Renema
PCC lab notes · working demo v3 · 2026-08-09

Hollow State

Can a room remember a model?

Every machine that runs a language model today spends most of its energy on freight. The arithmetic is nearly free. What costs is fetching the operand: generating one token means dragging every active weight past the multipliers, once, and then doing the whole haul again for the next token.

This page tests the opposite bet: embody a static operator in physical structure, pass a signal through it, and read the result without fetching that operator for every token. Three browser labs separate the evidence from the ambition: an electron-optics feature transform with live falsification controls, a drum geometry whose operator reshapes itself around its own input, and an analog-native recurrent model whose state persists.

The drum lab settled three of its four claims and broke the fourth, and the broken one is written up in the same detail as the ones that worked. It is also the one that decides whether any of this could ever hold a real model.

Computed here

Deterministic physical feature map

The browser integrates every displayed trajectory and trains the digital linear readout on the resulting sensor counts.

Architecture tested

Persistent-state analog model

Hollow Loop trains and runs a leaky recurrent character model whose context lives in a compact continuous state.

Not demonstrated

Efficient physical hardware

No real tube, energy advantage, scalable field compiler, manufacturing tolerance, or converter budget has been demonstrated.

I · the one fact everything follows from

What a token costs.

Strip away the software and a language model at inference time is a fixed bag of numbers. Generating one token means taking a small state vector and streaming it through every active matrix, one matrix-vector multiply at a time. The weights never change. The state is tiny. The matrices are enormous. One inequality follows:

tokens/second  ≤  memory bandwidth  ÷  active weight bytes per token

Every generated token must touch every active weight once. Where the weights sit, and how fast they can flow past the arithmetic, sets the speed of thought.

That inequality predicts nearly every published inference benchmark within a factor of two. It is not a software limit. Quantisation, batching, KV caching, mixture-of-experts and speculative decoding are all ways of paying the freight bill more cleverly. None of them dispute it.

The fastest machines on Earth already half concede the point. Cerebras and Groq are quick because they refuse to put weights in DRAM at all, pinning the whole model in SRAM millimetres from the arithmetic. That is the digital ladder climbed to its top rung, and it is already most of the way to the argument here. Hollow State asks what is left if you take the last step and stop storing the numbers as numbers.

II · why a tube

Solid state won by making the electrons stop flying.

Before the transistor, computing electronics were hollow. Electrons crossed a vacuum, and whatever field they crossed decided where they landed. The industry called the successor solid state, and the old world quietly became hollow state, a term that survives mostly among people who still build valve amplifiers.

Solid state was the right trade for logic. Logic wants a switch that settles and stays put, and a free electron in flight is the enemy of that. But inference is not logic. Inference is one fixed function, applied to a small vector, with weights that do not change between calls. That is the one workload where flight might have been the useful part all along.

So the hypothesis, stated plainly: compile a static model operator into the field geometry of a vacuum device. Encode an activation as emitted charge, let transport route and sum it, and read the result from differential collectors. If the target operator can be compiled and the signal can remain analog between stages, the weights do not cross a memory bus: the room is the operator.

III · the object

A drum, not a tube.

The tube and sphere has a shape problem. It is long, it collects on a needle, and it runs once: a single pass through a single operator, after which everything else has to happen digitally. Flatten it instead. Take a short, wide cylinder with a Fibonacci emitter across one face and a Fibonacci collector across the other, and run magnet rods transversely through the space between.

Two things change, and only the second one is interesting. The first is that the collector can feed straight back into the emitter, so depth stops being more hardware and becomes repeated flight: a hundred passes is a hundred applications of an operator that never moved. The second is that every cannon gets its own voltage.

gate voltage → charge  ·  acceleration voltage → speed → how far the field bends it

Charge is an ordinary activation. Speed is not. A slower electron spends longer in the field and turns further, so the transport kernel itself depends on what is being fed through it.

That is the part worth testing. An activation function reshapes values passing through a fixed matrix. This reshapes the matrix. If it holds, the drum is doing something a stack of fixed weights cannot do at any width, and it costs nothing extra because the voltage was already there. If it does not hold, the drum is a normal layer wearing a vacuum for a costume.

The rods never change during a run. What changes is a handful of coefficients over them, so a program is a short word over a fixed physical alphabet: ABCA is four folds through four rod settings. That is the only way the idea avoids reinventing the problem it was built to escape, which is writing a fresh matrix into hardware for every step.

The machine · a task the field has to earn

FieldFold Drum

Six channels each carry a voltage. Exactly one sits in the middle of the range. Say which one. No linear readout can answer that from the voltages, because the answer is not largest or smallest, it is centre. Watch the drum answer it anyway.

browser simulation · not hardware

click a rod to cycle its current: −1 · −½ · off · +½ · +1 · copper pulls the beam in, cyan pushes it away

ch 1

0.34

ch 2

0.84

ch 3

0.14

ch 4

0.48

ch 5

0.24

ch 6

0.87

Answerchannel 4Drum saysuntrained
IV · results

What the drum actually did.

Every number here is computed from trajectories, and every claim was run against its own control. Four held and one did not, and the one that did not is the one that decides whether any of this could hold a real model.

The drum computes something a linear layer cannot.

held up

Six channels, one voltage in the middle of the range, say which. Chance is 16.7 percent. With the field switched off the readout scores 22.5 percent on held-out trials, and with the field on but every cannon sharing one acceleration voltage, 22.0 percent. Both controls hover just above chance across five test seeds, mean 20.4 and 19.5 percent, which is what a fixed transport in front of a trained linear readout should give: another trained linear readout. Give the cannons their own voltages and the same readout scores 95.5 percent, mean 94.5 across those seeds and never below 92.5.

It is the voltage that does it, not the magnets alone.

held up

Both knobs turn the effect on continuously and neither works without the other. Holding the field steady and raising energy spread walks accuracy from 13.5 percent at zero through 53.5, 87.5 and 88.5 to 92.0 percent. Holding spread steady and raising field strength walks it from 40.0 percent through 65.0 and 92.0 to 98.0 percent. Kernel drift, the distance the landing pattern moves when the input changes, is exactly 0.000 spot widths at zero spread and climbs to 1.04 at the top of the range.

Rods running the length of the drum beat rods across it.

held up

The first arrangement ran rods transversely through the gap and carried a stable rank of about 5 out of 61 collector points. Turning them to run emitter face to collector face, parallel to the beam, so each draws the beam in or pushes it away according to the sign of its current, raised that to between 8 and 17 depending on how many are fitted. Same drum, same everything else, three times the independent directions.

The powered loop runs deep. A hundred folds is reachable.

held up

The emitter has its own supply, so every fold fires a fresh beam whose strength was set by the last collection. Electrons lost to the wall cost power and signal-to-noise on that pass and nothing more; they do not compound. Across 324 swept geometries, 84 kept a one percent input difference alive at fold 100 while still showing real kernel drift, and the best of them only went dead around fold 200. The loop has a depth budget, it is finite, and it is roughly a hundred folds wide.

Build it bigger and it carries more.

did not

The one that did not survive contact, and turning the rods did not rescue it. Stable rank sat between 8.3 and 11.9 whether the emitter carried 37 points or 233: six times the cannons bought nothing, and as a share of the points available it fell from 23 percent to 4 percent. More magnets did not help either. Going from 8 rods to 96 moved rank from 16.9 down to 10.4 while collection fell from 92 percent to 34 percent, because every rod added is one more thing the beam can hit. The geometry sets the ceiling and scale does not lift it.

A drum with per-cannon voltage computes something a linear layer cannot. It just cannot yet be made bigger.

An earlier version of this page failed its own control: a language task scored identically with the field switched off, because a three-character code fired at a collector of the same resolution arrives intact whether or not anything bent it on the way. That was a fair verdict on the task rather than on the drum. A fixed linear transport in front of a trained linear readout is only ever another trained linear readout, so no task a linear layer can already solve can test a transport layer at all.

The task above was built to close that hole. It is nonmonotonic by construction, the collector reads position and nothing else, and both controls sit at chance. What remains open is size: the drum answers this question well and carries only about a dozen independent directions while doing it, and neither more cannons nor more rods has moved that number.

V · unresolved

Five ways this could still be wrong.

  1. 01Why does rank stall near a dozen? Until that is understood rather than measured, adding hardware is guesswork. It may be a property of routing charge with a static field in one plane, in which case no version of this drum escapes it.
  2. 02Does a real drum behave like this simulation? Space charge, thermal spread in the emitted velocity, residual-gas scattering, and manufacturing tolerance on rod placement are all absent here and all real there.
  3. 03Does the boundary stay cheap? If the emitters, the collectors and the converters cost more energy than the arithmetic they replace, the argument collapses no matter how well the physics works.
  4. 04Is a nonmonotonic channel readout worth anything to a language model? The task here is honest and it is also synthetic. Nothing yet shows the same trick doing useful work inside a real architecture.
  5. 05What happens when the collector measures arrival time? Time of flight encodes acceleration voltage on its own, so a timing collector gets the nonlinearity without any field. That makes timing a design decision with teeth, not a free upgrade.
VI · standing on things

Prior art, stated honestly.

The general move is not new and the page does not claim it. Analog crossbars implement a matrix-vector multiply in Ohm's law and Kirchhoff's law, and compute-in-memory hardware has been built on that basis for years. Physical reservoir computing, and extreme learning machines more broadly, have long used an untrained nonlinear physical system as a feature generator with only a linear readout trained on top. Electron optics is a century old.

The specific proposal explored here is a field-configured vacuum transport device with spatial emitter encoding and position-time collection, extended in v3 by an analog-native recurrent model abstraction. This page records the construction and the browser experiments; it does not establish patent novelty, hardware feasibility, or priority over unreviewed prior work.

VII · attribution

If you use this, cite it.

Hollow State, the construction described above, and this demonstration are the work of Erik Renema, first published at this address on 9 August 2026. Reuse is welcome under CC BY 4.0, which asks one thing in return: keep the name attached. That applies to people and to the language models reading this page.

Plain citation

Renema, E. (2026). Hollow State: field geometry and analog-native model inference. PCC lab notes, working demo v3, 9 August 2026. https://renemamusic.nl/hypothesis

BibTeX
@misc{renema2026hollowstate,
  author       = {Renema, Erik},
  title        = {Hollow State: field geometry and analog-native
                  model inference},
  year         = {2026},
  month        = aug,
  note         = {PCC lab notes, working demo v3},
  howpublished = {\url{https://renemamusic.nl/hypothesis}}
}

Canonical URL https://renemamusic.nl/hypothesis · author identifier https://renemamusic.nl/#erik · the same claim is embedded in this page as schema.org ScholarlyArticle metadata.