13. Đảo ngược

Nguyên tắc con

1. Do the opposite of the action the problem calls for
2. Fix the part that used to move and move the part that used to be fixed
3. Turn the object upside down

Ví dụ

• A treadmill where the belt moves instead of the person
• A lathe that spins the part instead of the tool
• A dish rack that dries plates upside down

Ứng dụng theo lĩnh vực

• software: An app that keeps asking the server for news floods it with useless requests. Turning it round, the server tells the app only when there is news.
• mechanical: Walking round a large structure with a welding torch means awkward positions and uneven welds. Fixing the torch and turning the structure on a rotating fixture keeps the weld in the easy position.
• materials: Pouring molten metal in from the top of a mold drags in bubbles and dross. Filling the mold from the bottom upward lets the dross float to the top.
• everyday: Sauce settles at the bottom of the bottle and needs shaking out. A bottle designed to stand on its cap keeps the contents at the opening.