Invaders_a sequel to Vaz, Tiona and Disc

by Laurence Dahners

  Returning to the information she had and using wide ballparks she came up with numbers from three to nine weeks for the daughter-ship to arrive at Earth, depending on actual accelerations and when and how much they decelerated before they got here. She realized that that meant even NASA’s saucer that was way out at Neptune could make the sixteen day trip back to Earth before the daughter-ship arrived.

  She rubbed her temples, hating to think that these aliens could have traveled from another star to start a war, but deciding that if that was their intent, failing to recall the saucers that Earth might need to defend itself would be far worse than just regrettable. She sent messages to GSI’s two saucers out at Saturn and the one that was tracking a comet, telling them to return. She sent another message to General Stoddard, this time suggesting that he might want to request that NASA bring back the saucer from Neptune.

  She was sitting with her mind churning when she got a call from Stoddard. “Why do you think we need NASA’s Neptune saucer?” he said without preliminaries.

  Heavily, she said, “I don’t even want to think that these aliens are here to attack us, but if they are—and we need to fight—the saucers are going to represent our best weapons. I’d hate to think that Earth might die because we didn’t want to disturb NASA’s Neptune mission.”

  Stoddard snorted, “My God, you’re even more paranoid than I am. Would that saucer actually be back in time to make a difference?”

  “Probably, but it depends on those daughter-ship velocity and acceleration figures I asked you for.”

  “Daughter-ship?”

  “We need to have some name for the aliens’ two ships besides ‘the big one’ and ‘the little one.’ To myself I’m calling them the mothership and the daughter-ship, but if you’ve already got designations for them I’ll start using whatever you’ve assigned.”

  “Mothership and daughter-ship it is. I’ll have Major Vincent send you those acceleration figures. Get back to me with your interpretation of what they mean.”

  While she waited for the numbers, Tiona started wondering how the aliens had gotten here from wherever they’d come from. Remembering that her father had been trying to design an interstellar probe she decided she should talk to him. For a moment she considered trying to call him, but then decided, Trying to talk to Dad about something like this over the phone’s impossible. I’ve got to go talk to him in person.

  She was walking to the car when her AI chirped to tell her that Major Vincent’s estimated acceleration figure for the daughter-ship was 0.005 G. She got the AI to do some calculations and decided the daughter-ship was about twice the mass of one of the old space shuttles. She called Stoddard and let him know that the Neptune saucer could be back in plenty of time.

  As her car lifted into the air she thought about the fact that there was no way a plasma drive could lift the daughter-ship back to orbit if it landed. In fact, it shouldn’t be able to get back to orbit with chemical rockets either since it wouldn’t have boosters like the old space shuttle had. If they had something better than chemical rockets or plasma drives, such as thrusters, she couldn’t imagine why they weren’t using them. She put in a return call to General Stoddard, “The daughter-ship could get here in 10 to 20 days if it’s going to fly by. If it’s going to decelerate to orbit it’ll take 3 to 5 weeks.”

  She and Stoddard talked briefly and she confirmed they could have a saucer in four days.

  She rode on in silence, but before she could give the whole problem much more thought, Rob’s return message came in. “Tiona, we’re disengaging like you asked, though it’ll be a terrible waste. We’ve got this thing up to fifty-seven kps. I assume you’ll let us come back out in another five weeks to decelerate it into Earth orbit so the entire mission isn’t wasted, right?”

  She replied, “I hope so. I’ll tell you what this is all about when you get here.”

  Tiona opened the door to the barn and stepped inside. As she started across the barn floor to the stairs that led down into her dad’s workshop she stopped suddenly and stared at the small saucer sitting there. We’ve got another deep space capable saucer that I’ve just forgotten about!

  She went over and walked around it, thinking. She didn’t think it was what the general had in mind, it wouldn’t carry a lot of men. However, it would make the trip to scout the aliens and could take a few people. She wondered what kind of condition it was in, Dad’s usually pretty compulsive about keeping things maintained…

  Before she went down the stairs into Vaz’s laboratory she asked her AI to see if it could contact General Cooper, someone she thought of as a friend and someone who could help her deal with the military. He wasn’t immediately available, but his AI promised a call back.

  In the basement, to her surprise, Tiona found her father apparently disassembling a wheelchair. He was focused enough that he didn’t hear her enter so she watched for a moment, thinking that she should be able to figure out what he was doing. He kept turning to look at some of his big screens which were displaying stills and vids of people using wheelchairs. A couple of the screens had diagrams of several different types of wheelchairs on them. Giving up on understanding without asking, she said, “Hi Dad, what’cha working on?”

  His head turned suddenly to look at her. He smiled, stood and turned toward her, though he didn’t approach. She knew that stopping what he was working on and giving her a smile represented an enthusiastic “Hello” for her father. As she frequently did, Tiona wondered whether she should just accept the fact that this was his version of a loving reaction. Instead, as she usually decided, she gave him the enthusiastic response that fit her world by stepping closer and giving him a hug. Knowing a return of the hug was expected, his arms stiffly encircled her. He gave her back a couple of clumsy pats. When she stepped back, he responded to her question, “Learning about wheelchair technology.”

  “Why?”

  “Lisanne took me into town with her last week and I saw a young man in a wheelchair. He had to make a long detour to reach the curb cut to the sidewalk.” He shrugged, “I think they should be using wheelchairs with lift discs.”

  Tiona felt a tingle of goosebumps. It seemed so obvious! “Oh! Of course!” She exclaimed, “Not just for getting over curbs, but for going up and down stairs!”

  “Yes,” Vaz said, frowning. “Also, people who use wheelchairs apparently don’t like being down at such a low level. They… don’t like everyone else looking down at them…” Vaz frowned at her, looking puzzled. “Do you understand why?”

  Understanding other people’s feelings was a difficult thing for Vaz and Tiona was surprised he was even making the effort. After a moment’s thought she said, “I think it’s because being ‘above someone’ is a position of power. If you’re always having to look up at other people, it puts you in a subordinate social position. If I were in a wheelchair I think I’d prefer to be able to look people in the eye too.”

  Vaz said, “Oh,” though Tiona wasn’t sure he really understood. “Well, in a lift chair you could just set the HAAT so that your eyes were at the same level as everyone else’s.” He shrugged, “It would make it a lot easier for you to get around too. Curbs, stairs, getting in and out of cars…” he looked a little puzzled to Tiona. “It seems that wheelchair-bound people would like that, wouldn’t you think?”

  “Oh yeah!” Tiona breathed, with a feeling of awe for just how much she thought they’d like it.

  He tilted his head, “Why hasn’t anybody made a wheelchair like that already…?” He stopped abruptly, a look of concentration on his face, “I guess it wouldn’t be a wheelchair anymore…”

  “People just don’t think of things.” Tiona shrugged, “Even things that seem obvious once somebody else thinks of them. And, if someone did, they might not have had access to discs, nor known how to get batteries or fusors for them or how to program the chairs to be stable and easily controlled.” She stopped at the doubtful look on her father’s face, “I know all that seems easy to
you, but trust me, most people find it pretty difficult.”

  “Can you help me figure out what they’d really like? You know how I might come up with something…” he looked uncomfortable, “that makes people angry.”

  This query brought Tiona crashing back to reality, “I’d love to. But I came out here to talk to you about a much bigger problem. Is the saucer upstairs still spaceworthy?”

  The non sequitur didn’t phase Vaz. “It should be. I’ve upgraded almost all of its systems to match the newer saucers.” He frowned, “I haven’t over pressurized the cabin recently to test the seals. I’ll tell its AI to start doing that right now.” He mumbled quickly to his own AI, then evidently felt the need to explain, “I keep it up in case we need it to escape from someone like we had to before.” He got a curious look on his face, “But I haven’t been thinking that we’d need to go into space to get away.”

  Tiona waited for a second, thinking that Vaz would ask her why she wanted to go into space, but apparently that question wasn’t one that interested him. She said, “I came out to the farm so I could ask you some questions, but the topic’s supposed to be a secret so I have to ask you not to talk to other people about it.”

  “I don’t talk to other people. Just family.”

  “You talk to Reven.”

  Vaz looked surprised, “I forgot about her.”

  “And sometimes Mom makes you talk to other people.”

  He frowned, “You’re right. But I won’t talk to them about… whatever it is.”

  “There are some aliens in the system.”

  “Illegal aliens, like from Mexico?”

  Tiona snorted with surprise, “No, from another planet.” Deciding he might misinterpret that too, she said, “From around another star.”

  For a moment, her dad’s eyes rose to meet hers. Though they dropped again immediately, that was about as big a sign of surprise as she’d ever seen him make. “Which star?”

  “We don’t know. Nobody saw them enter the solar system. I thought I’d come ask you about it because you were trying to set up a thruster driven probe to go to another star. I know you said it was going to be problematic because of the radiation generated as you neared light speeds, but I don’t know if you ever solved that problem or actually sent a probe?” Suddenly Tiona’s stomach sank as she wondered if the reason the aliens were here was because her father had actually sent a probe to another solar system and they’d come to investigate the place it’d come from.

  Vaz shook his head, “There’d be way too much radiation from hitting interstellar hydrogen when the probe got up to significant fractions of c. The electronics of the probe would have failed.”

  To be completely sure, Tiona said, “So you never sent one?”

  “No.” Vaz glanced at the wheelchair, looking as if he might be losing interest in the topic.

  Tiona felt relief that at least the alien’s arrival wasn’t her dad’s fault. She found it hard to believe he wasn’t more interested in the aliens. Typically he was very interested in any new scientific events. Though not in people, she suddenly realized. She wondered if he wasn’t attentive because he didn’t find alien beings interesting—like he didn’t find people interesting—but would be fascinated if she pointed out some of the questions their arrival posed. “We’re wondering how they got here. No one saw their starship come into the solar system, their ship wasn’t noticed until after it came around the sun on its way back out.”

  Vaz blinked slowly, “How do they know it came around the sun?”

  It was Tiona’s turn to be startled. “Because… it seems to be following an elliptical orbit. We assume it came in on a hyperbolic path, but its close approach to the sun probably did something to alter it into the elliptical orbit that it’s in now.” She shrugged, “Or, they used their drive to alter their orbit into an elliptical one.”

  Vaz looked surprised again, “Why not a deep gravitational wormhole close to the sun? The aliens would have used an elliptical orbit in their own solar system and when they passed through the wormhole they’d have followed that same elliptical orbit out from the sun in our solar system.”

  Tiona’s world underwent a seismic shift. Her initial reaction was to think that her father was speaking gibberish, but she’d thought he was crazy so many times in the past. Growing up with a man who acted so bizarrely, but thought way, way outside the box, had naturally resulted in many episodes where she’d thought he’d lost it. But he hadn’t ever actually lost it, at least as far as science was concerned. “A… wormhole?” she said, “Deep gravitational wormhole?”

  “Oh,” Vaz said, his brow knitting, “I thought I talked to you about wormholes, but I guess maybe I forgot?”

  “What about wormholes?” Tiona said, almost dreading the answer.

  “When I realized that a probe couldn’t survive traveling to another star, I spent some time working out other ways to do it.” He shrugged, “The best way to do it would be to open a wormhole, but they’re extremely energy intensive unless you open them really deep in a gravity well.”

  Astonishment thundered over her. “So… you’re thinking that these aliens… flew really close to the star in their own system, then opened a wormhole from that star to our sun… and came through it?”

  Vaz frowned, “They didn’t ‘fly’ near their star…”

  “Yeah, yeah,” Tiona interrupted, “they followed an elliptical orbit with a perihelion very close to their star, then opened a wormhole?”

  Vaz nodded. “In fact, if you figure out where the perihelion was and draw a vector through the center of the sun and that perihelion, you’ll be able to see which star they came from.”

  Tiona bit her lip as she stared at her father and wondered whether this time he could actually have stepped off the edge of reality. “And you know this is possible? Have you actually done it?”

  He shook his head. At first Tiona felt somewhat relieved. Somehow it was easier to believe that her dad had lost touch with reality than that wormholes existed. Then she realized that it left her with no explanation for how the aliens had actually gotten here. She was opening her mouth to pose another query when he shrugged and said, “Not with the sun and another star. Only between Earth and Venus.”

  Tiona narrowed her eyes, “You opened a wormhole between Earth and Venus?”

  Vaz said, “Yeah, a small one.” He didn’t elaborate.

  Full of questions, but not wanting to overwhelm her father with all of them at once, Tiona closed her eyes, then spoke as calmly as she could, “Why not another star, or Mars for that matter?”

  Vaz didn’t bother trying to look up at her, but recited monotonously, “Wormholes can only be opened at positions of equivalent gravitational potential in the gravity wells of the two bodies. The power required to open the wormhole is inversely related to the gravitational potential, the radius of the wormhole, and the distance between the two bodies.” He glanced up at her. Apparently, even though she was struggling to understand, he decided that she’d followed what he’d said so far. He continued. “A wormhole to the surface of Mars would have to be opened at a high altitude here on Earth so that the gravitational potentials would be the same. Opening it up there would require a lot more power because of the low gravitational potential at that altitude on Earth and because Mars’ gravitational potential is low in the first place. Then, because of the low pressure on Mars, atmosphere would tend to flow from the dense air on Earth to the thin air on Mars so it would be harder to confirm that I’d actually opened a wormhole. Because the gravity on Venus is almost as high as on Earth, I only had to send the saucer up a little ways to match the potential at ground level there. Then, because of the high atmospheric pressure on Venus, as soon as I opened the wormhole, high pressure CO2 vented through the opening in our direction. That confirmed the port had worked.”

  Shaken by her father’s casual description of a world changing experiment that he hadn’t bothered to tell anyone about, Tiona sat silently for a minute.
Vaz had turned back to the wheelchair he was disassembling before she was ready to continue. Finally, she said, “And why not a wormhole to another star?”

  Vaz stopped with a screw partially undone, evidently to think since about ten seconds passed. He said, “I thought about it, but the Venus-Earth experiment confirmed the hypothesis and matched my calculations, so it didn’t seem necessary. Also, because interstellar distances are huge, I’d have had to send the saucer very close to the sun to decrease the energy requirement. That would have required extensive modifications so the saucer could tolerate the heat.” He shrugged, “Essentially, I’d have had to build a new saucer with a much larger fusion plant and big mirrors to reflect away the incoming radiant energy.”

  “But Dad,” Tiona said plaintively, “you’d have opened a portal to another star!”

  He shrugged again, “I know. But once I’d proven it could be done, there didn’t really seem to be much point in actually doing it.”

  Holy Mother! Tiona thought, staggered by the implications. Not just the implications of a star portal, but what her father’s answer said about him and what he thought was important. “Let me think…” she trailed off, trying to come to grips with what it all meant.

  “Is it okay if I keep working on the wheelchair?” Vaz asked curiously.

  Tiona waved weakly, trying to hold distractions at bay, “Sure…”

  Vaz turned back to the wheelchair.

  Several minutes had passed before Tiona turned to her father feeling like her head had just broken the surface of the water. “Dad?”

  He stiffened momentarily, like he did sometimes when he was interrupted in the middle of something. Then he set the wheelchair back down from its tilted position and turned to her. “Yes?” he said, his eyes rising slightly, but not all the way to her face.

  “I should tell you more about these aliens, because I think you may be able to help in… understanding and dealing with them.”