philaenus spumarius (Linnaeus), have a mass (m) of 12.3 +/- 0.7 mg"; Wikipedia: "Philaenus spumarius, the meadow froghopper or meadow spittlebug"
- CONFIRMED | [jump-comparison] Its jump is not a small version of ours. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): interpretive; Burrows contrasts long-legged levering jumpers with short-legged catapults and gives force "414 times their body weight" against "humans (2-3 times)"
- CONFIRMED | [takeoff-measurements] Malcolm Burrows measured a mean takeoff speed of 2.8 m/s, rising to 4 m/s in the best jumps, with the hind legs extending in less than 1 ms. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "mean take-off velocity (v) is 2.8 +/- 0.1 m s-1 (or, for the best jumps, 4 m s-1)"; hind legs extend "in less than 1 ms"
- CONFIRMED | [muscle-fraction] He measured the paired jumping muscles at about 11% of body mass. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "About 11% (n = 5) of the body weight is attributable to the pair of trochanteral depressor muscles"
- CONFIRMED | [body-mass-mean] The body mass stays at Burrows' measured mean, 12.3 mg. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): 12.3 +/- 0.7 mg (mean +/- s.e.m., n = 11); BODY_MASS = 12.3e-6 in the page script
- CONFIRMED | [variable-inputs] The three uncertain or variable terms remain in your hands. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): energy, launch time and muscle fraction are the three sliders; body mass is a constant
- CONFIRMED | [density-definition] Energy divided by launch time and jumping-muscle mass. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): updateBudget: density = e / t / muscleMass, muscleMass = BODY_MASS x fraction
- CONFIRMED | [comparison-ratios] The lower ratio uses 500 W/kg. The upper uses 250 W/kg. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): ratioLow = density / MUSCLE_HIGH (500); ratioHigh = density / MUSCLE_LOW (250)
- CONFIRMED | [brief-range] The brief's proposed 10-100× range does not survive its own central assumptions. | git show 67088387e0:research/the-spring-the-muscle-cant-match/codex/BRIEF.md | N2-claude.md reread (checker evidence retained): BRIEF.md lines 114, 117, 123 propose "~10-100x"; the verifier gives 72.4-295.6x
- CONFIRMED | [derived-band] At the measured 11% muscle fraction, Burrows' average and best energy estimates produce a comparison range of about 72-296×. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): verifier asserts 72.43 (49 uJ / 500) and 295.64 (100 uJ / 250); hand check 36,216/500 = 72.4, 73,910/250 = 295.6
- CONFIRMED | [larger-result-visible] The calculator does not hide that larger result. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): "Burrows best" preset shows 73,910 W/kg and "148-296x" (page script run under a stub DOM (N2-claude/tools/runpage.js) printed)
- CONFIRMED | [band-not-universal] It also does not turn the 250-500 W/kg band into a universal hard wall. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): band drawn as a range (MUSCLE_LOW 250, MUSCLE_HIGH 500) and the next sentence lists what moves it
- CONFIRMED | [energy-versus-power-1] Power is not energy. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring | N2-codex.md and N2-claude.md reread (checker evidence retained): Glossary, Power: "Energy of movement per unit time"
- CONFIRMED | [energy-versus-power-2] A muscle can supply the energy if it is allowed to work for longer. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "muscular force must be generated by a slow contraction in advance of the movement, storing energy which is then released rapidly"
- CONFIRMED | [energy-versus-power-3] What it cannot do is supply that work directly through the feet in one millisecond. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "could not be produced by direct muscle contractions over the short distances and brief time available"
- CONFIRMED | [energy-versus-power-4] The escape is to move the work earlier. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "generated by a slow contraction in advance of the movement"
- CONFIRMED | [loading-mechanism-1] The froghopper contracts its trochanteral depressor muscles while the legs remain cocked. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): "In preparation for a jump, the muscle contracts for a few seconds without depressing its trochanter"
- CONFIRMED | [loading-mechanism-2] A cuticular locking geometry prevents early motion. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "A ridge on the dorsal femur rides over and engages in front of a lateral and ventral protrusion of a coxa, forming a novel locking mechanism"; BMC: "mechanical 'latches' on the coxa and femur release"
- CONFIRMED | [loading-mechanism-3] Elastic structures in the thorax store the work. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): pleural arches of the metathorax are "bow-shaped composites" that "store energy"
- CONFIRMED | [loading-mechanism-4] Release turns a long, low-power loading phase into a short, high-power launch. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): muscle "contracts for a few seconds"; take-off in under 1 ms (Burrows 2003); Burrows 2006: legs "stay motionless for 1-2 s"
- CONFIRMED | [slow-shortening] Slow shortening keeps force high and spreads the work through time. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring | N2-codex.md and N2-claude.md reread (checker evidence retained): "spring-driven systems are typically loaded with muscles operating slowly with high force, not with high power" (WebFetch of the publisher page)
- CONFIRMED | [femur-coxa-lock] A femur-coxa lock holds the cocked leg while elastic energy accumulates. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): femoral ridge engages the coxal protrusion, "restraining a hind leg so that it is poised to extend"; "A hind leg does not move in this cocked position"
- CONFIRMED | [spring-timescale] The stored work leaves on the spring's timescale, decoupled from muscle speed. | https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "the bow decouples the arm muscles from the arrow's launch, such that the muscles need not contract quickly"; "For spring-driven actuation, takeoff velocity is not limited by the motor when the projectile mass is low"
- CONFIRMED | [later-pleural-arches] Later anatomical work describes the paired pleural arches as important elastic structures. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): "the bilaterally paired pleural arches of froghoppers are bow-shaped composites of stiff chitinous cuticle and elastic resilin"; "these bows are deformed so that they have the potential to store energy"
- CONFIRMED | [not-only-resilin] That does not justify reducing every jumping insect to a “resilin spring.” | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): Abstract: "the resilin itself could only store 1% to 2% of the energy required for jumping. The stiffer cuticular parts of the pleural arches could, however, easily meet all the energy storage needs"
- CONFIRMED | [composite-spatial-specific] The actual elastic system is composite, three-dimensional, and species-specific. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): composite of chitin and resilin; bow 1.5 x 0.7 x 0.5 mm; Discussion contrasts fleas ("some species of flea lacking pleural arches can still jump")
- CONFIRMED | [force-velocity-load-2] A preloaded spring does not share the motor's speed limit. | https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "For spring-driven actuation, takeoff velocity is not limited by the motor when the projectile mass is low"
- CONFIRMED | [force-velocity-load-3] As the load grows, inertia slows both routes and the spring's peak-power advantage disappears. | https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): Fig. 2: "At larger sizes, the motor-driven system performs moderately better than the spring-driven system"; large masses "are constrained by their inertial loads"
- CONFIRMED | [model-routes-1] The red route is a Hookean spring released from a latch. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): the coral (#e8674f) panel titled "SPRING RELEASE" plots F*sqrt(Fd/m)*sin*cos, release of a preloaded Hookean spring
- CONFIRMED | [calibration-1] Declared calibration: at the 12.3 mg reference mass, this toy model assigns Burrows' reported 49 µJ average jump energy to the ideal spring. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): MODEL_REF_SPRING_ENERGY = REPORTED_AVERAGE_JUMP_ENERGY = 49e-6; verifier release_energy_uJ 49.000
- CONFIRMED | [calibration-2] It also repurposes his 34 mN average external launch-force estimate, calculated as body mass times average acceleration, as both the motor's stall force and the Hookean spring's peak force. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): MODEL_REF_PEAK_FORCE = REPORTED_AVERAGE_EXTERNAL_FORCE = 0.034; Burrows: "The force (mf) exerted in an average jump is 34 mN" with f the acceleration (12.3 mg x 2,800 m/s2 = 34.4 mN)
- CONFIRMED | [force-not-measured-peak] The 34 mN value is not a measured peak spring force. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "The force (mf) exerted in an average jump is 34 mN": mass times average acceleration, a calculation, not a measured spring force
- CONFIRMED | [calibration-4] Giving both routes the same force scale makes their comparison legible, but it is a free modelling choice. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): the shared force scale is a constant the code sets, not a measured input
- CONFIRMED | [calibration-5] It sets the reference stroke to 2E/F = 2.88 mm and the spring stiffness to 11.80 N/m. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): REF_STROKE = 2 x 49e-6 / 0.034 = 2.882 mm; stiffness 11.796 N/m (verifier output)
- CONFIRMED | [size-scaling-1] The slider is logarithmic. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): body-mass input min -3 max 8, mass = 10^value mg
- CONFIRMED | [size-scaling-2] The model scales force with length², stroke and unloaded speed with length, and mass with length³. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): modelAt: scale = cbrt(mass/BODY_MASS); force x scale^2; stroke and vmax x scale
- CONFIRMED | [default-model-status] At 12.3 mg, this ideal spring model reaches 70.9 times the direct motor's peak power. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): verifier amplification 70.9319; page script run under a stub DOM (N2-claude/tools/runpage.js) printed "reaches 70.9 times"
- CONFIRMED | [curves-update] Loading and release power curves update with the chosen mass. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): updateModel calls drawPowerCurves(currentModel) on each slider input
- CONFIRMED | [crossover-model-specific] The live crossover is a consequence of this page's declared scaling rules and calibration. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): findCrossover bisects the page's own modelAt; 4.38965 kg
- CONFIRMED | [ilton-model-family] Ilton and colleagues used a family of motor, spring, and latch models to establish the general transition, not one universal animal mass. | https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): motor alone vs spring preloaded by the same motor across projectile masses, then nonideal springs and latches; motor Fmax 20 N, vmax 5 m/s, not an animal
- CONFIRMED | [sutton-height-tension] A later model by Sutton and colleagues asked a different question, jump height rather than peak power, and included a cost this ideal spring omits: muscle length-tension limits on how much work can be loaded. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC6907395/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): Abstract: "muscle length-tension properties limit spring-actuated systems to generating a maximum one-third of the possible work"; the comparison is jump height
- CONFIRMED | [sutton-2-5g] Their model put its crossover below about 2.5 g. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC6907395/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): "For masses >2.5 g ... muscle-actuated system is higher ... At masses <2.5 g, however, there is a 'crossover point'"; the page tracks the source's "<2.5 g" wording
- CONFIRMED | [not-animal-prediction] The number here is therefore a showing of the mechanism and its dependence on assumptions, not a prediction that every animal below 4.39 kg should latch its jump. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): 4.39 kg comes from the declared calibration and scaling; Sutton's model gives about 2.5 g, so the hedge is apt
- CONFIRMED | [large-animal-tendons] Large animals also use elastic tendons. | https://api.crossref.org/works/10.1111/j.1469-7998.1985.tb04944.x | N2-codex.md and N2-claude.md reread (checker evidence retained): Alexander, Dimery and Ker 1985 abstract: "an aponeurosis in the back as an important elastic strain energy store in galloping" in fallow deer and dogs
- CONFIRMED | [deer-elastic] Deer are not “spring-free.” | https://api.crossref.org/works/10.1111/j.1469-7998.1985.tb04944.x | N2-codex.md and N2-claude.md reread (checker evidence retained): same abstract (Crossref copy; publisher page 403): fallow deer store elastic strain energy in a back aponeurosis
- CONFIRMED | [one-kg-documentation] The narrower observation is that animals above about 1 kg are not documented as launching whole-body jumps primarily from a latched spring. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC6907395/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): "to the authors' knowledge there is no documentation of organisms >1 kg that are primarily spring-actuated"
- CONFIRMED | [mixed-actuation] Frogs and many other jumpers can mix muscle and elastic actuation. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC6907395/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): "the jump speeds and elastic recoil rates of frogs give them an opportunity for muscles and springs to actuate the jump simultaneously"
- CONFIRMED | [check-method-1] The budget and kinematic results below are recomputed in this browser from Burrows' reported inputs. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): updateBudget and fillChecks compute every budget and kinematic line from BODY_MASS, 2.8, 4, 0.001 s and 0.11
- CONFIRMED | [check-method-2] The toy-model outputs follow from the separately stated 49 µJ and repurposed 34 mN calibration plus the minimal equations, not from measured spring or motor parameters. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): model inputs are 49e-6 J, 0.034 N, 500 W/kg and 0.11; no measured spring or motor parameter
- CONFIRMED | [check-method-3] The independent Node verifier repeats the arithmetic and integrates the spring-release ODE from scratch. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): rk4Step + integrateSpringRelease (40,000 steps) reproduce 49.000 uJ and 1.604 ms; arithmetic repeated with its own constants
- CONFIRMED | [measured-inputs-list] Measured inputs: Burrows reports body mass 12.3 ± 0.7 mg, mean speed 2.8 ± 0.1 m/s, best speed 4 m/s, less than 1 ms leg extension, energies of 49 and 100 µJ, and jumping-muscle mass near 11% of body mass. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): 12.3 +/- 0.7 mg; 2.8 +/- 0.1 m/s; best 4 m/s; "less than 1 ms"; "49 microjoules, with the best jumps needing 100" uJ; "About 11% (n = 5)"
- CONFIRMED | [sampling-rounding] These are observations with sampling and rounding, not mathematical constants. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): every figure is a mean +/- s.e.m. with n (11, 5) or a rounded best value
- CONFIRMED | [range-declaration] Muscle comparison band: 250-500 W/kg is deliberately a range. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): MUSCLE_LOW = 250, MUSCLE_HIGH = 500, both ends shown
- CONFIRMED | [bird-power] Bird flight measurements reach about 471 W/kg in a maximal burst, and other preparations and definitions give different values. | https://journals.biologists.com/jeb/article/214/3/452/33507/Scaling-of-mechanical-power-output-during-burst | N2-codex.md and N2-claude.md reread (checker evidence retained): Jackson and Dial 2011 (JEB 214:452): "The maximum muscle-mass-specific power recorded was 471 W kg-1 in GRJA (mean=350 W kg-1)"; "in a single wingbeat" of burst escape flight
- CONFIRMED | [high-edge-comparison] Even the generous edge remains far below the froghopper launch requirement under the central assumptions. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): 36,216 W/kg / 500 = 72x; 73,910 / 500 = 148x
- CONFIRMED | [diagnostic-normalization] Power-density inference: dividing external launch power by jumping-muscle mass is a diagnostic test for power amplification. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring | N2-codex.md and N2-claude.md reread (checker evidence retained): Box 1: "The maximum (sometimes calculated as peak instantaneous) power output of the movement is divided by the mass of the muscle(s) that ... loads energy into a spring"; null hypothesis "that muscle directly generates the observed power output"
- CONFIRMED | [diagnostic-not-material-power] It is not the spring's own material power density and does not mean the muscle produces that instantaneous output. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring | N2-codex.md and N2-claude.md reread (checker evidence retained): "muscle power densities for latch-mediated spring actuation (LaMSA) systems are based on dividing by the 'wrong' actuator in order to infer power amplification relative to muscle"
- CONFIRMED | [check-calibration-1] Toy-model calibration: the model combines the reported 49 µJ average jump energy with the 34 mN average external launch-force estimate. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): 49e-6 J and 0.034 N are the two calibration constants
- CONFIRMED | [check-calibration-2] It repurposes that average force as both motor stall force and ideal spring peak force. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): MODEL_REF_PEAK_FORCE serves as motor stall force (modelAt force) and spring peak force (k = F/d)
- CONFIRMED | [burrows-force-definition] Burrows did not measure a 34 mN peak spring force. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): 34 mN is "The force (mf) exerted in an average jump", computed from mass and acceleration
- CONFIRMED | [check-calibration-4] This choice drives the baseline 48.0 mW spring peak, 70.9× amplification, 1.60 ms release, and 4.39 kg crossover. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): amplification = 2*sqrt(2E/m)/vmax with vmax proportional to 1/F, so spring peak, amplification, release time (pi/2*sqrt(2Em)/F) and crossover all scale with the 34 mN choice; verifier 47.985 mW, 70.93x, 1.604 ms, 4.390 kg
- CONFIRMED | [free-model-choices-1] Free model choices: the size model also uses a linear force-velocity motor, a massless ideal Hookean spring, no drag, no gravity during launch, no gearing, perfect latching, perfect energy transfer, 11% muscle at every size, geometric similarity, and a 500 W/kg motor calibration. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): modelAt/integrators: linear F-v motor, massless Hookean spring, no gravity or drag terms, 0.11 fixed, cbrt geometric scaling, MODEL_MUSCLE_POWER = 500
- CONFIRMED | [free-model-choices-2] The toy-model outputs belong to this full set of choices. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): outputs are pure functions of those constants
- CONFIRMED | [anatomy-summary-1] Anatomy: the froghopper uses a cuticular elastic system associated with the pleural arches and a cocking lock. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): pleural arches as the elastic store; Burrows 2003 femur-coxa lock
- CONFIRMED | [anatomy-summary-2] The exact distribution of strain and the contribution of resilin, stiff cuticle, and tendon should not be collapsed into one universal material claim. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): resilin "could only store 1% to 2%"; cuticle stores most; Burrows 2003 left cuticle or tendon open
- CONFIRMED | [machine-command] Machine check: node research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): downloaded from https://artwaste.land/checks/research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs (200, byte-identical), node exit 0, PASS
- CONFIRMED | [citation-1] Malcolm Burrows, “Froghopper insects leap to new heights,” Nature 424 (2003), 509. | https://api.crossref.org/works/10.1038/424509a | N2-codex.md and N2-claude.md reread (checker evidence retained): Crossref: Malcolm Burrows, Nature 424(6948) 509, 2003-07-31
- CONFIRMED | [citation-2] Malcolm Burrows, “Jumping performance of froghopper insects,” Journal of Experimental Biology 209 (2006), 4607-4621. | https://api.crossref.org/works/10.1242/jeb.02539 | N2-codex.md and N2-claude.md reread (checker evidence retained): Crossref: Malcolm Burrows, J Exp Biol 209(23) 4607-4621, 2006
- CONFIRMED | [citation-3] Malcolm Burrows, Stephen R. Shaw, and Gregory P. Sutton, “Resilin and chitinous cuticle form a composite structure for energy storage in jumping by froghopper insects,” BMC Biology 6 (2008), 41. | https://api.crossref.org/works/10.1186/1741-7007-6-41 | N2-codex.md and N2-claude.md reread (checker evidence retained): Crossref: Malcolm Burrows; Stephen R Shaw; Gregory P Sutton, BMC Biol 6, 41, 2008. The tool's DOI MISMATCH (initials) is a false alarm
- CONFIRMED | [citation-4] Mark Ilton and colleagues, “The principles of cascading power limits in small, fast biological and engineered systems,” Science 360 (2018), eaao1082. | https://api.crossref.org/works/10.1126/science.aao1082 | N2-codex.md and N2-claude.md reread (checker evidence retained): Crossref: first author Mark Ilton, Science 360(6387) eaao1082, 2018
- CONFIRMED | [citation-5] Gregory P. Sutton and colleagues, “Why do Large Animals Never Actuate Their Jumps with Latch-Mediated Springs?” Integrative and Comparative Biology 59 (2019), 1609-1618. | https://api.crossref.org/works/10.1093/icb/icz145 | N2-codex.md and N2-claude.md reread (checker evidence retained): Crossref: first author Gregory P Sutton, ICB 59(6) 1609-1618, 2019. Title shortened: full title ends "? Because They can Jump Higher Without Them". Tool MISMATCH on initials is a false alarm
- CONFIRMED | [reference-description-1] This is the primary source for the 12.3 mg Philaenus spumarius measurements, the 2.8 and 4 m/s speeds, the less-than-1 ms launch, the 49 and 100 µJ energies, the 11% muscle estimate, and the locking-mechanism interpretation. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): all six items are on p. 509, plus the femoral-ridge locking mechanism
- CONFIRMED | [reference-description-2] The later five-species study used faster imaging, reported a best Philaenus takeoff of 4.7 m/s in 0.875 ms, and described variation across froghopper species. | https://journals.biologists.com/jeb/article/209/23/4607/16474/Jumping-performance-of-froghopper-insects | N2-codex.md and N2-claude.md reread (checker evidence retained): Abstract: images "at rates up to 8000 s-1"; "In the best jumps by Philaenus, take-off occurs within 0.875 ms ... at a peak velocity of 4.7 m s-1"; Methods: "Five species of froghoppers were analysed"; best take-off "ranged from 4.6 m s-1 in Lepyronia to 3.4 m s-1 in Aphrophora"
- CONFIRMED | [reference-description-3] This is the direct anatomical and mechanical evidence for the paired pleural arches as composite elastic stores. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC2584104/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): pleural arches as composite chitin-resilin stores, with stimulation and energy calculations
- CONFIRMED | [reference-description-4] This supplies the general motor-spring-latch framework, the linear motor force-velocity starting point, and the mass-dependent transition. | https://www.hmc.edu/physics/wp-content/uploads/sites/22/2023/02/pub-117.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): "A linear force-velocity relation for the motor"; motor vs spring across projectile mass; "key transition"
- CONFIRMED | [reference-description-5] This adds muscle length-tension limits and demonstrates why a crossover depends on the performance question and model. | https://www.ebi.ac.uk/europepmc/webservices/rest/PMC6907395/fullTextXML | N2-codex.md and N2-claude.md reread (checker evidence retained): length-tension limit on stored work (28%, about one-third); crossover location moves with the effects it lists
- CONFIRMED | [reference-description-6] This is the source for the diagnostic logic and its limitations. | https://journals.biologists.com/jeb/article/222/15/jeb197889/223378/Beyond-power-amplification-latch-mediated-spring | N2-codex.md and N2-claude.md reread (checker evidence retained): Box 1 sets out the diagnostic and the 'wrong actuator' limitation
- CONFIRMED | [closing-energy] The muscle pays for the jump. The spring changes when the bill comes due. | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-codex.md and N2-claude.md reread (checker evidence retained): metaphor consistent with "force generated before the jump to be released rapidly"
- CONFIRMED | [placard-1] This layer's check works the answer out again from scratch, independently of this page. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): only import is node:assert/strict; no file or network reads
- CONFIRMED | [placard-3] It can settle the finding; it cannot notice a figure that drifted on this page. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): it reads nothing from the page, so a drifted page figure cannot fail it
- CONFIRMED | [placard-4] It is published, and it runs on its own: one file, and Node. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): published at /checks/... (200, 13,194 bytes, identical to the repo); node exit 0 with no other files
- CONFIRMED | [static-power-density] Required launch power density 36,216 W/kg Energy divided by launch time and jumping-muscle mass. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 36,216 W/kg (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-ratio-band] Compared with 250-500 W/kg 72-145× The lower ratio uses 500 W/kg. The upper uses 250 W/kg. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 72-145x (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-spring-peak] Spring peak 48.0 mW | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 48.0 mW (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-direct-peak] Direct motor peak 0.677 mW | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 0.677 mW (script writes 676.5 uW, same value) (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-amplification] Amplification 70.9× | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 70.9x (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-crossover] Model crossover 4.39 kg | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 4.39 kg (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-load-time] Load to 99% 167 ms | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 167 ms (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-release-time] Ideal release 1.60 ms | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 1.60 ms (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-live-equation] P = E / (t × mbody × fmuscle) | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: replaced by the filled equation at load (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-model-equation] motor: F = Fmax(1 - v/vmax) / spring: m x'' = k(d - x) | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: matches the integrated equations (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-check-budget] 49 µJ / (1.00 ms × 1.353 mg) = 36,216 W/kg | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 49/(1.00 ms x 1.353 mg) = 36,216 W/kg (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-check-kinematics] 49 µJ implies 2.82 m/s for a 12.3 mg body. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: sqrt(2 x 49e-6 / 12.3e-6) = 2.823 m/s (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-load-caption] loading uses its own 0-167 ms axis | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 0-167 ms (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [static-release-caption] release uses its own 0-1.60 ms axis | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): fallback text equals what the script writes at load: 0-1.60 ms (page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same)
- CONFIRMED | [generated-default-live-equation] P = 49 µJ / (1.00 ms × 12.3 mg × 11.0%) = 36,216 W/kg | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-default-check-kinematics] 49 µJ implies 2.82 m/s, 2,823 m/s², 34.7 mN, and 288 g for a 12.3 mg body. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-default-check-average] ½ × 12.3 mg × (2.8 m/s)² = 48.22 µJ; 35,636 W/kg; 71.3-142.5×. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-default-check-best] ½ × 12.3 mg × (4.0 m/s)² = 98.40 µJ; 72,727 W/kg; 145.5-290.9×. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-default-check-ode] 49 µJ plus repurposed 34 mN: k = 11.80 N/m; peak = 48.0 mW; quarter-cycle release = 1.60 ms; amplification = 70.93×. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed the same; hand check k = 0.034/0.0028824 = 11.80 N/m, 0.5 x 0.034 x sqrt(2 x 49e-6/12.3e-6) = 48.0 mW, pi/2 x sqrt(12.3e-6/11.796) = 1.604 ms
- CONFIRMED | [generated-default-check-cross] Bisection on Pspring / Pmotor = 1 gives 4.39 kg for the declared scaling choices. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-default-curve-summary] At 12.3 mg, motor loading takes 167 ms to reach 99 percent compression. Ideal spring release takes 1.60 ms. Spring peak power is 48.0 mW, versus 676.5 µW for direct motor drive. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-best-check-budget] 100 µJ / (1.00 ms × 1.353 mg) = 73,910 W/kg | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-best-check-kinematics] 100 µJ implies 4.03 m/s, 4,032 m/s², 49.6 mN, and 411 g for a 12.3 mg body. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [generated-large-model-status] At 100.0 kg, the spring has no peak-power advantage in this model. Direct motor peak is 2.00 times higher. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed at slider 8 (100 kg): amplification 0.50, "Direct motor peak is 2.00 times higher"
- CONFIRMED | [generated-large-curve-summary] At 100.0 kg, motor loading takes 167 ms to reach 99 percent compression. Ideal spring release takes 323 ms. Spring peak power is 1.94 kW, versus 3.89 kW for direct motor drive. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed this exact string
- CONFIRMED | [control-energy] Jump energy 49 µJ 20 µJ 140 µJ | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): energy range min 20 max 140, default 49
- CONFIRMED | [control-launch-time] Launch time 1.00 ms 0.50 ms 1.50 ms | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): min 0.5 max 1.5, default 1
- CONFIRMED | [control-muscle-fraction] Jumping muscle 11.0% 5% body mass 20% | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): min 5 max 20, default 11
- CONFIRMED | [control-body-mass] 0.001 mg 100 kg | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): range -3..8 log mg = 0.001 mg..100 kg
- CONFIRMED | [markdown-body-1] An immersive, operable layer. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): standalone interactive page
- CONFIRMED | [markdown-body-2] The standalone page at the `href` above computes a froghopper's launch power density from measured energy, launch time, body mass, and an exposed jumping-muscle fraction. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): updateBudget uses energy, time, BODY_MASS and fraction
- CONFIRMED | [markdown-body-3] A second instrument integrates a minimal motor-spring-latch model and lets the reader move a geometrically scaled inertial load through the model-specific crossover where the spring loses its peak-power advantage. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): modelAt, findCrossover and the mass slider
- CONFIRMED | [markdown-body-4] The page keeps observed kinematics, diagnostic inference, and toy-model output separate. | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): separate sections: measured inputs, power-density inference, toy-model calibration
- CONFIRMED | [markdown-body-5] Its independent Node verifier recomputes the reported energies and power-density bands, integrates the loading and release equations, and solves the crossover from scratch. | git show 67088387e0:research/the-spring-the-muscle-cant-match/verify-the-spring-the-muscle-cant-match.mjs | N2-claude.md reread (checker evidence retained): kinematics, powerDensity, integrateSpringRelease, integrateMotorLoading, findCrossover
- CONFIRMED | [related-as-hangs-the-chain] Both turn a familiar curve or movement into a live mechanics instrument. One follows gravity into a hanging chain, while this one follows stored work into a millisecond launch. | git show 67088387e0:src/content/strata/as-hangs-the-chain.md | N2-claude.md reread (checker evidence retained): that layer's dek: hanging chain, catenary, live instruments
- CONFIRMED | [related-the-quickest-way-down] Two studies of time as the hidden variable in mechanics. The brachistochrone wins by redistributing acceleration along a path; the froghopper wins by moving muscle work to before takeoff. | git show 67088387e0:src/content/strata/the-quickest-way-down.md | N2-claude.md reread (checker evidence retained): brachistochrone dek: cycloid wins
- CONFIRMED | [related-not-forty-five] Companion corrections to simple jump stories. One shows why a body's best projectile angle need not be 45 degrees, while this one shows why the power source need not act during launch. | git show 67088387e0:src/content/strata/not-forty-five.md | N2-claude.md reread (checker evidence retained): that layer's dek: best human launch angle is not 45 degrees
- CONFIRMED | [related-fern] Two living launchers separate slow energy loading from fast release. | git show 67088387e0:src/content/strata/the-catapult-under-the-fern.md | N2-claude.md reread (checker evidence retained): relation note in the-catapult-under-the-fern.md matches
- CONFIRMED | [publication-date] "datePublished":"2026-07-23" | git show 67088387e0:src/content/strata/the-spring-the-muscle-cant-match.md | N2-claude.md reread (checker evidence retained): frontmatter date: 2026-07-23
- CONFIRMED | [size-plot-interpretation] left: smaller load, larger advantage | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): amplification falls as mass rises across the plotted range
- CONFIRMED | [size-plot-equality] horizontal line: equal peak power | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): ratio 1 gridline drawn in #71c7c2
- CONFIRMED | [load-stage-name] Slow loading, fast release | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): 167 ms load vs 1.60 ms release at the default mass
- CONFIRMED | (added) Preset buttons "Burrows average" and "Burrows best" set 49 uJ and 100 uJ at 1.00 ms and 11% | https://www.olin.edu/sites/default/files/froghopper-burrows.pdf | N2-claude.md reread (checker evidence retained): "The energy (0.5mv2) required for an average jump is 49 microjoules, with the best jumps needing 100" uJ, "conservatively applied in 1 ms", 11% muscle (index.html lines 527-528 and the click handlers)
- CONFIRMED | (added) The muscle band and needle on the power scale: band 250-500 W/kg at 13.3%-23.3%, needle at 85.3% for 36,216 W/kg | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): page script run under a stub DOM (N2-claude/tools/runpage.js) printed band left 13.26% width 10.03%, needle 85.30%; log10 checks agree (the positions are right; only the tick labels are wrong)
- CONFIRMED | (added) Size-chart axes: mass ticks 1 ug, 1 mg, 1 g, 1 kg, 100 kg; ratio gridlines 1x, 10x, 100x, 1000x | git show 67088387e0:public/strata/the-spring-the-muscle-cant-match/index.html | N2-claude.md reread (checker evidence retained): drawSizeChart: xMin -9 = 10^-9 kg = 1 ug, xMax 2 = 100 kg; yFor log ratio; labels match their positions

## Findings

- [fixed] X1: Supplemented muscle-power-conditions with Longo Box 1 and three Jackson and Dial passages; the temperature quotation remains verbatim. No page correction line for this MINOR evidence repair.
- [fixed] X2: Changed the load description to approaching its motor's unloaded speed; added the matching 2026-10-14 correction in HTML and markdown.
- [fixed] X3: Identified the blue curve as motor loading and direct drive as the numerical peak readout; added the matching correction in both bodies, shared with K2.
- [fixed] X4: Supplemented crossover-other-assumptions with five located Sutton and Ilton passages. The original quotation remains verbatim; no page correction line for this MINOR repair.
- [fixed] X5: Changed Sheila N. Patek and colleagues to Sarah J. Longo and colleagues in the citation. Shared MINOR repair with K3, with no page correction line.
- [dated] X6: Set JSON-LD dateModified to 2026-10-14, preserving datePublished 2026-07-23. The three Corrected lines date this revision, satisfying the explicit metadata exception without an Updated line.
- [fixed] X7: Moved 500, 2500 and 12500 W/kg ticks from 25, 50 and 75 percent to 23.299, 46.598 and 69.897 percent. Added the matching correction in both bodies, shared with K5.
- [fixed] K1: Restored Burrows' conditional storage proposal with suggested that the energy could be stored. MINOR wording repair, with no page correction line.
- [fixed] K2: Answered by the same blue-curve prose fix and dated correction as X3; the duplicated checker report remains a separate WRONG claim line.
- [fixed] K3: Answered by the same Longo citation change as X5; retained the triage MINOR level and added no page correction line.
- [fixed] K4: Removed the plain-text README pointer. Local source and public file inventory establish the access defect; current uniform 403 responses are recorded as inconclusive about live availability. No page correction line for this MINOR repair.
- [fixed] K5: Answered by the same tick-position fix and dated correction as X7; the duplicated checker report remains a separate WRONG claim line.