Why do I feel like the only things I understand about Chapter 7 are the Dimensions dancers and the rock climber? I don't feel very comfortable with the term configuration space, except for in the lower back example. The pendulum problem is an interesting one. I do understand that a long swinging pendulum, propelled by gravity, traces a circle with it's swing maxima. See this link for information from the British Science Museum on the Foucault Pendulum. Therefore, I think I understand the beauty of graphing the two circles from two pendulums on the hyperpace torus. I'm not sure I understand how, if the purple torus frequency ratio is reversed, that then the surface of the blue torus can be projected onto the purple one. It looks like that is what is happening to me, and I've read the explanation for the diagram many times. I suppose I understand that there is a correspondence and a reversal of ratios, but I can't quite visualize that surface projection happening.
The dimensionality of stage lighting is something that I can relate to. I know that the overlapping light is significant because of both intensity and color. Video projectors also mix colors of light, like the one in our classroom. How do they get such specific images with such huge circles of light? I once saw a play produced where the lighting director used shaped cutouts on the surface of the light. They created a strange effect, almost like a hallucination or a mirage. The main character was walking through a forest, and the lights shone down shadows and trees all around her. I've never seen it used since, but the effect was unforgettable.
For a mental excercise, try to imagine yourself flying high above the earth. How would you see things differently? Now try to imagine yourself as Dennis Quaid in the movie "Inner Space". How would you relate to your body differently from the inside out, instead of as a surface? Lastly, move across a room slowly, as if walking only on a straight line. How are your normal movements restricted? Can you imagine a four space creature seeing us as pathetically restricted beings at all times?