“Seriousness?” Natasha’s voice was curious. “Don’t they know what seriousness is?”
Bernie groaned. Then headed back to face the brain cases.
* * *
“Bernie Janovich, what is the center of gravity?” Petr Nickovich had been waiting impatiently while Bernie was out of the room. His English was not good and the discussion of gravity was more confusing than helpful. He knew there was something there because the notes he had received on flight mentioned gravity regularly. Center of gravity, specifically. He sat and thought, giving no sign how much it hurt him not to understand about gravity and how to fly. Finally, Bernie returned with the letters and Petr asked his question before the sewer system could distract them again.
“Hey, I actually know that one.” Bernie grinned at Petr. “Cars need a low center of gravity for stability.”
Petr just looked at him. As usual, Bernie hadn’t explained anything.
Bernie lost his grin. “Okay. Try it this way. Bend over.” Bernie bent over. “As your head moves forward, your rear end moves backward, otherwise you fall on your face. That’s to keep your center of gravity over your feet.” Bernie stood up again. “Try to balance something on one finger. It’s the same thing. To keep it balanced, you have to keep your finger under the center of gravity.”
“You mean that center of gravity just means the point of balance?” Petr couldn’t help his look of shock. “The place where you would place the fulcrum?”
The outlander shrugged. “Pretty much.”
Petr considered, then asked. “Then why does how high the center of gravity is matter?”
“There is other stuff besides gravity. Centrifugal force and stuff.”
“Explain that, if you would.” Petr tried not to grit his teeth. He knew he was close to something but wasn’t sure what. He listened to Bernie’s rambling explanation. It was there he knew, if he could just grasp it. The secret to everything. It came in bits and drabs . . . gravity was a force like centrifugal force. Then another piece when Bernie squared his stance and had someone push from the side. The person pushing on him to try to overbalance him was a force. The key came when he asked why they used rockets to get to the moon. “Why not wings?”
“No air in space.”
“Why not?”
“Gravity,” an obviously frustrated Bernie insisted.
Petr froze. He could see it in his mind’s eye. “How much does air weigh?”
“I don’t know.” Bernie shrugged. “It’s pretty light; we can look it up. Uh . . . maybe not, but we can write Vladimir about it.”
The outlander didn’t realize. How much air weighed didn’t really matter. What mattered was that air weighed. That it had weight. It was pulled down to the ground by a force; water was, too, but more so. They wouldn’t have to look the weight of air up, Petr could think of several ways to work it out. Looking it up might be easier if it was in one of the books. The important point was that air had weight. That was how the balloons worked. That was how it all worked.
* * *
Vesuvius erupted. Russian words spewed forth. Bernie didn’t understand. Didn’t want to understand after he caught the Russian words for “idiot” and “uncultured” repeated several times. At least this time everyone was an uncultured idiot, not just Bernie. Which was a relief. Everyone, Petr included, everyone from Adam to Aristotle . . . especially Aristotle. Everyone in the entire history of the world, both histories. Only two exceptions could be made: God and Sir Isaac Newton. God for creating such a complex world from such beautiful simplicity and Sir Isaac Newton for understanding it.
“Don’t you understand, you uncultured buffoons? We can fly!”
“What in blazes are you talking about?” Filip Pavlovich was not one to accept being called an idiot by anyone. “Of course we can fly, once we know how. If the outlanders from the future could do it, we can learn to do it.” He froze then. “You know how?”
“It’s all forces, don’t you see . . . damn Aristotle to the worst region of hell. Innate desire. Natural tendency. Bah . . . it’s forces. Water is heavy, air is light, the force of gravity works better on heavy than light, that’s what makes it heavy.”
Bernie almost laughed at the man’s odd combination of enthusiasm and exasperation. “Think you can explain a gravity-feed system to these guys, Petr?” he asked, half-jokingly.
“Da,” followed by about three sentences in Russian said too fast for Bernie to understand. Which led in turn to several voices from around the room saying, “Oh, we understood that part! We thought he was talking about something else.” Bernie just shook his head and left the geeks to their talk. Somehow, he couldn’t stop grinning. These guys got such a charge out of this stuff. Now maybe they could get the plumbing to work.