Disc (13 page)

“We’ll be going some places that are really cold too,” Tiona said. “Can we get coveralls with some kind of heating element built into the inner layer?”

“Oh man, if you try to heat with electricity you’re going to run out of power in a hurry.”

Tiona grinned, “You just don’t know about our power sources yet. Not only will we be able to
heat
our suit with electricity, we’ll carry water instead of compressed oxygen and use electrolysis to separate our oxygen out of the water.”

Nolan turned to Tiona, “Really? Have you run the numbers to be sure that makes sense?”

“Yep, a liter of water breaks down to 600 liters of oxygen, whereas compressing oxygen at 200 bar will only squeeze 200 liters into a liter.”

“But batteries that’ll carry that much power are going to take up more space and add more weight than you’re going to save,” Bob said.

Tiona said, “My dad’s the guy that invented GE’s new hydrogen boron fusion plants. He’s come up with a fusion device about the size of a coffee thermos that’ll generate thirty kilowatts.”

They stared.

Nolan said, “But
still
, the shielding’s got to make it a lot bigger and heavier?”

“Running at low power like that, the fusion reaction doesn’t have enough side chain events to generate dangerous numbers of neutrons.”

Astonished, Bob thought,
Her dad’s the one that invented fusion?!

***

When the door into his basement lab opened, Vaz looked around and saw Tiona coming in. A warm feeling flooded over him and he wondered why seeing his daughter made him feel so happy. It hadn’t always made him feel that way.

Is it because now she likes physics too?
he wondered.

“What’cha working on Dad?” Tiona asked.

He looked around at the series of different size discs he’d laid out on the floor, thinking it had to be obvious. However, Lisanne had told him many times that people sometimes just asked questions to start a conversation. After a brief pause he answered even though he thought Tiona
knew
what he was doing. “Precipitating some new discs.”

Tiona snorted, “I can
see
that! What are the new discs for?”

“Flying car.”

“Oh!” Tiona said, “Way cool!” Vaz thought she probably sounded excited, although he knew he wasn’t good at recognizing other people’s emotions. She looked around and her eyes settled on a box in the corner, “Is that the frame for my flycycle?”

Vaz shrugged, “It’s addressed to you. I didn’t open it.”

Tiona promptly ripped the tabs to open the box, “Yes it is!”

Over the next hour, Tiona quickly assembled the parts of her flycycle, attaching the two nine inch discs side by side behind the bicycle seat. Handlebars were just above the twelve inch disc in front. A collapsible shaft extended down from the bicycle seat to a plate that stood on the floor. The thirty kilowatt fusion generator sat on the plate. A crossbar foot rest was just above the fusion generator. Two small vertically-mounted discs at the front and the back would turn the flycycle right and left as she turned the handle bars.

Though Vaz stayed fairly busy precipitating the discs for his flying car, he kept surreptitiously watching Tiona’s project. As he’d promised, he’d programmed software for the flycycle. Twisting the grips on the handlebars forward sent more power to the rear discs, tilting the flycycle forward and causing it to begin skimming forward. Twisting them backwards sent more power to the front disc. His software stabilized the flycycle by controlling the power to the discs so that no matter how far forward you twisted the grips, the flycycle maintained altitude unless you pushed the handlebars down or lifted them up. Moving the bars up and down increased or decreased altitude. Tilting them side to side banked the flycycle into turns by sending more juice to either the right or left disc in the rear. The rider was expected to both turn the handlebars to one side
and
tilt them to make a good banking turn on the flycycle. However, the software would tend to bank the frame even if the rider
only
turned the handlebars.

Tiona finished assembling the flycycle and to Vaz’s alarm threw her leg over and settled onto the seat. “Wait!” he said, standing. “I made a… a tester for the flycycle.”

Tiona frowned, “A tester?”

“Uh-huh, if you’ll just pull the seat back off.” Vaz picked up an eight inch cube of steel and walked over to the flycycle with it. A camera was mounted above the cube on a tube.

Giving the chunk of metal in Vaz’s hand an odd look, Tiona bent down and loosened the knob that held the seat in place. She pulled the seat off and Vaz settled the cube onto the frame in its place. “How much does that weigh?” Tiona asked

“A hundred and forty pounds. I know, that’s more than you weigh, but it seemed like a good test weight should be a little heavier than you are.”

Tiona blinked a couple of times, “Really? You didn’t look like you were carrying 140 pounds.” She grinned at him, “Are you trying to trick me? I’m not going to find out it’s actually hollow, am I?”

Embarrassed, Vaz said, “Um, I’m… uh, strong. I’m sorry, I’m kind of a freak…” he trailed off.

To his surprise, Tiona stepped to him and gave him a little hug, “Hey,
strong’s
nothing to be ashamed of. Ladies like strong men, you know?” Tiona turned back to the flycycle. Vaz saw her surreptitiously try to lift it. He thought the look on her face might indicate surprise, but wasn’t confident of it. She said, “How are we supposed to test the flycycle with this big chunk of steel on it?”

“Oh, the weight’s supposed to represent the rider’s center of gravity. The tube puts the camera at about the height of your eyes. I’ve got a station over here where you can practice flying it.” Vaz led Tiona over to where he’d installed a duplicate handlebar to the one on the flycycle. It had a viewscreen in front of it. “You can test fly the flycycle without getting injured if you crash it.”

Tiona looked back and forth from the flycycle to the test station. “Are you saying that this test station is wirelessly hooked up to the flycycle?”

Vaz nodded.

Tiona seated herself at the test station and gently lifted on the handlebars. She turned to see what was happening with the flycycle and saw it lifting off the basement floor and rising toward the ceiling. She eased off the pressure on the handlebars and the flycycle stopped and hung about halfway between the floor and the ceiling. Twisting the bars, she watched the flycycle spin around the axis of the seat. She banked it side to side and pitched it front to back, watching it scoot those directions across the floor. “So, you’ve set up the software to maintain the same altitude as I do different maneuvers unless I’m pushing down or lifting up on the handlebars?”

Vaz nodded wordlessly. When the flycycle neared the wall, it pitched itself so that it stopped before actually touching it. Vaz said, “The flycycle’s AI should also keep you from running into things—unless you
tell
it to let you hit them.” After a moment, he elaborated, “It’s got collision avoidance radar like a car does.” He frowned, “Well, actually, it’s better than a car’s collision avoidance radar because it also keeps you from hitting the ground or running into things that are overhead too. I’d programmed software to prevent those kinds of impacts for the flying car, so I just adapted it for the flycycle.”

Turning to look at the video screen, Tiona remotely drove the flycycle around the lab a few times. She turned to her Dad, “Are you thinking I need to practice this more? I don’t feel like I’m learning anything.”

Vaz had been watching intently. Now he said, “No, I just didn’t want to find out there was a controller glitch while you were
on
it. Better to have it crash while you’re driving it remotely.”

“Oh.” Tiona grinned, “Well, I’m taking it out for a ride then.”

“Um,” Vaz said, getting up and opening a cupboard. He looked a little embarrassed, “I made you a safety harness. I think you should wear it when you ride the flycycle.” He shook out a set of straps that looked like the kind of harness that a parachutist would wear. He pointed to a disc attached to the straps, “This is a ten inch thruster that should sit over your shoulder blades. It has one of my new graphene fuel cells inside of it with a 5 kilowatt-hour capacity. It can generate twenty kilowatts for about fifteen minutes, so the disc can produce 200 pounds of thrust for that amount of time.”

Tiona was staring at the harness wide-eyed. Vaz thought maybe she didn’t believe him, so he elaborated, “I know that’s not much, but it has an AI chip that uses GPS to calculate the best way to use that energy to protect you.”

Tiona turned an intent gaze on him, “How do you mean?”

Vaz stared at the harness while he gathered his thoughts for a moment, trying to think how to explain it. He pointed to a large red button set into the front of the harness, “If something happens, of course you can talk to it with your AI, but in an emergency, you could just slap this button here on the chest.” He tilted his head, wondering if she understood. “It’ll have been following your velocity and position by GPS. If you’re falling, it’ll calculate the best way to use its energy to slow you before you hit the ground and will also move you laterally so you come down in a flat area. If you’re traveling at a high horizontal velocity, it’ll use its thrust to slow you down and to avoid objects in your path.” He pointed to a number of small metallic buttons on the harness and said, “Low powered collision avoidance radar units like on a car or your flycycle.”

Tiona took the harness, “How do I put it on?”

Vaz helped her step into the harness and buckle it in place. She reached back and felt the disc which was seated over her shoulder blades as Vaz had described. She frowned, “This is pointed front to back. If I’m falling, it’s not going to be able to slow me.”

“Oh, it’s just held against your back with a Velcro tab at the bottom.” Vaz stepped behind her and jerked the bottom of the disc out away from her mid back. It lifted up until a couple of straps stopped it in a nearly horizontal position. “Here, I’ll lift on it,” he said putting a palm underneath the horizontal disc and lifting it straight up into the air so that Tiona dangled beneath it like a skydiver beneath her parachute. “See, once the Velcro releases, it should hold you up just fine. Just like the saucer, it’s made up of a hexagon of smaller thrusters all wedded into one big thruster. Its AI can tilt it various directions to guide your descent.” Vaz looked at Tiona as she hung there and noticed her eyes were quite wide. He remembered Lisanne telling him that wide eyes could indicate dismay or fear, “Are you okay?”

Tiona barked a little laugh, “Yes, can you put me down?”

“Um, yeah,” Vaz said setting her down. He’d been enjoying the muscular effort of holding her up and had forgotten to consider that she might not like it. “Sorry.”

Tiona shook her head a little, “No problem.” She tilted her head oddly and said, “Holding me up wasn’t… difficult?”

Vaz shook his head, surprised that she would think it would be. “Um, no. You’re
not
very heavy.” He lowered the disc down until the Velcro stuck its bottom edge to her back.

Tiona glanced back over her shoulder, “So, I could tell this thing to give me 100 pounds of lift, then leap way high into the air, huh?”

Vaz gave her an uncomfortable look, “You could, but it would use up some of the power you might need to save yourself if you get in trouble.”

She grinned at him, “Maybe I need to power it with a fusor, huh?”

He frowned, “A fusor won’t fit inside the disc.”

She shrugged, “So, I carry it somewhere else. Being able to fly around in just a harness would be
way
cool.”

He shook his head, “You’ll have a
lot
better control with your flycycle.”

She grinned at him, “Speaking of the flycycle, I’d better go
fly
it.” She turned and picked up the bicycle seat, “Do you mind taking the weight off of it?”

Vaz stepped over to the flycycle, loosened the nut holding the weight to the frame and lifted it off.

Tiona slid the bicycle seat on, tightened its nut, and threw a leg over. She lifted the handlebars and floated up into the air a little ways. She rode the flycycle around in a couple of small figure eights, then settled it back to the floor. She looked oddly at Vaz, “Holding that weight isn’t… making you tired?”

Vaz glanced down, embarrassed to realize he was still holding the hundred and forty pound weight a little in front of him. He’d been mildly enjoying the strain on his arms, but he quickly turned and set it down, “Um, no.”

She got off the flycycle and picked it up, “Well, I’m going to go drive out in the country, looking for a place where I can ride the flycycle without attracting a lot of attention.”

Vaz frowned, “You shouldn’t do that all by yourself. What if you get hurt?”

Tiona gave a little laugh, “Between your collision avoidance radar on the flycycle and the safety harness, that doesn’t seem very likely.”

He shook his head, “It’s new technology. There’s a substantial possibility that something’ll go wrong!”