Phase 72 · causal cone · no hidden shortcut
Faster than our model is easy. Faster than our machine is the wall.
Every previous gate asked whether the trip could get cheaper, sparser or more local. This one asks the only question that could ever matter physically: did information arrive at B earlier than the fastest measured path through this apparatus — wires, clock trees, RF leakage, shared supplies, instruments and software channels — could possibly have carried it? We freeze the calibration protocol, the pre-registered quantity, and the controls now, before any hardware exists. Physical evidence remains NONE.
Phase 72 · causal cone · no hidden shortcut
This is now the decisive wall.
Before any doorway run, we must measure how fast the machine itself can carry a secret — through every wire, clock, supply rail, radio leak and software channel. A doorway claim is only meaningful against that measured envelope, never against a theoretical one.
Every earlier wall in this program was about efficiency: can the trip get cheaper, sparser, more local. This wall is about causality: whether anything arrived earlier than the apparatus itself can carry it. Passing the three-ruler test without passing the causal cone means we built a good router. That is the honest default expectation.
Synchronization is not communication
Oscillator phase alignment, synchronization, entrainment, or a pre-existing correlated state does NOT by itself demonstrate information transmission. Two clocks that were set together will agree forever without either one sending anything. The payload must be NEWLY GENERATED after the launch trigger and DECODABLE AT B ABOVE CHANCE before the calibrated causal arrival time. Anything less is a correlation we prepared ourselves.
Established precedent · borrowed concept, not a borrowed bound
Locally coupled systems have measurable speed limits
For wide classes of quantum spin systems with local interactions, correlations outside a linear 'light cone' are exponentially suppressed. Locality of the Hamiltonian implies an emergent maximum speed of information propagation, even though the theory itself is non-relativistic. (Lieb & Robinson 1972; Hastings-Koma and subsequent refinements.)
Transfer note — This is a theorem about local quantum lattice Hamiltonians. It is NOT a statement about our coupled-oscillator bench and we do not claim it constrains our apparatus.
In classical lattices such as Fermi-Pasta-Ulam-Tsingou chains and coupled-map lattices, a localized perturbation spreads with a well-defined front velocity; the perturbation front is effectively linear in time with exponential suppression ahead of it.
Transfer note — Classical analogue of the same locality intuition. Front speeds are model- and coupling-specific and must be measured, never assumed.
Analyses of memristive networks and other locally coupled dissipative circuits report cone-like bounds on how quickly a local change influences distant elements, showing the intuition is not exclusive to Hamiltonian systems.
Transfer note — Model-dependent and under active discussion. We cite it only as precedent that a locality envelope is a measurable property of a circuit, not as a bound on our bench.
None of these results are being applied to our apparatus. They establish only the CONCEPT we are borrowing: that a locally coupled system has a finite, measurable envelope for how fast influence travels. Our envelope must be measured on our own hardware, with our own cabling, clocks and supplies, before any doorway run.
The empirical causal cone
Everything inside the measured cone is ordinary
Causal-cone calibration · before any doorway run
Topology, firmware image and hash, cabling harness, clock distribution and power distribution are all frozen and photographed. Any change after this point restarts calibration.
The doorway/addressing layer is removed from the running image, not merely switched off by a flag. The machine is calibrated as a plain physical network.
After every other system is armed and recording, a hardware-timestamped, unpredictable bit or pulse is injected at A. The symbol is generated at launch, never before.
For each node, record the earliest time at which its state departs from its null distribution by the pre-registered detection criterion. Distance is graph distance AND physical distance.
Many repetitions over multiple injection amplitudes yield v_empirical — the earliest-response envelope — together with its uncertainty. The envelope is the fastest observed route, not the average one.
Controller links, RF paths, clock lines, debug interfaces, ground returns and shared supplies are disconnected or isolated one at a time where physically possible, and every possible signal path is explicitly inventoried — including the ones we expect to be irrelevant.
The causal graph includes wires, FPGA links, clock trees, RF leakage, shared power supplies, measurement instruments and software channels — NOT just the logical graph edges of the model. Anything that can carry a bit is an edge.
The bound used in every subsequent comparison is the FASTEST empirically measured channel. No doorway claim may be scored against a slower theoretical baseline when a faster empirical route exists.
Pre-registered quantity
- Δt > combined timing uncertainty (calibration envelope uncertainty ⊕ instrument jitter ⊕ clock-transfer uncertainty).
- Replication after hidden-channel audits, on independently rebuilt apparatus where possible.
- The source symbol is unpredictable and generated only at launch, so no precomputation or cached table can help.
- Information-bearing transfer: mutual information between source symbol and destination record, or decoding accuracy, must exceed chance by the pre-registered margin. Correlated oscillation alone is not transfer.
Mandatory controls
| ID | Control | Why it exists |
|---|---|---|
| K1 | Shuffled / random payload generated only after the launch trigger | Removes any possibility that the payload was available to the apparatus in advance. |
| K2 | Source physically disconnected control | With A physically removed, any apparent signal at B is an artefact. Must return chance-level decoding. |
| K3 | Destination blind detector analysis | The analyst scoring B does not know the source symbol until scores are committed. |
| K4 | Cable-length and controller-latency calibration | Every measured time is corrected by independently measured propagation and processing delays. |
| K5 | Faraday / RF isolation comparison where feasible | Distinguishes conducted paths from radiated leakage as the earliest channel. |
| K6 | Independent clocks / timebase cross-check | A second, independently disciplined timebase must reproduce the timing claim. One clock is no clock. |
| K7 | Swap source and destination | Direction-specific artefacts (asymmetric wiring, instrument placement) reveal themselves under the swap. |
| K8 | Unseen topology loaded after the firmware hash freeze | A hidden lookup table or tuned route cannot survive a topology it has never seen. |
| K9 | Positive control with an intentionally hidden shortcut | We deliberately install a covert fast path and verify the audit finds it. If the audit cannot catch our own planted shortcut, the audit fails, not the apparatus. |
What would count · decision tree
Doorway is faster than the logical C0 route, but NOT faster than the fastest calibrated physical channel.
Interesting engineering. The machine exploited connectivity that the logical model did not represent. It says nothing about physics — and this is the outcome we consider most likely.
Doorway arrival matches the causal envelope within combined uncertainty.
The doorway is riding the ordinary fastest path. Recorded, published, and the phase closes.
Doorway carries unpredictable information earlier than EVERY calibrated physical channel, survives the shortcut audits, independent timing, and replication.
Candidate only. This label means 'we cannot currently explain the timing on this apparatus'. It requires independent replication by people who do not want us to be right before any extraordinary claim is made, and it still licenses NO statement about spacetime.
In plain language
First we measure the fastest way a secret message can possibly travel through every wire and hidden path in the machine. Then we make up a secret only at the last moment. If the other side knows the secret before any measured path could have carried it, that is the test that would make us look much deeper. If not, we learned the doorway is using an ordinary shortcut.