Diamonds in the Sky (14 page)

Sam was shaking his head, his ears flapping inside his helmet. “If I say black is white, is that subtle?”

“Um—”

“Subtle as a screen door on a submarine.”

“Whoa, boy. Did you just learn that?” The regulator. He should attach the wire to the regulator.

“Never mind. You’re trying to get energy out of that wire. If we see a spark, we’ll know it’s real. But how do we know this
dark energy
is real, for Pete’s sake? I’ll bet even Pete doesn’t believe it.”

“Pete wouldn’t believe it if I told him the sun rose in the east.”

“It doesn’t, on the station. Okay, bad example. But if you’re going to give something a crazy name like dark energy, don’t you at least have to know it’s there? Know something about it?”

“We do know something about it. Can you shove those pliers towards me? We know something’s pushing the universe to expand.”

“But how?” The dog nudged the pliers. “How do we know?”

“Because of supernovas, I think.”

“Supernovas are pushing the universe apart? I love supernovas! They’re so bright!” The dog’s face widened in a toothy grin inside his helmet.

“Supernovas aren’t causing it. Supernovas are how we know.” He paused; Sam looked crestfallen. “They’re like measuring sticks.”

“Okay. Next fable, please.”

“Really — astronomers use this special kind of supernova as what they call standard candles. By observing them carefully, they can tell how bright they are.”

“Well, rruff. What’s so hard about that?”

“Nothing, if the supernova were right next door. Of course, then we’d be toast. But they’re not, they’re off in distant galaxies. Thing is, there’s this special kind of supernova that astronomers know are all pretty much the same brightness really — not just how bright they look in our telescopes — and that lets them figure out how far away the galaxy is.”

“Woofee! They know how far away the galaxy is. I’m so excited I can hardly breathe. Can you see me fogging up my faceplate?” Sam was breathing fast, and actually was fogging his faceplate a little.

“It’s not that easy to measure, you know. They can’t just, like, shine a laser-finder on it.”

“Speaking of lasers, how’s that thing coming? I’ve been watching our rotation, and I think the base will be over the horizon soon.”

Jake flexed his gloved fists, which were starting to cramp up. He wasn’t just wishing he hadn’t taken the detour; he was wishing he’d paid more attention in his electrical classes. He had the laser awkwardly hanging out of the survey scanner. It needed juice from the boat’s batteries, and right now it wasn’t strong enough. “I’m doing my best here. I’m just hoping we can pull enough extra power from that sled to make this laser work.”

The border collie leaned in and licked at him — catching only the inside of his faceplate. “You can do it. Anyway, you’re not fooling me.”

Disconcerted, Jake said, “I’m not trying to fool you.”

“About the galaxy distances, I mean. They could figure it out from the red shift, right? So these astronomers have learned zip, the way I see it.”

Jake sighed, reaching to loosen a connector. “Dummy. Why’d we ever give you dogs voices, anyway? How can you say they’ve learned zip. They’ve learned a lot—”

“Don’t call me a dummy. Or I’ll call you worse.”

“I doubt you even know anything worse.”

“Oh yeah? You pink and pukle son of a Jack Russell—”

“All right. You’re not a dummy. But the thing is, they get a different answer from the red shift. Different from the one they get from the brightness, I mean.” Jake gestured, making a stirring motion. “They put the two numbers in a big equation pot—”

“What equations? You know I don’t like equations.”

“Equations for how fast space expands — from the Big Bang and stuff. They stir these numbers all around, and what they come up with is—” He paused, and squinted at the terminal on the battery regulator. Did he have the right one?

“I’m waiting. Earth to Jake. Please continue.”

“Huh?” The wire slipped out of his hand, and he swore. “Well, it turns out the galaxies are farther apart than they should be, based on how fast space was expanding a zillion years ago, according to the red-shift.” He caught the wire again, and started twisting it around the terminal.

“So?” the dog prompted.

“Soooo … after looking at all this, which at first made no sense, they concluded that the universe isn’t just expanding, it’s expanding faster now than it was before! That’s why the galaxies are farther away than they should be.” He tightened the terminal nut and looked at the spacesuited dog. “So how could that be? How could the universe be speeding up, when gravity is trying to slow it down?”

“Arrr, that’s what I’m trying to ask you — how could it be?” asked the dog.

Jake shook his head. “It’s been half a century now, and they still don’t know for sure. They call it dark energy, but they don’t understand it.”

“Who is this
they
person, anyway?” Sam asked, with a little yip in his voice. “It could be aliens behind it all, making us think this stuff is true. Are aliens the
they
?”

“I don’t think so. Not unless aliens have taken over all the astronomy departments on Earth and the Moon and Mars.”

“Could happen.”

“I suppose it could, yes. But I don’t think it has. Are you keeping track of our rotation for me?”

The dog snapped to attention and peered at the constellations. He hopped up on top of the cockpit. The inertia of his oxygen pack nearly carried him right on over to the other side. “Yes. My friend, if you have laser light, I think we may have a sightline to base.” The dog’s tail wagged slowly in its encasement.

“All right. I need a little more time. Tell me when it’s coming near to overhead.” Jake worked in earnest now, testing the connections with gentle tugs. He took a deep breath and turned on the zeep generator on the mining sled. A meter on the battery indicated a slight charge coming in. Good. Jake turned his attention to the laser dangling out of the scanner housing. It was going to be really hard to aim…

“Shine your light now,” Sam said.

Jake gripped the unit and aimed the laser up. The base should be one of those points of light just south of Altair. He squeezed the switch. A faint sparkle of green laser light shone through floating dust. When the dust cleared from the path, he couldn’t see the beam at all. Determinedly, he swept it around the patch of sky the best he could. “I don’t know if this is—” he began. The power light on the unit went out. He swore.

“Aww,” Sam said. “Grrr. Can you fix it?”

Jake pursed his lips and sighed. “Not enough juice. I guess this quantum-energy thing isn’t really made to be an electrical generator. It makes enough for its own controls, but mostly it just levitates.” He looked up into the black sky, with its sprinkling of stars. “I wonder if anyone saw the laser.” He shook his head and picked up the flares. “We’d better light a couple of these.” Taking two flares, he hiked far enough to place them on a mound for maximum visibility. He lit the flares and then, unimpressed by their red sparkle, trudged back to the boat.

“We’d better keep thinking,” he said, mulling the approaching NEA-238.

* * *

While they were pondering, Jake swapped fresh oxygen and power packs into their suits. He thought briefly of trying to tap power from one of the suit packs. But he was too afraid of draining or blowing the packs. It wouldn’t do any good for them to be seen if they couldn’t last long enough for rescue. They had a quiet meal, of the pasty stuff you ate right inside your helmet. It tasted incredibly good to him right now.

“I’ve been thinking,” Sam said, hopping down from the boat in a graceful arc. He swung his space-helmeted snout toward Jake. “Finish telling me about dark energy, please.”

“Look, I don’t really think right now is—”

“Please. It won’t hurt.”

Jake rolled his eyes. “What do you want to know?”

“Tell me what dark energy is,” said the dog.

“Nobody knows — except that it’s an energy field that’s pushing against gravity.”

“Okay, so it’s a sort of antigravity, right?”

“I guess.”

“And this energy is coming from…?”

“Well, it seems to come from space itself.”

“Like that zero-point stuff you were talking about? Like the levitator uses?”

“I guess. Maybe.”

“Uh-huh.” The border collie cocked his head and grinned. “Rrrrffff! You know something? I think we’ll get to see the sun rise in the west tomorrow, after all.”

“What’s that supposed to mean?”

The dog padded over to the sled and put a paw on it. “Zeep — zero — energy. The levitator pushes things apart — just like dark energy. Right?”

“R-r-right. I guess.”

“Are you thinking what I’m thinking?”

Jake stared at the dog open-mouthed for a moment. “Well, we’ve been through that. It can’t levitate against space. It needs something to repel. And as soon as it gets a few inches off the ground, its power falls way off.” He shook his head at the dog. “It just doesn’t work at a distance.”

“Rrrr. It pushes real hard up close, though, doesn’t it?” The dog was gazing at him intently.

“Yeah, I guess so.”

“Can we try something?” the border collie asked.

Jake shrugged. “All right.”

“Raise that sled up as far as it will go, then throw some sand or something up under it. Right up against the levitator plates.”

“Um — okay.” Frowning, Jake adjusted the sled controls until it was floating six or eight inches off the surface of the asteroid.

“Good. Let’s test Newton’s laws. Got a shovel?”

He looked around and found a small, flat spade. “All right. Let me get some dirt here.” He scooped up some loose dust, then maneuvered close to the sled. “Here goes.” Feeling very awkward, he flung the dirt under the sled, trying to angle it up.

The dirt never touched the levitator plates. Instead, it ricocheted down with a force that made Jake hop back in alarm, and sent a cloud of dust out the sides. The sled bounced up a few feet from the reaction force, then sank slowly back down, bobbing as though on a sudden wave.

“Holy freakin’—” Jake began.

“That’s it! Rruffff! That’s what we have to do! It’s just like a rocket!”

“That’s amazing! But—”

“There’s plenty of dust and loose stuff here.”

“True. But we can’t just stand beside it shoveling sand under, can we?” Jake whispered.

“Maybe we can. Now bear with me on this…”

* * *

Loading the sled with loose dirt was a time-consuming and extremely messy business. But the sled was built for carrying dirt samples, and it came equipped with side panels to hold the loose stuff, and even a transparent tarp to go over it to keep samples from floating away in the microgravity. It had a pulverizing auger aimed down through the square hole in the center of the sled, but the boat’s dying fuel cells didn’t have enough power to drive it.

In the end, Jake shoveled. Fortunately, there was plenty of loose stuff on the surface. The dirt had almost no weight, but it did have mass and inertia, and when he got it moving upward, it tended to keep moving upward. He lost quite a few shovelfuls before he got the hang of lifting and then redirecting it down into the sled. After a while, he clanged onto rock and metal.
Metal! He was right about this asteroid!
he thought. He moved the sled to a fresh patch of loose dirt. Gradually, the sled began to fill up with asteroid dust.

“I couldn’t dig better myself,” Sam said with a woof.

“You’ll get your chance,” Jake muttered, panting from the exertion. He eyed the slowly growing pile inside the sled. They had a long way to go.

* * *

By the time the sled was piled high with asteroid dirt, Jake needed a rest and some food. The sled looked like a loaded cart without wheels, and with a funny-looking post at one end, holding the controls. “Spare supplies next,” Jake said, sucking food paste and water from his helmet dispensers.

“And a name,” said Sam. “It needs a name.”

“You think about that, while I do this.” Jake got busy bringing spacesuit recharge-packs from the boat. He used vacuum-grade duct tape to hold everything to the control post, including the remaining flares. Then he levitated the sled again and used a lot of duct tape to secure a couple of clipboards and his shovel at an angle to the unused auger, where it extended downward through the square hole. Jake stood with his hands on his hips, studying his handiwork. The shovel and clipboards were pretty crude; but they only had to withstand comparatively minor forces, deflecting the dirt sideways under the levitator.

“All we really need to do, right, is get off this rock and get headed in the right direction toward base. When we get closer to home, they’ll be able to pick up our suit-comms and flares. Right?”

“Right,” answered the dog. “And you found iron and nickel here, so maybe they’ll forgive you for being so boneheaded.” He paused. “Get it? Boneheaded?”

“Yah,” Jake said wearily.

“Wouldn’t it be funny,” Sam said, “if, after all this, they came right here and rescued us?”

“I wouldn’t mind a bit,” Jake said, yawning. He needed some sleep. They only had about eight hours until asteroid NEA-238 would loom very fast. But they couldn’t try anything until this asteroid had rotated to the proper launch position, with the base-station above the horizon. So in their urgency to get off this rock, they had four hours to kill.

“I don’t know about you,” Jake said, “but I’m bone tired. Let’s get some sleep, okay?”

“Bone-tired, rrrff,” said Sam. “All right, let’s rest.” That said, he turned around a few times before settling down. A minute or two later, he was sound asleep.

It took Jake a little longer.

* * *

In the morning, they woke to the stars circling overhead, and the sun disappearing behind the asteroid horizon. They ate a brief breakfast of spacesuit-grade paste. “You look like you’ve been through a mud-bath,” Sam said.

“We’re not going to be a pretty ship,” Jake said, wiping them both down as well as he could. He didn’t care so much if the suits looked dirty, but they needed to see clearly through their faceplates. They were depending on the stars for navigation.