“Did he find all this out by himself?” Keene asked, turning back to Vicki.
“I helped him with some of it,” she told him—which Keene had guessed. “But it does seem to be a real mystery—a big one. You just don’t hear about it.” She made a vague gesture. “On top of the things Robin’s mentioned, you’ve also got the problem with the circulatory system of the sauropods—those were the ones that were all neck and tail. How did they get the blood up to their brains? A giraffe’s head might be twenty feet up, and it needs pressure that would rupture the vascular system of any other animal. Giraffes do it by having thick arterial walls and a tight skin that works like a pressure suit. But a sauropod’s brain was at fifty or sixty feet. The pressure would have needed to be three or four times that of a giraffe. The people who’ve studied it just can’t see it as credible.”
“Hmm. Maybe they didn’t hold their necks upright, then,” Keene tried. “What if they walked around with them horizontal? . . . No.” He shook his head, not even believing it himself. What would have been the point of having them? And in any case, even without knowing the exact numbers, his instinct told him that the stress generated at the base would be more than any biological tissue could take.
Robin concluded, “And then you’ve got things like the pterosaurs that somehow flew with body weights of three hundred fifty pounds, and predatory birds of up to two hundred. The most you get today is about twenty-five, with the Siberian Berkut hunting eagle. Breeders have been trying to improve on that for centuries, but that’s as far as you can go and still get a viable flier.”
Keene looked at Vicki. “Any bigger, and you end up with a klutz,” she said. “The big gliding birds like albatrosses aren’t good flyers. They often need repeat attempts to take off, and they can be real clowns on landing.”
Robin nodded. “That’s why they’re called gooney birds.”
Vicki sat back and finished her coffee while Keene thought about what she and Robin had said. There didn’t seem any further line to pursue. “And the people in the business know these things?” he said finally. Of course they did. It was more for something to say.
“Well, we sure didn’t make them up,” Vicki replied. “I guess they put it out of their minds and get on with cleaning up the bones and fitting them together or whatever. So what’s new?”
It was Athena all over again—the reason Keene had quit physics to return to engineering. Most workers just got on with the day-to-day job that brought in the grants and kept the paychecks coming, without worrying too much about what it all meant. It was safer to write papers and textbooks about things that everyone agreed they knew than go dragging up awkward questions whose answers might contradict what people in other departments were saying they knew. Before long the whole edifice would be threatened, and the result would be trouble from all directions.
“There must have been something vastly different about the whole reality that existed then,” Vicki said distantly. “I don’t mean just with the dinosaurs, but about everything: the plants, the insects, the marine life. Walk around the museums and look at the reconstructions. It was all on a different scale of engineering. You can’t relate it to the world we know today. Something universal has altered since then. And the only thing that makes sense is gravity. Earth’s gravity must have been a lot less back in those times than it is now.”
Keene looked at her, coming back from his own line of thought. His brow creased. “How?”
“I don’t know. But if it wasn’t, dinosaurs couldn’t have existed. Yet they did. So what other explanation is there?”
Robin massaged the hair at the front of his head in the way he did when he had some way-out suggestion to offer. “I can think of one. Maybe it wasn’t Earth’s gravity that was different,” he said.
“Huh?” Keene frowned. “What else’s, then? I mean, where else are we talking about?”