Informativity Institute · Journalist brief

Gravity’s measurement mystery: the numbers behind MQ’s 35-ppm prediction

A reporting guide to the NIST/BIPM results, historical gravitational-constant comparisons, a 2021 correspondence record and a proposed controlled experiment.

Prepared November 5, 2026 · Experimental paper published April 16, 2026 · Review published September 8, 2025
Companion: Gravity’s numbers don’t agree. MQ predicts a 35-ppm split.

The numerical story: Measurement Quantization (MQ) gives a conditional separation of 34.9284 parts per million between two gravitational-coupling realizations. NIST’s copper configuration gives 56.79 ± 29.43 ppm between its free and electrostatic modes: compatible with MQ, but also only 1.93 standard uncertainties from zero. A four-pair historical fit gives 60.99 ± 26.93 ppm under its declared covariance model. Separately, two overlapping historical midpoint treatments lie +3.04 and −2.65 ppm from the frozen MQ midpoint, with uncertainties of 40.79 and 34.33 ppm. These are comparisons worth investigating, rather than an experimental confirmation of MQ.

What the independent publications actually say

The Newtonian gravitational constant, G, sets gravity’s strength. Precision experiments disagree more than their quoted uncertainties suggest. The 2026 NIST/BIPM paper opens by contrasting “new physics or unrecognized instrumental effects”; it explicitly calls new physics remote and instrumental systematics more plausible. MQ supplies a particular theoretical interpretation of that unresolved problem, developed by independent researcher Jody A. Geiger. [1] [2] [3]

Table 1 separates the external publications from the Institute’s interpretation. The review’s reference 154 is Geiger’s 2023 paper, Measurement quantization, International Journal of Geometric Methods in Modern Physics 20, 2350069; that citation is a public research trail rather than a statement that the review authors verified MQ. [2] [18]

Table 1: Three sources with different scientific roles
SourceVerified contributionScope
NIST/BIPM experimental paper · 2026Dual-mode measurements with copper and sapphire fibers; consensus (6.67387 ± 0.00038) × 10⁻¹¹ m³ kg⁻¹ s⁻².The authors investigate apparatus offsets; they do not claim to have tested or confirmed MQ.
Zhang and colleagues’ review · 2025Section 5.3 discusses Geiger’s approach to discrepancies in gravitational measurements and cites it as reference 154.The review also discusses other theoretical proposals and systematics. MQ is not its only beyond-systematics explanation.
MQ theory and current reanalysisAn upper-count/finite-count relation, a numerical mode-gap target, historical comparisons and an experiment proposal.The apparatus-mode assignment and retrospective statistical construction belong to the MQ account.

The two external papers provide a reporting connection, not a joint endorsement: one leaves a remote new-physics possibility open; the other documents MQ among approaches to the discrepancy. The BIPM apparatus itself has a long experimental history, so successive campaigns cannot automatically be treated as wholly independent replications. [1] [2] [4] [5]

What MQ means, and where 34.9284 ppm comes from

MQ starts from the axiom measure is discrete and proposes a common logical origin for physical laws through count relationships. Its current architecture distinguishes deriving an equation’s form from selecting the universe, state and units in which that equation is evaluated. The Internal Frame is the discrete count-configuration domain; the System Frame is its observable relational realization under the Frames mapping. The underlying count domain is not assumed to be a microscopic material lattice in a pre-existing continuous space. [19]

For this comparison, the operative claim is narrower: a finite-count electromagnetic realization of the gravitational coupling differs slightly from its upper-count-limit realization. Testing that contrast addresses a specified MQ consequence; it does not by itself verify the framework’s proposed derivation of all physical laws. [3] [6] [7]

Let the dimensionless coefficient 𝜃𝑠𝑖 specify the MQ calibration; let 𝑛𝐿 be the realized separation count, and 𝑄𝐿 the positive Diophantine realization residual. The calibrated count below is a positive real-valued realization; it is not a claim that this calibration value is itself an integer primitive count. The residual follows from the unit-side right-triangle relation. [6] [7]

𝑛𝐿=276𝜃𝑠𝑖,1+𝑛𝐿2=𝑛𝐿+𝑄𝐿2(1a)
𝑄𝐿=1+𝑛𝐿2−𝑛𝐿=11+𝑛𝐿2+𝑛𝐿(2b)

In the source convention used here, upright G denotes the upper-count-limit coupling and italic G the finite-count electromagnetic coupling; both have SI units m³ kg⁻¹ s⁻². Their ratio removes the common dimensional normalization. The target below uses the finite-count value as its denominator; “ppm” means the resulting dimensionless fraction multiplied by one million. [3] [6]

G=2𝑄𝐿𝑛𝐿G,δMQ=106(GG−1)=106(12𝑄𝐿𝑛𝐿−1)(3c)
Table 2: Current count-geometry calculation
QuantityCentral valueRole
Declared current θ calibration3.26239030504Dimensionless input to this calculation
Realized separation count84.6005456716276 divided by the declared coefficient
Positive residual0.005909920940206Stable reciprocal form of Equation (2b)
Finite-count / upper-count ratio0.999965072834481Twice the residual–count product
Predicted relative separation34.928385 ppmRounds to 34.9284 ppm, or 34.93 ppm in the release

Table 2 evaluates the current count relation; Table 3 preserves the historical edition used for the midpoint analysis. The dimensional normalization is upright G = c³tf/mf, where c is the speed of light and the source’s fundamental time and mass measures supply tf and mf. Multiplying this by twice the residual–count product gives the finite-count value. The normalization’s dimensions are (m s⁻¹)³ × s / kg = m³ kg⁻¹ s⁻². The complete realization and calibration chain is available in the linked preprint. [6] [7] [17]

The author identifies four inputs for the fundamental-measure/constant reconstruction: the fine-structure constant selects the dimensionless coefficient, the speed of light anchors realized length/time and SI units, and electron mass with Bohr radius supplies cross-dimensional normalization. These are declared universe/realization-selection roles, not four statistically independent observations or an assertion that measurement supplied the equation’s logical form. CMB temperature is separately an epoch selector and is not an extra input to the count-gap arithmetic above. The source-specific derivation must still establish each input’s actual role, and numerical uncertainty must retain shared CODATA dependence. The comparisons below treat the declared target as fixed without assigning an uncertainty for possible model discrepancy. [8] [17] [19]

Table 3: Keep historical and current numerical editions separate
Calculation snapshotFinite-count valueUpper-count valueMidpoint
Frozen book / historical comparison6.67384483626.67407794286.6739613895
Current public gravity-page central values6.67384483176.67407793836.6739613850

a All three numerical columns multiply 10⁻¹¹ m³ kg⁻¹ s⁻². The midpoint is the arithmetic mean of the two couplings. The historical difference is 2.331066 × 10⁻¹⁵ m³ kg⁻¹ s⁻². The central midpoint update is approximately −0.000674 ppm. Historical offsets below retain their frozen denominator; the current count calculation is identified separately. [6] [9]

The measured results and the denominator convention

In free-deflection operation, the torsion pendulum’s gravitationally driven motion is measured. In electrostatic-servo operation, electrical feedback supplies a balancing torque. Both modes still require geometry, optical readout and calibration. Associating free deflection with the MQ upper-count realization and servo with its finite-count realization is a retrospective MQ interpretation; it is not a statement made by the experimental collaboration. [1] [3]

Table 4: Published inputs used for the four-pair reconstruction
Campaign / configurationServo coefficientFree coefficientRelative u: servo / free (ppm)Within-pair ρ
BIPM Mark I · 20016.6755306.67565060 / 67-0.18
BIPM Mark II · corrected 20146.6751506.67586061 / 54-0.63
NIST copper · 20266.6736426.67402123.2 / 30.3+0.42
NIST sapphire · 20266.6726376.67363637.5 / 93.9+0.25

a Coefficients multiply 10⁻¹¹ m³ kg⁻¹ s⁻². Relative uncertainties are one-standard uncertainties. Corrected Mark II values replace the preliminary result affected by a known servo error. Inputs and their provenance are tabulated in the MQ technical reanalysis; the original experimental publications remain the measurement sources. [1] [3] [4] [5]

For context, the review reports MSL results of (6.6742 ± 0.0007) × 10⁻¹¹ in 1999 and (6.67387 ± 0.00027) × 10⁻¹¹ in 2003, in m³ kg⁻¹ s⁻². NIST’s 2026 consensus is (6.67387 ± 0.00038) × 10⁻¹¹ in the same units, with 57-ppm relative uncertainty. The matching rounded central values do not make these one result, nor are successive MSL publications automatically independent inputs. [1] [2]

The contrast uses the servo value as denominator. Let F and E denote free and servo coefficients. If their quoted relative standard uncertainties are rF and rE in ppm and their correlation is ρ, first-order propagation of the full quotient gives:

δ=106(FE−1),uδ=FErF2+rE2−2ρrFrE(4d)

Worked copper example. Substitution gives 10⁶ × (6.674021 / 6.673642 − 1) = 56.7906 ppm. Its uncertainty is (6.674021 / 6.673642) × √(30.3² + 23.2² − 2 × 0.42 × 30.3 × 23.2) = 29.4269 ppm. The distance from zero is 1.930 standard uncertainties; from the MQ target, 0.743. The two-sided Gaussian zero-gap p-value is approximately 0.0536. Compatibility with the target is not a detection of its mechanism. [1] [3] [10]

The frozen book calculation quotes 56.7889 ± 29.4252 ppm for copper; reconstructing the explicitly declared quotient from published rounded coefficients gives 56.7906 ± 29.4269 ppm. Both round to the release’s 56.79 ± 29.43 ppm. This brief uses the reproducible rounded-input reconstruction throughout the plots and fit. [3] [9]

Figure 1 puts all four Table 4 contrasts on one axis; the broad BIPM bars and copper’s stronger precision are visible without treating the fitted row as extra evidence.

measured mode gapsFour measured contrasts with one-standard-uncertainty bars, the fixed MQ target and a combined fit that reuses those measurements.Same-apparatus contrasts: free deflection minus electrostatic servoOne-standard-uncertainty bars • ppm relative to the servo result-100050100150200250MQ 34.9284BIPM Mark I · 200117.98 ± 97.66BIPM Mark II · corrected106.36 ± 103.87NIST · copper56.79 ± 29.43NIST · sapphire149.72 ± 92.01Four-pair GLS fit60.99 ± 26.93Mode separation (ppm); fitted row reuses the four measurements above
Figure 1. Reconstruction from Table 4 with correlated quotient propagation. The vertical target is conditional on the MQ mode assignment. The last row is a covariance-aware combination of the preceding four rows, not a fifth experiment. [1] [3] [4] [5]

How the four-pair fit handles shared uncertainty

The NIST paper’s correlation matrix, in order copper servo, copper free, sapphire servo, sapphire free, has off-diagonal entries 0.42, 0.38, 0.12, 0.23, 0.23 and 0.25. Multiplying these correlations by the corresponding absolute standard uncertainties constructs the four-result covariance. Propagating it through both quotient derivatives, ∂δ/∂F = 10⁶/E and ∂δ/∂E = −10⁶F/E², gives the two-mode covariance block below. The reconstruction assumes zero covariance between the two BIPM campaigns and between those campaigns and NIST; that assumption is not evidence that every inherited apparatus error is independent. [1] [3]

Table 5 gives the resulting contrast covariance; Table 6 reports the fitted weights and reconstructed contrasts. Equation labels in this brief identify its own calculation steps, rather than reproducing numbering from the original papers.

Table 5: Covariance of the four mode contrasts, in ppm²
Mark IMark IICopperSapphire
BIPM Mark I · 20019536.54290.00000.00000.0000
BIPM Mark II · corrected 20140.000010789.73490.00000.0000
NIST copper · 20260.00000.0000865.9419462.3295
NIST sapphire · 20260.00000.0000462.32958465.3692

For contrast vector d and covariance V, generalized least squares (GLS) estimates one common gap μ. The vector 1 has four unit entries. This is a model of a shared contrast; it does not establish that all four instruments realized exactly the same physical mode effect.

μ^=1TV−1d1TV−11,uμ^=(1TV−11)−12(5e)
Table 6: Reconstructed contrasts and GLS leverage
ConfigurationGap (ppm)Standard u (ppm)GLS weight
BIPM Mark I · 200117.976197.65527.605%
BIPM Mark II · corrected 2014106.3647103.87366.722%
NIST copper · 202656.790629.426981.560%
NIST sapphire · 2026149.715992.00744.113%
Common-gap estimate60.993226.9309100%

a The copper pair supplies about 81.56% of the estimator weight. The aggregate is strongly influenced by that pair, rather than four equally precise replications.

The fit is 60.9932 ± 26.9309 ppm, or 60.99 ± 26.93 ppm. The earlier frozen summary 60.994 ± 26.930 ppm differs only in final reconstruction digits. The residual χ² is 1.412 for three degrees of freedom. Zero lies 2.265 standard uncertainties below the fitted mean; the MQ target lies 0.968 below it. A two-sided Gaussian zero-gap test gives p ≈ 0.0235; a one-sided test gives half that value only if the positive direction was specified in advance. [3] [9]

Interpreting the 8.14-to-1 likelihood ratio

With the same fixed covariance for each candidate gap, χ²(μ) = (d − μ1)ᵀV⁻¹(d − μ1), and relative likelihood is exp[−(χ²(μ) − χ² at the fitted mean)/2]. Both fixed comparisons have no fitted gap parameter. Their ratio quantifies support inside this particular Gaussian model; it is neither a posterior probability nor odds that MQ is true.

Table 7 reports the numerical model comparisons; Figure 2 shows why both the MQ target and zero remain plausible locations on the broad likelihood curve.

Table 7: Conditional model comparisons
Model / comparisonCalculated quantityInterpretation
Zero common gapχ² = 6.541; relative likelihood 0.076945Reference conventional zero-contrast candidate, without an added offset model
Fixed MQ gapχ² = 2.349; relative likelihood 0.626030Theoretical target under the stated mode association
Fitted common gapχ² = 1.412; relative likelihood 1One additional fitted gap parameter
MQ / zero8.14 to 1Conditional likelihood ratio
Fitted gap / MQ1.60 to 1Raw likelihood improvement from allowing a fitted gap
AIC and BIC, MQ / fitted gap1.70 and 1.25 to 1Illustrative penalized relative support; BIC uses nominal n = 4
common gap likelihoodRelative Gaussian likelihood for the four-pair common gap, with markers at zero, the MQ target and the fitted maximum.Conditional likelihood of a common mode gapPrimary quoted budgets and declared covariance; extra unknown offsets excluded020406080100120140Zero: 0.077MQ: 0.626Best fit: 1.000Common gap (ppm); likelihood normalized to the fitted maximum
Figure 2. Gaussian common-gap likelihood normalized at its fitted maximum. It visualizes the same four contrasts, with no additional data. AIC penalizes one fitted parameter by 2; BIC uses ln(4). Small, correlated samples limit broad evidential interpretations of those penalties. [3] [11] [12]

The book also reports a roughly 5.4-to-1 comparison after introducing additional heterogeneity. Its precise extra-variance model and fitting inputs are not supplied in the materials reviewed here, so that figure is not regenerated or used as this brief’s main result. NIST’s published consensus separately allows configuration-specific additional “dark uncertainty”—an uncertainty treatment, not dark matter. Adding plausible unknown offsets can weaken discrimination between fixed gaps. [1] [9]

The primary NIST uncertainty budgets contain substantial conventional terms: autocollimator nonlinearity reaches 85.7 ppm for sapphire free deflection, while mass integration contributes 16.2 ppm to each configuration. The paper investigates unknown torque offsets, including possible resistive-heating effects. A remaining mode difference is not evidence that these effects have been eliminated. [1]

The historical ±3.5-ppm graphic, with the full uncertainty

The useful historical comparison is the midpoint between the two MQ coupling realizations, not an independently observed 35-ppm split. Chapter 7 of The Rules Beneath Reality and the Institute’s experimental page give two aggregate historical treatments: a base analysis and an expanded analysis including MSL. Their central offsets are +3.04 and −2.65 ppm. A ±3.5-ppm display window contains both centers; it is not their measured uncertainty, and the values are not exactly ±2.5 ppm. [9] [13]

historical midpoint offsetsUpper panel magnifies central offsets of plus 3.04 and minus 2.65 ppm. Lower panel shows uncertainties of 40.79 and 34.33 ppm for the same overlapping historical treatments.Historical midpoints: close central values, broad uncertaintiesA · Central offsets only (uncertainty bars shown in panel B)-3.5-2023.5Base treatment+3.04 ppmIncluding MSL-2.65 ppmB · Same estimates with one-standard-uncertainty bars-100-50050100Base treatment+3.04 ± 40.79 ppmIncluding MSL-2.65 ± 34.33 ppmOffset from frozen MQ midpoint (ppm)Overlapping historical treatments; these are not two independent determinations of a mode split.
Figure 3. Panel A magnifies the central offsets within a ±3.5-ppm window. Panel B restores the one-standard-uncertainty bars on a common scale. The two treatments overlap in their underlying evidence; they must not be counted as independent confirmations. The target midpoint is treated as fixed. [9] [13]

Use the frozen midpoint M₀ = (6.6738448362 + 6.6740779428)/2 = 6.6739613895, in coefficient units of 10⁻¹¹ m³ kg⁻¹ s⁻². For a reported historical midpoint M with standard uncertainty u, calculate its fractional offset, uncertainty in ppm and standardized residual as follows:

r=106M−M0M0,ur=106uM0,z=M−M0u(6f)
Table 8: Historical midpoint arithmetic
TreatmentMidpoint coefficient ± uOffset (ppm)u (ppm)Residual zTwo-sided p
Base historical treatment6.67398168 ± 0.00027223+3.04024840.7899+0.0745340.9406
MSL-inclusive treatment6.67394370 ± 0.00022912-2.65052534.3304-0.0772060.9385

a Coefficients multiply 10⁻¹¹ m³ kg⁻¹ s⁻². The p-values describe compatibility with a fixed midpoint under a Gaussian approximation; they are not probabilities that MQ is correct.

For the base treatment, the subtraction is 6.67398168 − 6.6739613895 = 0.0000202905; dividing by the frozen midpoint and multiplying by one million gives +3.040248 ppm. For the expanded treatment, 6.67394370 − 6.6739613895 = −0.0000176895 gives −2.650525 ppm. At those small standardized residuals, fixing the center to MQ retains approximately 99.72% and 99.70% of each Gaussian curve’s maximum likelihood. That high compatibility reflects their broad uncertainties and does not measure a theory’s chance of being true.

What can be reconstructed from the historical record

The MQ interpretation separates gravitational results by their physical measurement route, including electromagnetic versus macroscopic realization, then compares the midpoint of the resulting group estimates with MQ. If the two group means are μE and μM with covariance C, their midpoint and variance are:

M=μE+μM2,u2(M)=CEE+2CEM+CMM4(7g)

A reproducible population fit would supply each experiment’s value, inclusion rule, group assignment, revised/corrected status and full covariance. Given a membership design matrix A, individual-value vector g and their covariance Σ, the group estimator is (AᵀΣ⁻¹A)⁻¹AᵀΣ⁻¹g and its covariance is (AᵀΣ⁻¹A)⁻¹. The reviewed book and public summary supply the aggregate midpoints above, but not that complete per-experiment classification and covariance file. Thus Table 8 reproduces the downstream midpoint arithmetic; it does not independently rebuild the original historical population analysis. That underlying file should be requested before describing the grouping as independently replicated. [9] [13]

A midpoint match alone cannot establish two distinct populations or determine their separation. Absolute coupling values also remain a constraint: the corrected BIPM Mark II combined value, (6.67554 ± 0.00016) × 10⁻¹¹ m³ kg⁻¹ s⁻², lies about 9.14 quoted standard uncertainties above the current MQ upper-count central value, ignoring any MQ model-discrepancy allowance. Agreement of a mode contrast does not resolve that absolute-value tension. [3] [5] [6]

The human record: a dated message, then a later mode interpretation

Geiger’s preserved message to NIST contacts has an embedded sent date of September 26, 2021, 3:11 p.m. It describes different electromagnetic and macroscopic measurement routes and asks about the physical interpretation of the 2018 CODATA gravitational constant. The screenshot’s date governs this reproduction; a September 21 date appearing in a secondary narrative is not substituted for it. [9] [14]

Table 9 distinguishes the correspondence, theoretical publication, external citation and experimental publication. Figure 4 preserves the supplied message image with a selected accessible transcription below it.

Table 9: Dates and what they establish
Date / stageRecordReporting significance
September 26, 2021Preserved email with two named PDF attachments.A dated general regime distinction within the supplied record; not proof of receipt or agreement.
2023Measurement quantization, published theoretical paper.Public theoretical context cited by the later review; inspect its original equations for priority claims.
September 8, 2025Zhang and colleagues’ review.Independent review citation; not an experimental adoption of MQ.
April 16, 2026NIST/BIPM redetermination publication.Publication date, not the start date of the apparatus or all data collection.
Later MQ comparisonSpecific free-deflection / servo realization assignment.Retrospective apparatus interpretation, distinct from the general 2021 statement.
November 5, 2026This brief.Current arithmetic and editorial preparation date.
Figure 4 · Open the supplied 2021 email facsimileSupplied email screenshot dated September 26, 2021, describing electromagnetic versus macroscopic approaches to gravitational measurement and showing calculated CODATA-related values.
Figure 4. Unaltered author-supplied screenshot. It is a documentary copy, not an authenticated mail-server export. Its attachment contents and delivery history are not established by the image. Historical terminology in the message is retained. [14]

“Most simply, you are selecting experiments that use either an electromagnetic (quantum) or macroscopic approach to the measures of G and ħ.”

This selected transcription makes the message’s general distinction accessible without opening an attachment. The screenshot’s calculation table includes expressions using both ℏ and G as inputs; it should not be described as proving that all those tabulated values were derived independently of G. The correspondence also does not demonstrate that the later exact mode assignment was preregistered, that a recipient replied, or that NIST endorsed or acted on it. Source versions and the original export can be requested through the Institute’s media contact. [14]

The proposed experiment: a controlled comparison in one shared apparatus

The Institute proposes a contactless beam experiment that keeps the apparatus and persistent magnetic support circuit shared while alternating calibration, free-mode and electrostatic-mode states. The current public top graphic identifies Project 2.39, October 30, 2026, retaining the geometry/method snapshot identified as 2.37. Its lower page text also contains older baseline material. The specifications below come from the dated current graphic; earlier design numbers are not combined with them. [13]

Figure 5 uses the Institute’s current concept illustration; Figure 6 redraws the functional arrangement and Table 10 collects the declared dimensions and schedule. Table 11 preserves the current 14-entry comparison ledger.

Current Informativity Institute concept illustration of a horizontal truss beam inside a vacuum chamber with optical and magnetic-support equipment.
Figure 5. Current illustration supplied by the Institute for this brief. It depicts the proposed apparatus; it is not a photograph of an operational instrument or evidence of a built, qualified facility. The engineering diagram below provides the specified functional scale. [13]
proposed experiment schematicConceptual one-metre truss with two nominal half-kilogram end masses, a central magnetic support and optical spots. State boxes identify calibration, free mode and electrostatic mode.Proposed contactless beam: what changes, what stays sharedPersistent magnetic support / central Nb shell0.500 kg0.500 kg90 mm ODOptical spotOptical spot1 m SiC truss • two-spot 1550 nm optical readoutC · calibrationClosed support circuitF0 · free modeRF off during scienceE · electrostatic modeRF off during science
Figure 6. Native HTML-embedded SVG explanatory redraw of the current design snapshot. Optical spots sense body rotation and local deformation; neither an angular offset nor an optical phase offset by itself establishes a gravitational-torque difference. Diagrammatic component positions are illustrative, not a fabrication drawing. [13]
Table 10: Current proposed apparatus and measurement schedule
Design itemDeclared design value / operation
Beam and end masses1 m SiC truss; nominal 0.500 kg test masses at each end; truss depth 160 mm and width 60 mm.
Central shellContinuous niobium shell: 90 mm outside diameter, 2.5 mm wall thickness.
Represented inventory3.478393 kg, including stated proxy masses and allowances; not a weighed completed assembly.
Magnetic-support model150 mm coil radius, centers ±110 mm; calculated operating current 40.0604 A.
Optical readoutTwo end spots at 1550 nm; joint estimation of body rotation, local strain and optical phase.
State sequenceC / F0 / E / E / F0 / C for source +; repeat for source −. Each dwell 600 s; 12 dwells per 7200 s block.
Science conditionsRF off during science; no rotor wires; common persistent support circuit remains closed.
Calendar plan504 blocks = 42 block-days: 28 F0/E science days + 14 in-block calibration days. Add 12 engineering + 6 overhead days = 60 calendar days.

The proposed reference source-reversal torque is 260.791678 nN m. Applying the design’s frozen, rounded 34.93-ppm contrast conditionally gives 9.1094533 pN m. This engineering normalization is not an independently derived apparatus response to MQ. Using the current unrounded 34.928385-ppm target instead gives approximately 9.1090323 pN m; the ledger below retains the design’s frozen denominator so its ppm values remain reproducible. [13]

τgap, ref=τref×34.93×10−6(8h)

The current design ledger consolidates overlapping terms into 14 comparison entries. Its largest entry combines optical, mechanical and thermal behavior; the next is source/self-gravity modeling. Their stated root-sum-square total is summarized below. These are unqualified comparison estimates that may overestimate or underestimate real uncertainty, not achieved instrument performance. [13]

Table 11: Proposed comparison ledger, retained current design entries
EntryTorque estimate (aN m)ppm of conditional gap
Joint optical / mechanical / thermal46.4033365.093976
Photon effects1.6811630.184551
RF effects0.2161330.023726
Matched pose0.5773500.063379
Timing0.5773500.063379
Acceleration parasitics1.7724650.194574
Stiffness0.2886750.031690
Waveform0.2886750.031690
Magnetic history0.2886750.031690
Other thermal0.2886750.031690
Charge0.2309400.025352
Inertia0.1154700.012676
Source / self-gravity13.1483951.443379
Analysis0.1154700.012676
Root-sum-square total48.3036705.302587

a Here 1 aN m = 10⁻¹⁸ N m, 1 pN m = 10⁻¹² N m, and “ppm of gap” uses the approximately 9.10945-pN m conditional gap as denominator. These ppm values do not use the full source torque or the gravitational constant as denominator. Displayed rounded entries need not reproduce every last digit of the retained design total.

The two leading entries account for approximately 92.29% and 7.41% of the retained variance. A 5-ppm-of-gap benchmark corresponds to about 45.55 aN m; the listed 48.30-aN m total is 5.30 ppm of gap. Neither number is an experimental uncertainty already demonstrated. Establishing that budget requires measurements of drift, alignment, thermal response, source reversal, optical phase, support history and covariance between retained terms. Root-sum-square addition is justified only to the extent that the retained grouping removes double counting and residual cross-correlations are negligible or included. [13]

Table 12 gives a different precision benchmark: the standard uncertainty of the measured mode contrast, in ppm relative to the servo coupling. For an unbiased Gaussian contrast with the full systematic budget included, nominal separation from zero is the target divided by that standard uncertainty. These thresholds do not use “ppm of gap,” and they do not establish that the proposed apparatus can reach them. [3] [9]

Table 12: Prospective contrast-precision benchmarks, distinct from the engineering ledger
Nominal separation of MQ target from zeroRequired contrast standard uncertainty (ppm of servo value)Calculation
3 standard uncertainties11.642834.928385 / 3
5 standard uncertainties6.985734.928385 / 5

a A sensitivity calculation under the stated model, not a forecast of an achieved significance, a posterior probability or a substitute for conventional-offset testing.

What would make this a discriminating MQ test?

Before examining the relevant contrast, the experiment would need a fixed mode-to-realization map, signed target, torque estimator, material/configuration choices, inclusion rules and correlated uncertainty model. Calibration must separate real torque from optical-path change, local elastic strain and feedback effects. A universal extra rescaling of every apparatus length is not an established conversion model and can give the wrong sign. The required prediction is for the actual instrument estimator, with existing laboratory electrical calibrations counted once. [3] [6] [13]

An independently reviewed implementation could then compare a fixed MQ contrast with zero and with explicit conventional-offset models, repeat source reversals and configuration changes, and publish raw time series with calibration and covariance records. The proposed experiment has not yet supplied such a result. It provides a prospective route to a stronger test than a retrospective comparison of historical means. [13]

Source trail and useful follow-up reading

For the experimental story, start with NIST’s abstract, motivation, uncertainty tables and consensus construction; then read the review’s Section 5.3 rather than relying on the citation alone. For the MQ claim, follow the count relation, denominator convention and apparatus assignment separately. The existing mode-gap evidence brief provides the input and covariance tables; the gravity derivation page links the current normalization; and the planned experiment page carries the evolving design snapshot. [1] [2] [3] [6] [13]

The publication index lists the eight published MQ papers and their journal links. The historical-comparison page explains the Institute’s contribution catalog and scoring method. Those catalog scores are the Institute’s authored assessment, not an independently calibrated measure of theory validity or a substitute for the experimental comparisons here. The correspondence brief expands the documentary timeline. [14] [15] [16]

For an interview, the unresolved technical questions are concrete: Which physical estimator makes the mode assignment valid? Can the original historical grouping file be released? How robust is the contrast to configuration-specific unknown offsets? Which experiment parameters and analysis rules will be fixed prospectively? Answers to those questions would materially strengthen a story without changing the published measurements.

Interviews and technical source requests

Hoyt Hudson · Media inquiries · HoytHudson@informativity.org
Informativity Institute · Technical and documentary requests · info@informativity.org
Institute media contact page

Research sources and further reading

  1. S. Schlamminger and colleagues, Redetermination of the gravitational constant with the BIPM torsion balance at NIST, Metrologia 63, 025012 (2026). DOI: 10.1088/1681-7575/ae570f. See motivation/background and Tables 16–18; published April 16, 2026. Read the NIST-hosted paper →
  2. Y.-J. Zhang and colleagues, Progress on measurement of gravitational constant G, Measurement Science and Technology 36, 092003 (2025). DOI: 10.1088/1361-6501/adfd00. Published September 8, 2025; Section 5.3 and reference 154 discuss Geiger’s approach. Journal record →
  3. Informativity Institute, Gravitational mode-gap evidence and its limits. Current technical reconstruction: four input pairs, covariance, likelihood comparisons, denominator convention and retrospective apparatus assignment. Read the technical reanalysis →
  4. T. J. Quinn and colleagues, A new determination of G using two methods, Physical Review Letters 87, 111101 (2001). DOI: 10.1103/PhysRevLett.87.111101. Primary BIPM Mark I record. Author-institution publication record →
  5. T. Quinn, C. Speake, H. Parks and R. Davis, The BIPM measurements of the Newtonian constant of gravitation, G, Philosophical Transactions of the Royal Society A 372, 20140032 (2014). DOI: 10.1098/rsta.2014.0032. Corrected Mark II context. Author-institution publication record →
  6. Informativity Institute, Gravitational Constant G: MQ Derivation & Experimental Test. Current finite-count/upper-count relation, normalization and numerical edition. Read the gravity derivation →
  7. Informativity Institute, Fine Structure Demarcation. Current technical explanation of the calibrated separation count and residual; read alongside the linked gravitational-constant preprint. Read the demarcation treatment →
  8. CODATA recommended values of the fundamental physical constants: 2022, Journal of Physical and Chemical Reference Data 54, 033105 (2025). DOI: 10.1063/5.0279860. Input values, covariance and adjustment context. Read the NIST-hosted CODATA report →
  9. Jody A. Geiger, The Rules Beneath Reality, author-supplied manuscript, Chapter 7, reviewed for the historical midpoint calculations and the frozen statistical summary. Unpublished source version supplied for preparation of this brief; request the relevant excerpt and underlying population dataset from the Institute. Request the source excerpt →
  10. JCGM 100:2008, Evaluation of measurement data—Guide to the expression of uncertainty in measurement. First-order propagation with covariance. Read the GUM →
  11. H. Akaike, A new look at the statistical model identification, IEEE Transactions on Automatic Control 19, 716–723 (1974). DOI: 10.1109/TAC.1974.1100705. AIC source →
  12. G. Schwarz, Estimating the dimension of a model, Annals of Statistics 6, 461–464 (1978). DOI: 10.1214/aos/1176344136. BIC source →
  13. Informativity Institute, planned measurement-mode experiment. Current top graphic: Project 2.39, dated October 30, 2026; retained geometry/method snapshot 2.37. Historical midpoint tables and current proposal ledger. Design figures are estimates, not demonstrated performance. Read the experimental proposal →
  14. Author-supplied email screenshot, embedded sent date September 26, 2021, 3:11 p.m.; reproduced unchanged in Figure 4. The public correspondence brief explains the distinction between this general statement and a later apparatus-specific assignment. Original export and attachments may be requested. Read the documentary context →
  15. Informativity Institute, publication index. Eight published MQ papers with journal links; distinguish published research from current website preprints and retrospective briefs. Browse published papers →
  16. Informativity Institute, historical discovery comparison. Institute-authored inventory and scoring methodology; not an external validation scale. Read the comparison methodology →
  17. Informativity Institute, Gravitational constant from first principles, current website preprint and derivation context. Read the current derivation preprint →
  18. J. A. Geiger, Measurement quantization, International Journal of Geometric Methods in Modern Physics 20, 2350069 (2023). DOI: 10.1142/S021988782350069X. The MQ paper cited as reference 154 in the 2025 review. Current website editions and apparatus interpretations must be distinguished from this published source. Published MQ paper →
  19. J. A. Geiger, author clarification on logical foundations, realization and system selection, November 2, 2026. Supplied authorial source, reviewed in the current source compilation dated November 3, 2026. It distinguishes law-form derivation from universe/state/unit selection and specifies the four input roles; it is not an independent validation of those derivations. Request the shareable source from the Institute. Request the foundational clarification →

Preparation scope: source PDFs, supplied manuscript and correspondence image, current Institute pages and the dated proposal snapshot were reviewed. Rounded-input calculations were independently regenerated for this brief. The historical population grouping and the reported extra-heterogeneity comparison were not independently reconstructed because their complete inputs were unavailable. Figure 4 and the current experiment illustration reproduce supplied images; other graphics are explanatory redraws.

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