Quantum mechanics ... allows the existence of pure states of composite systems for which it is not possible to assign a definite state to two or more subsystems. States with this property are known as entangled states.
"General Monogamy Inequality for Bipartite Qubit Entanglement"
Tobias J. Osborne, and Frank Verstraete, (7 June 2006)
"It's not rain."
"Excuse me?" Jack didn't look away from the droplets which spattered in strands of silvery gray before disappearing against equally gray clouds.
"That is not rain. It's actually helium precipitating out of the atmosphere."
"Precipitate. Sounds like rain to me." Jack was pretty sure he recognized his self-appointed meteorologist -- he was that Czech scientist Jack had met three years ago in Antarctica.
"I should have been more precise." Dr. Zelenka inclined his head slightly in Jack's peripheral vision. "The droplets we see impacting on the forcefield are not water. A curiosity, given that the clouds directly above Atlantis are water ice. But the surface temperature here is 250 kelvin, so liquid water would be an impossibility, of course." He laughed a little.
"Of course." Scientist humor was the same across the universe. Jack pushed away from the balcony and turned to walk back indoors. Dr. Zelenka pattered along at his side, still talking.
"Fifty kilometers up the clouds are made of ammonium hydrosulfide ice, and beyond that is the methane haze which obscures all views of the planet's surface and which we believe will conceal us from Replicators and Wraith indefinitely."
Jack shoved his hands in his pockets to hide his fists. "And that's why you're here." He kept his voice calm. "Because this planet is such a great bolt hole."
Dr. Zelenka just looked at him, as wide-eyed and guileless behind his glasses as Daniel Jackson himself. "No," he said plainly. "We are here because we dropped out of hyperspace and had nowhere else to go. Would you like to join us for dinner? I believe tonight is taco night."
"Taco night. Yum."
"Since the botanists have begun growing cilantro, the salsa is not that bad."
Jack didn't suppose he was likely to get a better offer.
For a moment when they reached the mess, Jack actually thought he saw Daniel sitting between Teal'c and Vala. He started for the table with a murmur of vague apology to Dr. Zelenka, who was still piling the advertised salsa high on his own plate of tacos. After only a couple of steps, though, he realized that was the back of Mitchell's head, of course, not Daniel's at all, but by that time Vala had already spotted him. "General!" She waved gleefully. "It's taco night!"
"So I've heard." Jack carried his tray over and sat down across from Teal'c who inclined his head slightly. Mitchell stood up until Jack nodded for him to sit down again.
Vala bit into her taco with vigor, crumbling slightly stale, fried corn tortilla all over the table. "Oops," she declared, not particularly penitently.
"So, T., city of the Ancients at last," Jack said. "Is it living up to your expectations?"
Teal'c considered the question very seriously. "As striking as the architecture is, I confess I find many of the decisions made by the Ancients to have been disappointingly selfish and petty. At least to extent they may be judged by the artifacts they left behind."
"You know, I probably can't disagree with you there," Jack said, and proceeded to take his own monstrous bite of taco. The shell shattered spectacularly, raining processed cheese food, suspiciously-seasoned ground beef and shredded, hydroponically grown lettuce down all over his tray, including on his slice of red velvet cake.
"Think I preferred the view last time I was here," Mitchell drawled. Jack picked ground beef and lettuce off his cake as Mitchell went on, "You should have seen it before they took this show on the road, Teal'c. A sunset to die for every night right off that balcony. The sound of the ocean lapping against the pier. Blue sky overhead. Now, you've got a sea of liquid hydrogen lapping against the forcefield and an impenetrable cloud cover. And it never stops raining."
"It's not rain."
"Those aren't rain drops," Jack said around another mouthful of taco. Dr. Zelenka had been right. The salsa was pretty good. "That's helium precipitating out of the atmosphere."
"Yes, sir," Mitchell agreed. "But damn if it doesn't look like rain. Did you know there are more than twenty moons circling this planet? Not that we'll ever see one from Atlantis. And even though we're so close to the south pole the auroral curtains are right over our heads, you can't see that either. You should go up in a puddlejumper, sir. Hanging around down here is like being trapped inside on a rainy Sunday afternoon."
"Monday," Jack said automatically. He thought to himself that he should really stop contradicting every word out of Mitchell's mouth.
But when Mitchell asked, "Monday?" Jack explained anyway, because this wasn't really him being bad tempered; this was the plain truth. "Rainy Sundays are OK because time seems to stop. Like Monday will never get here at all." Jack trailed off, considering his second taco. Wondering if he should skip straight to his cake. Thinking that if it had been Daniel sitting across the table from him, he wouldn't have been waiting so respectfully for Jack to finish his thought.
"But a rainy Monday," Jack said at last, mostly so Mitchell would stop looking at him. "That's like being trapped at the bottom of a goddamned well."
Huh. That had come out a little more vehemently than he'd intended.
He glanced up to see Mitchell's lips tighten, and he thought for a moment Mitchell might actually disagree with him. Before it could happen, Vala interrupted. "The Tauri are really unique in their insistence that time be measured by rotations of their home planet around their solar system's star. You people, you dart out across galaxies, you cross times and dimensions and universes, and you can still argue about the day of the week."
Mitchell started as though she had slapped him. "Metaphorically, Vala," he said controlling the expression on his face with an effort. He even managed a grim-faced smile. Jack concentrated on his cake.
There was a bustle of noise and movement from one of the entrances to the mess. Jack looked over and saw McKay and Sheppard. Apparently taco night was quite the draw. They were making slow progress because Dr. McKay was in the middle of a complicated, emotional explanation about something or other, and he kept stopping to wave his cane around to emphasize the important points. Colonel Sheppard repeatedly backed up to avoid being conked on the noggin.
"Will nothing shut that man up?" Mitchell asked the table, but he kept his head and his voice down as he said it. McKay seemed to be moving pretty well, at least when he remembered to walk instead of argue, using the cane more for balance than support. Sheppard fixed a tray of tacos for McKay and carried it to a table of blue-jerseyed scientists, seeing McKay comfortably settled in with his dinner before returning to the line to fix his own plate. McKay never stopped talking throughout his change in audience, although Jack saw Dr. Zelenka interject an apparent point of contention, only to be mowed over by the human steamroller that was Dr. Rodney McKay.
Sheppard spotted Jack's table, and after a only a moment of hesitation he carried his own tray over. "General," he said, that old, easygoing grin only slightly marred by the rumpled scar tissue that crossed his left cheek from temple to jaw. "I haven't had the chance to tell you how good it is to see you back in Atlantis. Mind if I join you?"
"Please," Jack said around a mouthful of cake. It was everything he'd hoped, overly sweet, with the unmistakable flavor of too much red food coloring. It tasted like Earth.
"Colonel," Sheppard acknowledged Mitchell as he pulled up a chair. "Ms. Mal Doran. Teal'c. I hope you've been enjoying your stay."
"I was just telling Teal'c, there've been some changes since the last time we were here," Mitchell said.
Vala waved her fork around. "It's funny how muted the colors seem. I suppose it's just the different planet but my memory of Atlantis was somehow much brighter. Or something. Or is that just me?"
"It's not just you," Mitchell said. "The whole city feels like a rainy Monday afternoon."
Sheppard smiled before shattering own taco spectacularly with his first bite. "Damn, I forget how messy these things are. Actually, though, it's not rain."
"So we have been informed," Teal'c said. "Helium."
"Well, right, it's helium," Sheppard agreed, looking a little disappointed. Then he brightened. "But you're right about Atlantis feeling damped down. McKay and I have been arguing about it. I think it's the ghost ZPMs we're using to power the shields. McKay tells me we're running on more power now than he ever expected to see after Arcturus, and not to call them ghost ZedPMs. Then he tries to hit me with his cane."
Carter and Dr. Lee had been calling them ghost ZPMs, too. They stopped when word about the mission got back to Earth.
"When you think about it, it makes sense," Sheppard was insisting. "First of all, hitting somebody is no way to win an argument, and secondly, come on, Atlantis is nothing but potential energy. I'm serious. Think of it as Atlantis = mgh where m is mass, g is the gravitational acceleration of the planet we're sitting on and h is obviously the number of hot ZPMs we've got running the show here. Mathematical proof the nature of those ZPMs affects everything else."
Mitchell and Vala exchanged a glance. Then Mitchell said, "Have you considered the possibility that you're spending way, way too much time with Dr. McKay?" and Vala said, "Hot ZPMs?"
"I just added that so the initials would work out right," Sheppard confessed. "And yes, Colonel, you're probably right about that, too, but the guy saved Atlantis. Again. So I'm inclined to cut him a little slack."
"Even when he hits you with his cane?" Vala wanted to know.
The easygoing smile smile slipped a little. "Especially then," Sheppard said, and concentrated on gathering up the shards of his taco.
A brief silence. Then Mitchell said, "I was just telling the general about the view above the cloud cover. He should get up in a puddlejumper to see the auroras."
Sheppard snapped his fingers and pointed at Mitchell. "You know, that's a great idea. We can't let General O'Neill report back that it's all storm clouds and ghost ZPMs on Atlantis these days. The team's going to be on stand down for a little while now, so just name your time, General. I'd be glad to go up with you."
"It looks like no one told Daniel it was taco night." Jack abruptly pushed himself away from the table even though he still had a bite or two of cake left. "I should probably go find him before they run out of fresh salsa. Colonel Sheppard, I appreciate the offer."
"Yes, sir." Sheppard's smile didn't waver, and he and Mitchell both stood.
"Actually, I did tell Daniel tonight was taco night," Vala said rather plaintively. Jack didn't look back, but Mitchell caught up to him as he left.
"Sir," he said.
"Colonel," Jack replied, but didn't stop. Mitchell was stubborn, and Jack let him dog his steps until they were well away from the mess, in one of Atlantis' broad, open breezeways. The cloud-choked skies above made the stained glass colors seem thick and sodden.
"General," Mitchell tried again. "A word, please."
It was a little undignified, being hounded down the corridors like this. Not that he generally noticed that sort of thing. Jack sighed and finally stopped, wondering if it was his age or his rank that was catching up to him. "Something on your mind, Colonel?"
"Sir, the way the mission turned out. I want you to know that I take full responsibility."
"Colonel Sheppard was in command."
"Yes, sir, and he has -- he continues to have-- my full confidence. All the evidence indicates he did everything humanly possible to accomplish the mission's objectives. "
Jack waved one hand above his head, fingers fluttering a bit to indicate the wide open corridor, the stained glass, the arching struts and all of Atlantis around them. "The city's still here, safe and sound. Sheppard brought everyone back, just a little worse for wear." Jack couldn't help the way his mouth twisted at that, but he recovered. "So I'm wondering what, exactly, it is that you're attempting to take the blame for."
Mitchell stood painfully straight. "Colonel Sheppard asked for Dr. Jackson's assistance, but it was ultimately my decision to allow him to go."
Jack shook his head slightly. Mitchell didn't know Daniel as well as he thought if he really believed that.
"Given Origin's interest in Dr. Jackson, I honestly believed he would be safer in the Pegasus galaxy."
"What is it, two years you've had Daniel on your team?" Jack knew perfectly well just how long Cameron Mitchell had been leading SG-1. "And you thought shipping him off to another galaxy would be enough to keep him out of trouble? I'm disappointed, Colonel. I thought you were a little quicker on the uptake."
Mitchell finally relaxed slightly, shaking his head. "Well, no, sir. I guess I'm still something of a dreamer."
Jack couldn't hold that against him. "If we were any of us were just good airmen, we wouldn't be here in the first place."
"Yes, sir." Mitchell took a deep breath. "Thank you, sir."
Mitchell finally left him alone and Jack made his way to the tower room, though he stepped out on the balcony before going in to see Daniel. From this height, the lights of the city twinkled like somber Christmas decorations. The helium droplets overhead looked less like rain from this perspective and more like fat snowdrops as they hit the shield.
The door parted for him before he could knock. Daniel started in surprise, then rolled his head around to see his visitor. "Oh. Hello, Jack."
"You're missing taco night."
"So I heard." The only light came through the open windows on all sides, the lights of Atlantis reflecting off the clouds. It was enough for Jack to see Daniel's quick smile. "Seemed like it would be a little -- uh, overly crunchy for me. Maybe next time."
Daniel had already tried to explain the way sharp sounds and sensations affected him these days. A fluttery, lightning-bright filament sparking behind his eyes, in the fillings of his teeth, in the beds of his nails and the roots of his hair.
Jack supposed he could see how tacos might be a bit much. "Did you get any dinner?"
"Cup of chicken soup and a soggy grilled cheese sandwich about an hour ago. No one's going to let me starve. In fact, I'm even perfectly capable of getting my own dinner."
"Right, I know. Just checking."
"I'm fine." Daniel spread his arms wide. "See?"
And he was right; he looked all right. Hair was a touch longer, and to Jack's eye he'd lost some muscle mass. But he seemed OK.
Jack found his way to a sleekly carved bench under one of the windows. Daniel didn't say anything to fill up the silence that began to stretch between them."Oh, hey, I'm sorry about the door," Jack finally blurted. "Didn't mean to just bust in on you."
Daniel snorted softly. "Don't worry about it. Atlantis loves you. The more I read about the Ancients, the more surprised I am that those of us without the gene can live here at all."
Daniel had been slated to receive the gene therapy after the mission with Sheppard. It wasn't so much an option anymore.
"What? You're kidding. Not even a formerly ascended is good enough?"
Daniel sounded reluctant. "The truth of the matter is, the Ancients seem to be have been a xenophobic gang of bastards. I don't say this about many species, but sometimes they almost make humans look good."
"That is saying something. So is all this meaning of life stuff is turning out to be a letdown?" Jack gestured towards the library interface.
"What? No, I'm not saying that at all. In fact, I'm starting to think our entire understanding of Ancient is based on a fundamental failure to get the way they used language in the first place. It's no wonder we've been having so much trouble searching their records. We've been stumbling through metaphors and incredibly clumsy approximations with no sense at all of what the Ancients actually meant by the transfer and dissemination of experience."
"Um. All right. So they're not bastards?"
"No. I'm pretty sure they were." Daniel's shoulders slumped. "Just, it's going to take me a while to figure out what they actually have to say for themselves."
"Months. Maybe years. Hey! Good thing I've got time."
"Yeah. About that. Look, I hate to bother you with personnel issues--"
"Personnel?" Daniel scrunched up his face. "I don't have anything to do with personnel. Jack, you don't have anything to do with personnel issues."
And Daniel was right. Jack didn't. Except when he did, like tonight. "Colonel Mitchell seems to think I blame Sheppard for the way the mission turned out. Any reason why I would do that?"
Daniel looked more puzzled than ever. "The mission was a success. We came back with the coordinates for nine ZPMs. Atlantis has enough power to remain here indefinitely. I don't understand. Isn't it a good thing if John Sheppard gets credit for saving Atlantis?"
"I think he means, what happened to you." Jack said plainly.
"What happened to -- Oh." Daniel finally got it. Just being the sharpest linguist in two galaxies didn't mean he was particularly good with words. "But Jack, you know and Cam knows what kind of a mission this was."
Yes, Jack had known. An idiotic one. Lunatic theories from the McKay siblings, aided and abetted by Carter who really, Jesus, should have known better. But faced with losing Atlantis they had done it anyway.
ZPMs were, by their very nature, in a superposition of states. Ergo, as Carter had explained very carefully to Jack, if no observation was performed on a ZPM, it didn't fall into a determinate state, and it should be possible to take ZPMs from other universes without, in fact, removing them. A spectacular entanglement of qubits whereby each ZPM would be simultaneously here on Atlantis and back where the mission had found it.
Both here and there. Hither and yon. Alive and dead.
Just like Schrödinger's Cat.
A shudder ran down Jack's spine, and he said quickly, "So, you don't feel like Sheppard is responsible for --" He trailed off, gesturing vaguely in Daniel's direction.
"I just told you, Jack." Said in Daniel's patient voice, which of course was the very antithesis of patience. "What? Do you feel like John's responsible?"
"He is responsible. It was his mission. But do I blame him?" Jack shook his head. "No."
"Well. OK, then." Daniel still sounded a little confused. "As far as I can see, nobody is blaming anybody for anything and the problem's solved. Oh, wait a minute. You think Cameron is feeling guilty? That doesn't make sense either. Honestly, Jack. All these years dealing with you soldiers and it never gets any easier. I'll talk to him."
Jack was going to correct Daniel about the military and then thank him for volunteering to talk to Mitchell, but as Daniel started to stand up, he suddenly said, "Ah," and sank back into his deeply padded chair.
"I'm fine," Daniel answered reflexively. "Just give me --" He curled into himself, shoulders hunching.
"Yeah, all right," Jack said, moving forward as he spoke. "Take it easy."
"I am, I am." Daniel panted the words, both hands clenching into fists on his knees. Jack maneuvered awkwardly, his own knees being none too helpful here, managing to crouch in front of Daniel's chair and then finally just sitting on the floor at Daniel's feet. He cautiously petted the back of Daniel's calf, feeling the muscles tensed and twitching even through the material of his pants leg.
"Try to relax. You're OK. Do you need me to call the doc?"
"No. It's not bad. Just --" Daniel started to straighten up, his eyes still squeezed shut. He whimpered, not too softly for Jack to hear, and flung out one hand to grab Jack's collar. His twitching fingers knotted into a fist and his forehead came down to rest on Jack's shoulder. "I'm OK," he chanted, and all Jack could do was hold himself very, very still.
After a moment more the tension slowly drained from Daniel's body. He fell silent, and his knotted fist relaxed. He was mumbling some words Jack couldn't quite hear and oh, hell, he was falling right out of the chair. It was a slow collapse, shoulders rounding, spine twisting. Jack caught his shirt awkwardly and tried to prevent Daniel's knees from hitting the floor too hard as he came down. He wound up half- sprawled over Jack's lap, his head resting on Jack's chest and his long legs tangled in the legs of the chair. "Careful, there," Jack whispered, patting his cheek and then easing Daniel's glasses off his nose to tuck them into his own shirt pocket. Daniel's face was wet. "Don't want to break these."
After another long minute or two Daniel's breathing began to even out. Jack rested one hand on his back, finding Daniel's shirt soaked through with sweat. Daniel made no attempt to move and neither did Jack. Finally Daniel muttered, "Think I finally remember what this reminds me of."
"Yeah?" Jack stroked his back in careful touches, figuring Daniel would tell him if the stimulation was too much.
"Yeah. It's a little like coming down off Thorazine after, you know. Ma'chello's little bugs."
"Shit, Daniel. I didn't realize it was that bad."
"It wasn't. Well. It wasn't fun, but they gave me dopamine agonists for a few weeks and that helped with the worst of the symptoms."
"And they can't do that now?" Jack already knew the answer.
"Given the mess my neurotransmitters are in, they'd rather not risk it."
Jack moved his hand up and carefully and brushed the hair back off Daniel's forehead. Daniel flinched and Jack froze. "This OK?"
"It's OK," Daniel reassured him. "Feels good."
"All right." Still, Jack waited a long minute before he went back to running his fingers carefully through Daniel's hair. "They giving you anything for the pain?"
"It's not pain." Daniel's voice was slow and comfortable. "Just distracting, really. Hearing myself blink. The flashes I see when my muscles fire. All the stuff going on in my brain. Like summertime storms with heat lightening in the distance. It's funny."
But Daniel didn't answer, and Jack could hear his breathing slow into sleep. Well, hell. This wasn't exactly comfortable, but he couldn't begrudge Daniel the few moments of peace.
Besides, he was selfishly grateful for the weight of Daniel's body in his arms. It was impossible to doubt Daniel's presence with his head resting heavy over Jack's heart.
It was no surprise that after the first eight ZPMs had been gathered almost without a hitch, the ninth had been the one to blow up in their faces. Well, not a literal explosion. Jack didn't have the math to describe what had literally happened, but Sheppard had nearly lost an eye, Dr. McKay had come within minutes of bleeding out from a punctured femoral artery, and Daniel --
Daniel hadn't come back at all.
Except that of course he had. He was right here, uncomfortably heavy, one hard kneecap putting Jack's left leg to sleep. Large scale systems (like, say, the archaeologist asleep in Jack's lap) were not indeterminably probabilistic, so if he was here he was not also scattered through the universe where they had found the last ZPM.
Although maybe he was, and everyone was being exquisitely careful not to put the matter to the test. Daniel would never step through a Stargate again. Never travel through subspace. The doctors wouldn't even subject him to an x-ray, far less more sophisticated imaging techniques. Nothing which could measure Daniel too precisely. Nothing which would insist upon his occupying specific space at a specific time. The scientific consensus was that it would safest for him not even to use Atlantis' elevators.
No one really knew for sure, but Drs. McKay and Zelenka hypothesized that Daniel was still alive because his mental wave functions hadn't collapsed into one state or another. The key, then, was to avoid performing an observation of him in the quantum sense.
And because no one really knew what that meant, they were tiptoeing around every other sense as well.
Daniel seemed to find the whole thing hilarious. And inevitable. "I've been the invisible archaeologist for the past decade anyway. I shouldn't be surprised that the universe itself has finally made it official."
Jack thought about Daniel trapped on this rainy Monday afternoon of Atlantis for the rest of his life, and felt as though his heart would break in two.
He continued gently stroking Daniel's hair, his other arm around Daniel's shoulders, and after a few minutes Daniel snuffled against Jack's sleeve and cautiously tried to sit up. "Take it easy," Jack said, helping. "There's no fire."
"Oh, god. I'm sorry, Jack. Was I asleep for long?"
"No time at all. I was just making my retirement plans."
"Retirement --? Don't be an ass. You can't retire on Atlantis."
"Sure I can." Daniel was making no attempt to get up, so Jack scooted back carefully until both of them were leaning against one of the window benches. "With nine ZPMs I'm pretty sure there's enough power to maintain at least one more retired Air Force general with bad knees. I don't see the problem."
"You can't retire here," Daniel repeated mulishly. "There's no fishing."
"No mosquitoes either." Jack waggled his eyebrows. Daniel just shook his head, eyes closing, and Jack reached out and caught Daniel's chin between his thumb and forefinger. "Hey, professor. Look at me here."
Daniel's eyes opened reluctantly and Jack gentled his hand to stroke Daniel's cheek with the side of his palm. "You think I didn't know I would end up marooned on Heliopolis with you sooner or later, Dr. Jackson? The past decade, I've just been biding my time."
"Idiot," Daniel said wearily, but he let his head rest once more on Jack's shoulder, and somewhere far overhead, the light of twenty moons shone down upon an impenetrable methane haze.