[Physicist]

That's right.

[PatrickHenry]

If we were flatlanders, living in a 2D plane, and a 3D rod were perpendicular to our plane, we'd see it only as a 2D circular cross-section of the rod. I see no possibility for simulating mass. If the rod were in motion, passing through our plane, I still see no illusion of mass. I'm obviously missing something. Perhaps if we could, in our 2D way, handle the circle, and test its mass, it would then reveal the effect of the motion, but we wouldn't know about that motion. We'd just think it was massive, and we wouldn't know why. Is that it?