cert-machine · instruments

Nine instruments, and each one says what decides it.

This page used to open by saying that nothing here was certified. That was the wrong claim and it had stopped being true: two of these pages draw a certificate straight from the shelf the rest of the site gates, and five of them decide their headline number in exact integer or rational arithmetic. What is true is that nothing here is gated — no number on these pages has a certificate row the build checks, no page here can refuse a deploy, and none of them is covered by make test. That is a fact about ceremony, not about the mathematics, and the two are not the same thing.

So instead of one disclaimer at the door, every card below says what backs its headline number, in the same words the pages use: exact rationals, exact integers, a record from the certificate shelf, or floats. Where it is floats, the page says so beside the number rather than at the bottom.

the projects nine, so far
0123456789308,976,661 shape tests · 45,898,801,200 permutations
A symmetry, recovered from a model’s own answers. Each chord joins an item to where the permutation sends it, so a rotation reads as a fan and a reflection as rungs across an axis. Nobody asked about symmetry; it is what survived when everything else did not.
shape hunt · five studies · no model calls
what decides itexact rationalsevery survivor is recomputed in exact rationals, and the impossibility witnesses clear a floor that is proved rather than sampled

Nothing here is a perfect circle.

The elicited geometries look like they hold shapes — a pentagon here, four points on a circle there. So this looks exhaustively, at every triple and quadruple and five-subset of every set from every model, and then runs the identical search on the same numbers with the geometry shuffled out. Almost nothing survives that. What does is not a polygon — and for most of the sets the verdict is not a margin at all but a certificate in whole numbers that no such points exist.

collinear triples found0 of 54not one, in any set, better than shuffling the same distances would give
regular pentagons2 of 54and the roundest pentagon in pure noise looks exactly as convincing
symmetries that hold24 of 54under two nulls of opposite bias that no control clears — including the antipodal map on the compass, which nobody asked about
provably not distances41 of 54refuted above a floor that is proved rather than sampled, each with a four-item witness — while the nonsense controls embed exactly
read the hunt
longest baseline 7.35 Gλ
This is the whole of what was measured. 7,317 samples from 26 telescope pairs on 21 April 2018, each pair sweeping an arc as the Earth turns, each arc mirrored because a real sky makes every measurement two. Everything between the arcs was never observed — and that empty space is the reason there is a set of pictures rather than a picture.
interferometer · M87 · 227 GHz
what decides itfloatsa certificate-shaped bound with no proof on disk yet, and the page leads with that

Not the picture. The set of pictures.

The famous black-hole image is one sky chosen, by an imaging prior, from the infinitely many the data allow. This draws the set instead: 18 skies fitted under deliberately different priors, agreement rendered as ink and disagreement as texture. One slider decides how much of the phase information the picture is allowed to use — and at zero the ring dissolves, because amplitudes alone cannot see where anything is.

visibilities838released rows, one calibration pipeline, one night
stations826 baselines, 544 closure triangles
skies drawn18 + 4fitted members, plus extremes that push the data’s limits
bracket82%worst of 4 radii — a prior-free, phase-free enclosure, best 67%
open the instrument
0.0M0.6M1.3M1.9M2.5M3.2M-0.09540.5221.141.762.37 a measured deflection of 1.15reported ±568 lb — narrower than the dot drawing it load (lb) deflection 132× the reported ±, assuming only monotone
The same question, on something everyday. Twenty loads applied twice at NIST, and the whole set of calibration curves those standards allow — solid, because it is what the data forces. The published quadratic is the dotted line inside it: one member of that set, chosen by a fitting criterion rather than by the measurements.
curveset · 2 real calibrations · no model calls
what decides itclosed form, in floatsthe envelope is a min and a max of straight lines, so it is exact as a formula and evaluated as a double

The line they published, and the lines that fit.

A calibration is run forwards and used backwards, and the backwards number always comes off a fitted curve. The fit is an assumption and it is never priced. This computes what the standards allow instead — in closed form, no optimiser, no sampling — under assumptions you can dial one at a time, from monotone only to join the dots, with the parametric fit past the end of the dial.

load cell, monotone only132×the honest interval is exactly the ladder spacing — which two standards you are between, and nothing finer
and joining the dots1.0×linear interpolation lands on the reported precision: on a fine ladder the functional form buys nothing
the assay, joining the dots3.6×the opposite verdict — on a coarse ladder the four-parameter form is doing the work
the mathematicsclosed formU and L are a min and a max of straight lines, so reading backwards is a bisection and the page runs the file the tests run
turn the dial
mod 2mod 5mod 10mod 10012717PLATE In = 0 … 99 threaded across mod 2, 5, 10, 100. the heavy thread is 17.plate I of 8 · n = 0 … 99 across mod 2, 5, 10, 100
A number as a point on a product of circles. Interpretability research reports that a model stores a number as a set of residues, one angle per modulus, and adds by rotating all of them at once. Drawn here from the definition rather than recovered from activations — the honest way for this bench to hold the object.
plates · 8 figures · no interaction, no model calls
what decides itrecords from the certificate shelfplates IV, VII and VIII are drawn from certificates the rest of the site gates; the other five are rules stated and drawn

Manifolds we are handed.

Their manifolds are found — pulled out of a working model and interpreted. These are stated: a rule, its parameters, and then a drawing. Two of the eight are not illustrations at all but certificates rendered at their own resolution, which is what a proof looks like when you stop reading it and start looking at it.

a proof, tiled1,350 boxesbrightness is how little room each box had — the bright seams are where the argument nearly ran out
the tightest box4.12e-7one number, and the whole lower bound rests on it
the instrument itself838 ringseach measurement is a circle: the radius is known, the angle on it is not
the grammar, foundplate Vsolid for a bound on every sky, dashed for one sky that exists — drawn that way before it had a name
open the series
pleasant →↑ activatedhappydelightedexcitedastonishedtenseangrymiserablesadboredsleepyrelaxedcontenttwelve feelings, placed by pairwise questions alone
The circumplex, recovered twice. The ring is fixed by asking only how different each pair of feelings is. The axes — pleasant to the right, activated upward — come from a completely separate question set with no words in common, and land on the plane the pairwise table had already chosen.
affect · 6 moods × 3 models · $3.71 already spent
what decides itexact integersthe signature, the negative mass and the metric gate are decided on the integer table; the plates are float drawings of it

The geometry of feeling, and the control that catches it.

Twelve feelings, then the same twelve asked again under six moods — and twelve clock hours carried through the identical pipeline as a control that has no business moving. A mood effect that also moves the clock is not a mood effect. One model’s clock moves anyway.

two question sets, no words sharedr = 0.98, 0.98, 0.95pleasantness, agreeing between the plane the pairwise table fixed and the scalar answers it never saw
and it is the leading axis1°, 6°, 0°pleasantness lands on that plane’s own principal axis — an axis fixed before any scalar was read
but a plane it is notrank 9, 9, 10with 11%, 9%, 23% negative mass — no arrangement of points in any Euclidean space has these distances
the control movesup to 85%twelve clock hours, under a mood, in the smallest model — which is exactly what a control is for
read the moods
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,123456789101112every pair asked both ways round
Three models in one frame. A table of distances fixes nothing about rotation, reflection or overall size, so putting three of them on one axis means removing exactly those freedoms and nothing else. What is left is disagreement about shape.
answer shape · 7 subjects × 3 models · $1.65 already spent
what decides itexact integerssame instrument, same exactness — the triangle inequality and the signature are decided, the pictures are views

The shape of an answer.

Ask how different two things are, one pair at a time, and you get a table of numbers. A table of distances is a shape — or it is not one, and the difference is decidable in exact integer arithmetic. Every pair is asked both ways round, so the asymmetry is measured rather than averaged away.

the hue wheelred beside violetthe one cycle that is not a convention — a model that puts them at opposite ends has learned a list of colour words, not a colour space
where the triangle failsup to 23% of triplesbreak d(a,c) ≤ d(a,b) + d(b,c) — so no arrangement of points in any space has those distances
the nonsense controlmetricstrings that are not words come back as a clean metric in all three models, which is what a control is supposed to do
line or cycleboth, measuredeach table held against the two shapes it could have, one free scale each, fixed in closed form so the residuals compare
compare the three
redorangeyellowchartreusegreenspring gr·cyanazurebluevioletmagentarose 527 calls · $0.78
Twelve colour words, placed by a model that has never seen a colour. Every chord is one pairwise judgement, weighted by how similar the model called the pair; the solid path walks red → orange → … → rose and the dashed step is the way home. It closes. Nobody asked for a wheel.
neural geometry · 3 models · no weights
what decides itexact integersasymmetry, closure, the triangle inequality, Gromov delta and the Gram signature, all decided on integers

The shapes a model will admit to from the outside.

Goodfire finds circles and colour surfaces by opening the model and decomposing its activations, which needs the weights. This asks from outside instead — every pair, one integer, one row at a time — and then decides exactly what those answers can be. If the circle is real it should survive being asked about; a shape that lives only in the activations was never a shape the model uses.

curved directions0in the unrelated control, in all three models — while every structured set carries several. Structure shows up as the refusal to be flat.
the hue wheel1.28×the step home against the median step along the way — red really is next to rose
as bare digits5.48×a line: nine is nowhere near zero, and the control frame “floors of a building” changes nothing
as residues mod 101.46×the same ten numerals the model lays on a line as digits — renamed, they close into a ring
read the plates
,,,,,,,AAGLLMMGMM8 sets whose shape is fixed by construction
The positive control for every geometry page here. Five telescopes at one instant are points in a plane by construction, and there is no room for argument. If the instrument does not come back with effective rank 2 and nothing negative, the arithmetic is broken and every other number is worthless.
exact geometry · 8 sets · no model calls at all
what decides itexact integersand the predictions were written before the run, which is the only thing that makes "agreed" mean anything

Point it at something whose shape is already known.

Every other geometry page here asks a model for a table of dissimilarities and decides what shape the answers have. This one asks nothing. The prediction is written first, in the source, and never edited afterwards — which is the only thing that makes “agreed” mean anything.

predictions that held8 of 8written before the run, in sets.js, and not touched since
refused at the gate1a set that violates the metric gate is refused rather than scored — running the arithmetic anyway returns a plausible number from a broken input
the awkward reading, keptsignaturequantising a projection to integers guarantees the exact signature will not come back clean, so it is printed beside the rank rather than instead of it
read the controls
31 positions
One attention row, drawn where it lives. The 31 vertices are the 31 positions the head can attend to; the row is the point. It starts at dead centre — attending to everything equally — and the trail is where sharpening the temperature takes it. Solid while the claim is decided, dashed once it is only drawn.
attention geometry · one frozen row · exact
what decides itexact rationals for the claimconsecutive values differ in the fourteenth decimal, so the monotonicity is decided on BigInt fractions; the trail is dashed where it is only drawn

An attention row is a point. Nobody draws it that way.

Attention weights are nonnegative and sum to one, which makes a row a point in a simplex — and a bar chart throws that away. Focus is distance from the centre; concentration has contours; temperature is a path. One real row from a tiny GPT, in the room it actually lives in, with the one claim about it that is decided rather than drawn: sharpening must move the point toward a vertex, proved in exact rational arithmetic because consecutive values differ in the fourteenth decimal.

positions31layer 0, head 0, seed 0 — frozen once and sha-pinned
checks, exact9/9including two planted mutants that must fail to concentrate
effective positions31.00 → 29.80across the decided grid, out of 31
drawn past it1.08at β 400, essentially a vertex — and dashed, because it is not decided
open the instrument
built 2026-09-04