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 browser extension that stops AI inventing numbers — by checking them against physics, not against the internet.
Nothing is stored. Nothing is sent. It runs in your browser, and it takes a minute to install.
Roughly a third of what the best AI returns cannot be built. Not suboptimal — impossible, and nothing in the reply says so. That figure is ConstraintBench, February 2026, across six frontier models: the best of them reached 65% feasibility.
START HERE
It runs inside ChatGPT, Claude, Gemini, Mistral and Meta AI and underlines the numbers nothing has checked. No account, and the conversation never leaves your browser.
Install it — one click from the Chrome Web Store
Free, on the Chrome Web Store.
A model answers as it always does. One number gets an underline. Click it, and you get the law rather than another opinion.
A MODEL’S ANSWER
In steady wind the rotor captures about 65% of the kinetic energy passing through it, and the newer blade designs do better still.
65% is above the 59.3% limit. No turbine can take more than that from the air passing its rotor — the air has to keep moving to get out of the way.
Betz 1919. Checked in your browser.
Most of the reply is untouched, including the numbers inside code blocks. Somebody who does not click sees an underline and nothing else.
The extension carries twenty-eight laws. Each is also a page you can open and use on its own, with your own numbers — which is where to look if you want the answer rather than the warning.
A checker needs an answer to check. Some of these start earlier, when you do not yet know what to ask.
Describe what you measured and what you want to know, in your own words, and it will point you at the right one — or say plainly that there isn't one here.
It routes. It does not answer — every number on this site comes from a tool that shows its working.
Or go straight to one: basketball · which explanation survives · the seven bounds · speed climbing · light time · a stream gauge, read twice · where shallow water ends · how close an engine is to its limit · the same checks, inside whichever AI you use (tool)
Energy integrity is finished enough to ship, and it is held back. The reason is written down in full →
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. How to check each one →
Four-dimensional gap decomposition. A closed physical law, run backwards: measure one side and the other falls out. The gap between the measurement and the law splits into four — the machine, the formula, the object, and which definition you chose. And when the quantity has no single definition, the gate closes and nothing is returned.