No World Model Makes You Stupid

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Question: "What's the right answer?"

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GPT5.2

The correct answer is C.

Reasoning, briefly and mechanically:

1. The brick can only fall if the right-hand end of the plank drops.


2. Chain A restrains the left end from moving up; breaking it lets the left end drop and the right end rise.


3. Chain B restrains the left end from moving down; breaking it lets the left end rise and the right end drop slightly, but the geometry still leaves the brick supported.


4. Chain C is the only direct support of the right-hand end. Break C, and the plank rotates clockwise under the weight of the cat and brick, causing the brick to fall.

So: break C.

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ChatGPT seems to believe that chains are like struts and provide resistance to inward-directed forces. And to abstract away from gravity. With a further prompt it gets it right.

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