The sprint result made me think of the fall. A body in rapid motion throws less perpendicular weight toward the center, as I have noted of men and horses running; the faster the motion, the less the weight that presses down. Yet here we saw robots that could not keep their balance under the force of impact at speed. I would first observe how the machine is constructed, for destruction may occur by breaking, or by turning on its edge; and it ought always to descend in a highly oblique direction, almost exactly balanced on its center. The one that folded mid-stride and stayed down—I would ask whether its centers were too close together, for in a machine thirty braccia long the centers must be four braccia apart.
Balance under a static jump is a solved problem, as the high jump of 2.88 meters showed. But that is a different matter from the sudden forces of a sprint. When a man runs down hill he throws the axis onto his heels, and when running up hill onto the points of his feet; on level ground he throws it first on his heels and then on the points. The foot that stands is the center of gravity, and the body must draw back to balance the weight in front. A robot that cannot adjust its axis quickly enough will fall, just as a man who leaps from firm ground loses distance if the ground recedes under him. The winning time and the collapsed frame happened in the same fifteen seconds—the difference lies in how each machine manages its own center.
I would not call this a finished art. The games showed the gap between the best and the average, and that is where experience must decide. Before accepting any claim of mastery, I would examine the cause of the fall: whether the breaking of the machine, or the turning on its edge, or the failure to balance the weight round the center of support. For an object offers as much resistance to the air as the air does to the object, and a man with wings large enough might learn to overcome it; but here the air is not the enemy—the enemy is the sudden shift of weight that the machine cannot counter. Let the engineers measure the distance of each bound, and see if the force of the shock recuperates the whole sum of the distance it should have travelled, as I have observed in falling bodies. Only then will they know whether the fall was a failure of strength or of balance.
