1. Commonsense Reasoning and Science

3. Understanding variants What would happen if: There were no test tubes? The test tubes were right side up? The test tubes were slanted? The test tubes were initially full of air? One of the electrodes was outside the tube? Both electrodes were in the same tube?

4. Understanding elementary science is not just knowing formulas like 2H 2 O → 2H 2 + O 2 One has to be able to connect this to the world as perceived and manipulated at the human level. That is, to one’s commonsensical understanding of the physical world.

5. Qualitative reasoning You don’t need exact shape or physical information to see how this works: Shape of test tube Shape of beaker Voltage between electrodes Exact position of electrodes

6. You may not have this information Can’t perceive or measure Changed since perceived/measured The system is incompletely designed Reason about classes of system

7. But you do need some geometry The beaker can hold water. The test tubes are upside down with their openings in the water. The electrodes are inside the tubes The tubes are initially full of water The tubes do not have a hole on top The interiors of the tubes are separated

8. The Problem To carry out physical reasoning at the commonsense level based on qualitative information.

9. Applications Robotics + planning Vision Natural language disambiguation: “The pure elements are collected in separate tubes.” => Quantities of oxygen and hydrogen gradually accumulate, each in its own tube, and are confined to remain there.

10. Standard theories AI: Atomic actions, discrete changes, little geometry. Scientific computation: Generally requires quite precise boundary conditions. Step by step simulation.

11. My approach Characterize general laws, problem specifications, needed to support inference Particular emphasis on –Qualitative geometry –Reasoning over extended time

12. Specific domains Previous work: Cutting solid objects. Carrying objects in boxes. Current projects: Pouring liquids Carrying objects on trays bbbb