A physics engine, and a verification tool enforced on top of it. PhysWall inverts a closed, published, non-linear physical law at a single measurement point — and refuses when the inverse is not unique. Seven laws, one engine, and the same refusal in all of them.
A physical-logic engine that decomposes a measurement gap along four axes — the machine, the law, the object, and which definition — and runs every domain through one structure.
RF matching, PCB loss, orbital conversion, photonic scattering, stream gauges, ocean waves, basketball. Same engine, same refusal: when the measurement cannot carry a conclusion, it says so instead of answering.
Five things could explain it. Which can you rule out?
Most reasoning goes the other way — pick the likeliest and look for support. That finds evidence for whatever you picked, which is why it feels so convincing.
hypothesis what would follow what you observe flat battery lights dim or dead lights are bright starter motor silence, no crank it cranks no fuel cranks, will not fire cranks, will not fire immobiliser dash warning lit no warning blocked filter cranks, will not fire cranks, will not fire
Three ruled out by what you can see from the driver's seat. Two survive, they predict the same thing, and no amount of staring at the dashboard will separate them.
That is not a failure of the method. It is the method telling you which test to run next — and it is a different test from the one you would have run on a hunch.
Ruling out is falsifiable and asymmetric. One observation can kill a hypothesis outright; nothing can confirm one for good. So elimination makes progress that accumulates, and confirmation makes progress that evaporates the moment someone asks a harder question.
The formal name is consistency-based diagnosis, and it goes back to Reiter in 1987. We did not invent it. We made a version you can run.
When two explanations both survive, this says so and stops. It does not break the tie, because the evidence did not.
Every other tool would return the more likely one, and the ranking would come from somewhere — usually from whoever wrote the tool.
Your own case, or one of the built-in examples. Runs in your browser.
PhysWall was developed and architected by Gadi Zion.
Built on PhysWall — the same engine reads antenna bandwidth, conductor loss, bit erasure and heat limits. It answers what the measurement implies, and refuses when the measurement cannot say.⚠ Check this instead of believing it. Every number here reproduces from a source that is named, and the claims that turned out wrong are still printed next to what replaced them. The same engine runs all of these — it asks how much a measurement allows you to conclude, and refuses the same way in every field. The same engine runs all of these — it asks how much a measurement allows you to conclude, and refuses the same way in every field. How to check each one →