The calendar

When nature answers

Every live prediction. The number as frozen. What it is read against today. Who tightens that reading next, and when. What would kill it, and what would leave it standing.

Every date below is the body's own, read at its source on the day shown, with the source linked. None comes from memory. Where a body has published no date, the row says so. Dates read on 2026-10-29.

On the day, the work does one thing. A reading past the switch kills the row, and the row stays on this site, dead and dated. A reading inside leaves it standing. Nothing is adjusted after the fact.

Proton mass ratio — the series closedStep 8 · switch KS-HOLD.1

Frozen: 1836.152673445 · Read against today: 1836.152673426(32) · σ: +0.59σ

Next to tighten it

data close 31 December 2026; results “early 2027”CODATA 2026 adjustment of the fundamental constantsthe next official value of the proton–electron mass ratio, with every new measurement folded in
no published dateMolecular-ion spectroscopy (HD+ and H2+)the ratio measured directly in a molecule; the latest (H2+, 2025) is not yet as tight as the CODATA value
no published datePenning-trap mass measurements (proton and electron)the masses that feed the ratio

What kills it

Dies at 3σ once the measurement uncertainty reaches 3.4 ppt with the central value unchanged, and at 5σ at 2.1 ppt.From the frozen document, 2026-09-06-mp-me-closed. Frozen before the measurement.

What leaves it standingThe measurement tightens and its centre moves onto the frozen value, or stays within three of its new bars.

Gravitational constant G, realised — against atom interferometryStep 9 · switch KS-CCC.3

Frozen: 6.6719 × 10⁻¹¹ · Read against today: 6.67191(99) × 10⁻¹¹ (LENS 2014) · σ: +0.01σ

Next to tighten it

results “early 2027”CODATA 2026 adjustmentthe next adopted value of G; its data window closes 31 December 2026
published 16 April 2026; the group reports no next measurementNIST repeat of the BIPM torsion balance (Metrologia, 16 April 2026)the newest laboratory value of G, reported below the BIPM value and inside the world average
no published dateAtom interferometry (Florence) and other torsion experimentsindependent values of G by other methods

What kills it

Convergence upward toward 6.7206 kills the commitmentFrom the frozen document, 2026-09-04-G-KS-CCC.3. Frozen before the measurement.

What leaves it standingThe adopted value moves down, toward the frozen value, as the laboratories close their errors.

Neutron-proton mass diff, realisedStep 10 · switch KS-FLIP.1

Frozen: 2.53098857035 mₑ · Read against today: 2.53098857(74) mₑ · σ: −0.005σ

Next to tighten it

results “early 2027”CODATA 2026 adjustmentthe next official neutron and proton masses
none announcedA new measurement of the deuteron binding energythe input that limits the neutron mass today; the current one dates from 1999

What kills it

KS-FLIP.1 dies if an improved measurement of the neutron–proton mass difference departs from the expression beyond the barFrom the frozen document, 2026-09-04-neutron-KS-FLIP.1. Frozen before the measurement.

What leaves it standingA sharper measurement stays within the bar of the frozen expression.

Dark energy and dark matter — and the dark-sector clockStep 11 · switch KS-42.6

Frozen: 68.85% · Read against today: 68.89 ± 0.56% · σ: −0.07σ

Next to tighten it

“expected in 2027”DESI, the five-year surveythe shares of dark energy and matter
“mid-2027 at the earliest”Euclid, Data Release 1the same shares, from lensing and clustering
“Jul – Dec 2028”Rubin Observatory, Data Release 1the first full data release of the ten-year survey
measurements are being made; no published date for a determinationJWST and ALMA, galaxies at early timesthe ratio of dark matter to ordinary matter, inside young galaxies

What kills it

Any credible determination that Ω_DM/Ω_b was higher in the early universe than today kills it outright.From the frozen document, 2026-08-02-dark-clock-KS42.6. Frozen before the measurement.

What leaves it standingThe shares settle where they are now, and early galaxies show less dark matter, against ordinary matter, than today.

Visible matterStep 11 · switch KS-41.1

Frozen: 4.76% · Read against today: ≈ 4.885 ± 0.05% · σ: −2.46σ

Next to tighten it

“expected in 2027”DESI with the relic glowthe share of ordinary matter
no published date; the large new telescopes are named as the next stepPrimordial deuteriumthe density of ordinary matter, by a second, independent road
“December 2030”ELT, scientific first lightthe telescope the next deuterium readings need

What kills it

A determination of Ω_b/Ω_total with total uncertainty below 0.5 % whose central value lies above 4.81 % (3σ from 1/21 at that precision) fires KS-41.1.From the frozen document, 2026-08-02-visible-fraction-KS41.1. Frozen before the measurement.

What leaves it standingThe visible share settles toward one in twenty-one as the measurements and their conventions settle.

Age of the universe, one cycleStep 12 · switch KS-STRETCH.3

Frozen: 13.830 Gyr · Read against today: 13.787 ± 0.020 Gyr · σ: +2.1σ

Next to tighten it

First resultsFirst dark-energy results from the full survey “expected in 2027”DESI, the five-year surveythe expansion history, from which the age is read
DR1 “mid-2027”; cosmology results “mid-2027 at the earliest”Euclid, Data Release 1galaxy clustering and weak lensing
fully online since October 2026; first data release: no published dateSimons Observatorythe relic glow, at higher resolution

What kills it

KS-STRETCH.3 fires if the age of the universe, as the cosmological data settle it, differs from one cycle by more than one lane-time, 0.66 Gyr, in either direction.From the frozen document, 2026-09-04-age-KS-STRETCH.3. Frozen before the measurement.

What leaves it standingThe age, as the data settle it, stays within one twenty-first of the cycle.

Expansion rate H₀, the closureStep 13 · switch KS-ASM.1

Frozen: 67.45 km/s/Mpc · Read against today: 67.4 ± 0.5 (Planck) · σ: +0.1σ

Next to tighten it

“Wednesday 2 December 2026”Gaia, Data Release 4star distances that anchor the ladder
“expected in 2027”DESI, the five-year surveythe expansion rate from the large-scale map
“mid-2027 at the earliest”Euclid, Data Release 1the expansion rate from clustering and lensing
no published dateThe distance ladder (Cepheids, red giants, the 2026 community consensus)the higher number in the Hubble tension

What kills it

KS-ASM.1 fires if the expansion rate, as the data settle it, lands outside 64.4–70.8 in either directionFrom the frozen document, 2026-09-04-H0-KS-ASM.1. Frozen before the measurement.

What leaves it standingThe rate, as the data settle it, lands inside the window.

MOND acceleration a₀ (at H₀ = 67.45)Step 13 · switch KS-45

Frozen: 1.089 × 10⁻¹⁰ · Read against today: 1.20 ± 0.24 × 10⁻¹⁰ (syst.) · σ: −0.46σ

Next to tighten it

no published date for a new determinationRotation curves and lensing of galaxiesthe faint floor of extra pull at the edges of galaxies
“Wednesday 2 December 2026”Gaia, Data Release 4wide binary stars, a test of the floor in our own galaxy

What kills it

It dies if a dark-matter particle turns up in the right amount (KS-42.1), or if galaxies break the floor or its formula (KS-3, KS-45).From the wall, the420code.org/physics/.

What leaves it standingThe floor stays inside its measured bar at the closed rate.

α(0) does not vary — across place, epoch and densityStep 14 · switch KS-GLASS.3

Frozen: Δα/α = 0, structurally · Read against today: consistent with zero (Oklo, quasars, clocks) · σ: —

Next to tighten it

no published date; the first nuclear-clock bound was published 7 October 2026Optical clocks and the thorium nuclear clockany drift of the grip, here and now
first light “expected in March 2029”; scientific observations “December 2030”ELT, first lightthe telescope for the next quasar readings
first light “envisioned by 2035” (the consortium; ESO gives no date)ANDES, the ELT spectrograph for the gripthe grip, read in the light of distant quasars

What kills it

A variation of α(0) reported at five standard deviations or better, by two independent methods, standing after their systematics are reviewed.From the frozen document, 2026-09-11-alpha-no-variation. Frozen before the measurement.

What leaves it standingEvery reading stays consistent with no variation.

The two that died

Their dates are behind them. The two that died.