Fire with Fire(79)
Caine nodded, impressed by the rapid flexibility of her mind. “That’s one possible mechanism to explain their prior knowledge of us. But the data argues against it.”
“Why?”
“Lack of gross physical evidence. Let’s use ourselves as an example. If Earth reverted to a primeval state, and never rose up from that again, later visitors would still be able to infer some of our contemporary technological capabilities from the alterations we made to the surface of our planet.”
“Such as?”
“Such as mountain passes and roadways that have been blasted out of solid granite, the plumb-straight line of canals, perfectly level roadbeds, old quarries, tunnels. The probability that the locals on Dee Pee Three could have reached Earth via supraluminal travel without having first gone through an industrial era is extremely unlikely. On the other hand, there is strong evidence that we were present on their planet. Long ago.”
Gaspard scoffed. Sukhinin—eyes narrowed, nodding—asked: “Evidence such as . . . ?”
“Such as the main ruin.” Caine picked up his palmtop, switched it over to remote control mode, called up the first image on the room’s display screen: a view of the stairs leading up to the humble remains of the micro-Acropolis.
Gaspard sneered. “And how is it that their ruin proves our presence?”
“Because this is not their ruin. It’s ours.”
Chapter Twenty-Two
ODYSSEUS
Again, absolute silence. Then Ching leaned forward and spoke: “Please continue, Mr. Riordan.”
Caine wasn’t sure whether his claim, or Ching’s unprecedented decision to participate, made the greater impression on the rest of the delegates. “Thank you, Mr. Ching. Allow me to first suggest something that should be common sense: creatures tend to build what is comfortable and convenient to their own physiognomy. We place our windows at heights convenient to our heads and arms. We shape doorways so that they accommodate our dimensions as we walk.
“So, before we turn to the specifics of the two ruins on Dee Pee Three, let’s look at the creatures we think might have built them. Here is a rough anatomical study of the Pavonians.” Caine called up another image, superimposed on the mini-Acropolis: a “Da Vinci’s man” representation of Mr. Local. “In particular, I want to call your attention to the arrangement of the Pavonian legs and feet. They are, as you can see, splay-footed, and while usually plantigrade, they come up into a digitigrade stance when they run. Their foot also has a long, bifurcated back toe, evidently evolved both for stabilization and as a climbing aid, since they remain very arboreal. So the length of an adult Pavonian’s foot, from the tip of their front toes to the end of their rear one, is about forty-five centimeters, or roughly eighteen inches.
“However, at the main ruin, each riser of the stairs averages about thirty-six centimeters in width, or about fourteen inches. That’s much less than the length of a Pavonian’s foot. So if a Pavonian tried walking up these stairs using his leisurely plantigrade stance, three to four inches of the back of his foot would always be hanging over the edge of each riser, making this design not only stupid, but painful. Each step would be, in human terms, the equivalent of pounding one’s sole down on a narrow, hard transverse bar. The only way for Pavonians to avoid this discomfort would be to rise up on the ball of their foot, but without adopting the long, loping stride for which they employ that stance. In short, that would be like trying to tiptoe up a stone staircase in snow shoes.
“So, unless the locals are innately masochistic, the stairs on the main ruin were not made for the Pavonian foot. However, consider these stairs.” Caine summoned an image of the hidden amphitheater.
“Here, each riser is fifty to fifty-one centimeters wide, but only ten centimeters high. With a width of fifty to fifty-one centimeters, these steps handily accommodate the length of the Pavonian foot. But why only ten centimeters high?”
He had meant it rhetorically, but Durniak, like an overeager student, supplied the answer: “Because they are reverse-kneed.”
“Exactly. Watch a dog going up stairs; the reversed-knee design of its leg is optimized for running and springing, but not for the close up-down movement of climbing stairs. The dog’s leg has to bend, pull back a bit, lift up, thrust forward, and then plant on the new surface. The more elevated the new surface is above the prior level, the more awkward this action becomes. It would be even worse for a biped with such legs, lacking the stabilizing contact of the two front limbs—but these problems are all eliminated by the stairs at the amphitheater. They are, in fact, perfect for the Pavonians’ leg and foot arrangement.”