#Space Noise | Explore Tumblr posts and blogs

reasoningdaily · 1 year ago

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In the first few hundred thousand years after our Universe was born, a primordial hum ripped through a plasma of superheated particles. Scientists are listening in with the hope of gaining new insights about the mysterious force known as dark energy.

Before stars or planets, before black holes and white dwarfs, before even atoms or rays of light, the Universe reverberated with something surprising – sound. This primordial hum moved at more than half the speed of light through a superheated plasma of baryons, photons, and dark matter.

It arose from a tug of war between ancient and powerful fundamental forces generating soundwaves in this electrically charged soup of particles. Then, just a few hundred thousand years into its existence, the plasma disappeared like a morning fog. The Universe fell suddenly, and profoundly silent.

Yet, it is still possible to pick up echos of these first soundwaves that spread out across our early Universe – if you know where to look. The ripples they created in the plasma have left a permanent imprint on the distribution of matter around the Universe. And they are also providing astronomers with clues about one of the deepest mysteries of our Universe today, the mysterious force known as dark energy.

The primordial soundwaves – also known as baryon acoustic oscillations (BAOs) – formed as the particles in the early Universe began to be pulled together by gravity.

"The gravitational pull of dark matter in the early Universe created 'potential wells,' pulling plasma inward," says Larissa Santos, a professor at the Center for Gravitation and Cosmology at the University of Yangzhou, China. The plasma, however, was so hot that it also created an opposing outward force. "Photons created radiation pressure that fought gravity, and pushed everything back out again. This fight created acoustic oscillations – sound waves."

BAOs burst outward from uncountable potential wells, forming expanding, concentric spheres of sound energy. They crisscrossed each other, sculpting the plasma into dazzlingly complex three-dimensional interference patterns.

Had a human somehow existed in the epoch of "baryon acoustic oscillations" (BAOs), they would have heard nothing. The sounds were around 47 octaves lower than the bottom note on a piano with enormous wavelengths of about 450,000 light years.

This incredibly deep, inaudible rumble travelled through a medium that even our most powerful telescopes is unable to penetrate. The deeper we look into the Universe, the further back into its history we see due to the time it takes for light to reach us. We can only see so far, however, as the electrical charges from unattached protons and electrons in these early stages of the Universe continuously scattered and diffused light, creating an impenetrably random glow. But BAOs created patterns in this medium which rippled outwards, and we can see evidence of these in the Universe today.

The Planck Space Telescope was able to pick up echos of BAOs from the early Universe and scientists have been able to translate them into audible frequencies, in the example below. The hum is composed of a low tone with higher overtones. The whoosing sound that can be heard is an artefact of the processing used to make the sound file.

Sounds of the early Universe

Then, at about the age of 379,000 years old, the Universe cooled enough for protons and electrons to pair up and form the first neutral hydrogen atoms. The plasma disappeared, leaving the Universe suddenly and dramatically transparent to light. At the same moment, the battle between radiation and gravitation ended, BAOs ceased, and the Universe went silent.

The blast of light energy that now spread through the Universe was so powerful that it still jangles radio telescopes and tantalises physicists more than 13 billion years later as a signal known as cosmic microwave background radiation. The "CMB" is the oldest and most detailed visual record of the early Universe. Here too scientists can see a "fossil record" of the Universe's first sounds.

"We see them imprinted on the cosmic microwave background, and also in the large-scale structure of the Universe," says Santos, who is part of a new international radio telescopy project analysing modern echoes of that long-silenced song. "Their signature is found in a small excess in the number of pairs of galaxies separated by a fixed scale of 150 Megaparsecs — around 500 million light years."

You might also like:

The mystery of our expanding Universe

Why time doesn't flow backwards

How supermassive black holes got so big

BAO signatures not only hint at what the early Universe sounded like, but also serve as a ruler for measuring the effects of yet another invisible phenomenon: dark energy.

Dark energy causes the Universe to expand. Its effects are everywhere, yet its nature is unknown. Studying the scale of BAO signatures at different distances from Earth tells a story about how dark energy's effects have changed over the history of the Universe.

"We call it a standard ruler," says Santos. "We have this fixed scale. We can know by how it appears to vary how the Universe was evolving through time."

The ripples created in the primordial plasma led to matter clumping together in ways that can still be seen in the way galaxies and stars are clustered (Credit: Nasa Goddard)

Hydrogen atoms release radiation with a 21-centimetre wavelength – invisible to human eyes, but detectable via radio telescope. This radiation from more distant clouds of hydrogen gets stretched by dark energy, increasing its observed wavelength here on Earth. The further it has travelled, the more stretched out it is.

"You choose a frequency for your radio telescope according to the epoch of the Universe that you want to measure," says Santos. Bingo is designed to map hydrogen distribution between one billion and four billion light years away – relatively close on the cosmic scale of space and time.

Bingo's two towering parabolic mirrors reflect this primordial radiation onto an array of 50 flared wave detectors known as "horns". The telescope's main moving part is the planet it rests on. The rotating Earth moves the telescope beneath the stars, scanning a strip of sky 15 degrees by 200 degrees.

Using subtle statistical calculations, Santos will analyse its data to locate millions of galaxies, examine their relative distances from one another, and dig deeper into how dark energy affected BAO patterns during that era.

"Bingo will look to the late Universe when dark energy already dominates the expansion. It's very complementary to other experiments," she says.

Many of those other experiments are already planned or underway.

"Hydrogen intensity mapping can in principle measure anything in the Universe between present day and up to the CMB. That is a huge volume to explore," says Cynthia Chiang, a professor of physics who studies hydrogen density at McGill University in Montreal, Canada. "Bingo and other similar experiments look for the gas that lives inside galaxies. It is a tracer for where the matter is."

While instruments attuned to relatively close regions interest Chiang, she also craves answers about the rest of cosmic history.

"I take a very greedy approach to this," she says with a laugh. "I'm putting together an experiment that is tuned to frequencies that correspond to the 'Dark Ages'. That's the period immediately following the formation of the microwave background. We have never accessed any cosmology from this time period because it's very, very hard."

Between 250 and 350 million years elapsed between the "surface of last scattering" when the baryonic plasma gave way to the CMB, and the "cosmic dawn" when the first starlight shone out. BAOs left clouds of hydrogen clumped in wispy striations, liked an ebbing tide leaving ripples behind in the sand.

Before Chiang can access the 21-centimetre radiation from this era, she needs first to design experiments to filter out more recent signals from our own galaxy that could mask older data.

"This first experiment is not yet going to get at cosmology," she says. "The goal is to map the Milky Way emissions at these frequencies at a very high resolution so that we know what the sky looks like as a first pass. Then, hopefully, we can subtract that off and get to the cosmology.

"As the name suggests, in the Dark Ages, the Universe was a very dark and boring place. The signal you get then is almost a uniform 21-centimetre emission from this wall of hydrogen. But there are faint fluctuations in the brightness that correspond to the over-densities and under-densities. You get tiny cold and hot spots."

She says the CMB is like a still photograph capturing (in amazing detail) a pivotal moment in cosmological evolution. Mapping hydrogen density in the Dark Ages, though, would capture the hundreds of millions of years that immediately followed.

"It's a three-dimensional volume you can probe," says Chiang. "If you can measure the same sort of information as the CMB but reflected in hydrogen instead, you get tremendously more information, and you can potentially constrain cosmological parameters even more. If we get there, that would be amazing. But that's a very, very long road."

Did we get the age of the Universe drastically wrong?

Chiang's planned experiments, alongside the Bingo telescope, add to a growing array of innovative observational instruments laying bare the history of BAOs, the large-scale structure of the Universe, and the invisible dark energy that drives galaxies apart.

"When we measure the sky, we measure everything," says Santos. "CMB, neutral hydrogen, galaxy point-sources, all this kind of stuff. We must be able to recognise what's a cosmological signal and what is everything else."

Santos also hopes BAOs will reveal even more about the Universe's past, piercing the 379,000-year-thick wall of plasma and providing data on the previous fraction of a second – the Universe's "inflationary epoch", during which most cosmologists think space was expanding at a rate faster than the speed of light.

Cosmological inflation is a widely trusted theory of how our Universe got from its tiny, hot, dense, original state to the cosmos we see today. The theory has gone through many incarnations, variations, and simulations. It makes many robust predictions that have been tested and verified, yet there is no direct evidence for it.

"Many, many inflationary theories have been already discarded by our observations," says Santos. "With the measurements we want to see, we can determine which theories agree best with that measurement and go from there."

Baryon acoustic oscillations only existed for a few hundred thousand years, but they helped create — and are helping scientists tell — the story of the invisible Universe from its first moment to its last.

#The weird hum coming from the start of the Universe #space #noise #space noise #cosmological inflation

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vyzz-undercover · 2 months ago

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the voices have made this happen

[cato/f!ambassador]

(1) (2) (3) (4) (5)

(5,900ish words) (OUUGHHHHH)

CONTENT WARNINGS:

•slight dubcon

•hints of size kink [obligatory]

•vaginal fingering

•oral [f receiving]

•mild possessive behaviour

•the consequences of ignoring important medical devices

•mentions of (hypothetical) torture

•tumblrs recurringly cancerous formatting

———————————————————————————————————

im back on my bullshit after having to do overnights so as payment to the dark gods of whoring and degeneracy i humbly offer this taglist of sweet darling who've indulged my insanity: @the-raven-lady, @gallifreyianrosearkytiorsusan, @bispecsual, @lemon-russ, @kit-williams, @passionofthesith, @egrets-not-regrets, @moodymisty, @sinistermojo, @justeverythingnothingelse, @pluvio-tea, @thevoidscreams, @beckyninja, @yestheantichrist!!! if you wanna be tagged (or not) in the next let me know!!! also it may take me longer to do a part four to this namely because ive got more wageslaving ahead of me soon but alas i'll definitely have rowboat girlyman catch em. also maybe give cato some top. myehehehehe,,, AND THANK YOU FOR READING AS USUAL ILY ALL!!! :3

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Cato is just about leaving.

After having spent the better part of an hour discussing the predicted destruction pathway of a hive-fleet on the system's rim with his Father; it sends his balls into his throat when you nearly run into him in the chamber's huge archway.

It only takes a fraction of a second to catalogue your presence.

You're wearing the same utilitarian blue robe as you had been last week again.

Last week, when he'd been pounding you insensible on a lounge in the library—Cato promptly quashes the insidious memory, smothering down any sort of reaction. But there is a change in comparison to the dizzying reminder: there's a new addition to the reoccurring outfit.

You've brought a navy, high-collared turtleneck into the mix, layered below your lapels.

So, the efforts of his mouth hadn't gone unheeded, then.

Throne, if he's not smug, he's got no bloody clue what he is.

Cato steps aside and turns to allow you entrance first before his exit.

"Commander Sicarius," you lilt with a soft voice and a small downward tip of your chin, all while holding his gaze.

He's transfixed periodically at the honeyed sort of warmth in your eyes.

Despite himself, he lingers and greets you with a slow, "Lady Ambassador."

The left side of his mouth twitches upward in a half-aborted smirk that he quickly tries to mask as a stern, frown-nod combination.

You break the staring match and Cato's confident he's salvaged his slip-up without detection.

Or not—because oh, fuck—if he doesn't feel the burning focus of a Primarch's eyes boring a hole into the side of his head like a brand.

It only lasts an instant, but the second is an eternity to him.

Of course, you're oblivious to this subtle exchange—and promptly trot past him to his Father's vast desk.

"My Lord Primarch," you say with a curt little bow; and then Guilliman's attention is solely on you, his favourite little pet project. "I read the data-drives you instructed from the preceding article logging. I've arranged them back to the most recent mark counts."

You're looking for an empty spot to lay them on his table, but with all the meticulously arranged stacks, it's none too easy to find one.

"Perfect," the Primarch breaths, "Just on the side there is fine, don't worry."

Obligingly, you lay them atop a small mountain of paperwork.

"Do you need anything else of me, my Lord?" You chirp brightly, the tone of your voice so very painfully sweet—Cato is nearly overwhelmed fighting a pitched battle against the urge to run over, pick you up and shake you around suddenly.

Guilliman chuckles, waving one massive hand about vaguely, "You've done more than enough for me today, why don't we leave it at that for now, hm? Go on."

"Of course; thank you, and have a good evening, my Lord," You say, bow once more, and turn on your heel from the Primarch, and—and smile at Cato as you walk back towards the exit. That's—that's the first time you've smiled at him. His twin hearts lurch, slamming forward against the inside of his fused chest cavity. It's perfect abominable. You rotten temptress, he's—he's going to rectify that audacity later. Or now, if you're... possibly heading the same direction he is. Which is whatever direction you're going, purely by chance.

It's merely coincidence, he swears.

He's certainly not planning on hounding after you like a dog tailing a bitch in heat.

He's certainly not going to drag you into a side room the second he's sure no-one with a credible opinion's around.

He's certainly not going to indulge in anything heretical, like bending you bare over his knee for daring to taunt him.

Cato makes as if to fall in step behind you as you pass the threshold before him, but is quickly halted by his Father's curt, "I do not believe you have been dismissed, Cato."

He's never been subjected to such sinking dread quite so nonchalantly.

"Approach."

Cato complies stuffily, sparing a glance at your figure disappearing down the corridor before acquiescing. He's practically dragging his ceramite boots across the intricate rugs as he nears the Primarch's seated but colossal form.

Guilliman isn't looking at him, having had returned to notating a miscellaneous form.

The scritch-scratch of his gene-sire's preferred, yet archaic method of manually writing on the parchment is like someone grating a plate with a fork to his ears right now.

"You've gotten over your petty grievances regarding the Ambassador at last, I take it?" Guilliman asks, without looking up.

It is not Cato's duty to like or dislike. Nor is it to be biased without reason—his opinions are to be intellectual, not emotional. His duty is to assess, analyse and provide feedback, so that his Primarch can take it into account when making rulings and decisions.

Cato swallows around the proverbial hunk of drywall lodged in his throat and answers, "She has proven herself... useful, yes, sire."

Guilliman finally meets his eyes but says nothing for a short while. There's dark bags under his Primarch's eyes, and the deep, stern crease permanently between his dark blonde brows is a slight bit harsher, but the only thing Cato can parse out of the expression's intent is a vague sense of knowing. Because, insofar, he's thought himself quite adept at reading his Primarch; and rather well versed in deciphering the intricacies of his moods.

And right now, he feels like he's being read like an open manuscript.

The daunting prospect Cato's caught sinks it's teeth in his gullet. It's impossible, he's not left any room for suspicion, he's covered his tracks—there's no logical reason why he should be getting raked with such a look.

His gene-sire isn't a psyker nor omniscient, just impossibly intelligent—and so absurdly good at the mathematics of plotting and planning that it only appears superficially as if he is all-seeing. He can't possibly know what Cato has been doing—or rather, who he's been doing.

"It's about time," his Father hums abruptly, suddenly disinterested. "Now you're dismissed."

Cato nods, turns on his boot heel, and nigh bolts marches out the room. His proverbial tail definitely not between his legs.

The hall outside Guilliman's apartments is a central domed area that functions as a meeting area, where people go to one of six looming hallways. It's the bottom of a series of levels; and above, three echelons encircled by arcades and balustrades, framed on the exterior by engaged columns.

But the structure itself is immense and ancient, even by Imperial standards. One of the few still-original, unaltered parts of the great Gloriana-class warship's innards. It is doused in long swathes of red carpet and great standards of Magcraggian note, alongside glorious, heroic frescoes depicting Legiones Astartes in their thousands, crusading across the heavens with the Emperor their head.

Cato keeps his head down as he passes them, uneasy with guilt. Feeling as if their lenses are following him—intent on venturing into the lower layers to brood.

Several Astartes are hovering about amongst the personnel and serfs. The baselines look up at him in awe, and his Brothers nod in respect, but he pays them all no mind.

The furthest corridor beckons him, and so he goes; down the complex system of broad walks with high, barrel vault ceilings, mazing through the vessel's higher clearance reaches like arteries through a body.

Cato is seething, and self-admittedly itching to take a howler of a swing at the next thing that speaks to him.

He cuts down the southern channel and sees one of his subordinate Victrix Guard lingering in the middle of a groin vault intersection.

The younger Astartes is about to continue straight, yet he pauses.

Brother Marcellus meets Cato's eyes for a second, clearly notes his Commander's absolutely stinking mood from a hundred meters off; nods, swallows, takes a step backward—and changes direction to go left rather than pass him.

Cato's too pissed to even linger on the strangeness of the action.

Still, he doesn't rightly blame him.

Cato strides on, back straight, chin up—the red shawl pinned beneath his pauldrons swirling behind him.

His thoughts are eating at him the whole while.

He's sure his Primarch is just trying to innocently divine his sudden change of mind regarding you. There's no way his Father's aware of why. And yet, guilt is a big black wolf nipping at his ankles, making him hasten; and unease clouds about his heart. He's mortified, for lack of a better word.

The full implications of the situation are too enormous to be faced all at once; so he picks the smallest, most banal facet he can think of.

That being, you.

You, who he'll never see again if his Primarch finds out.

You, who's practically damned him without knowing it.

You, who he's now valiantly trying not to imagine in a hundred different circumstances where he gets away with it all. Each one more heretical than the last—it's like it was before he'd managed a hand on you: his body giving in to suffocating delusions, sleepless in his cot; lapping at whatever scant, lust-soaked morsels his mind offers up.

One of his favourites remains you scantily clad beneath a moonlit night sky, on the parapet of his ancestral fortress on the coastal edge of Perusia.

He likes to fantasise you like it there.

He suspects you would.

He knows just about all there is to know about you on paper, and wonders if you know much of Talassar. Or if you've read about Castra Tanagra. He assumes Guilliman would share the tale of that famed old battle with you as a part of your readings.

Each impossible reverie is a new shiny nail in his coffin, or dreadnaut—it depends where and how he dies, and if there's anything scrape up of him when he eventually goes down in a blaze of glory and duty, and honour.

If his Primarch catches him, there's going to be none of that.

He'll be struck from living record, like Titus had been. Cato would be lucky to get a little plaque in the deepest pits of the Fortress of Hera. Reduced to a whispered memory of his achievements passed solemnly between Captains, followed up with words of disappointment. Of waste. Until his memory dies with them and his deeds fade into obscurity, lost to any new brothers.

The fate that awaits you would somehow be worse. Cato was always going to die in war, as was his right—but you—you were not fashioned for such things. Yes, Guilliman enjoys you, but that fact won't save you. Just like it won't save Cato for all his usefulness. You'd be tried as a heretic, as a source of corruption upon the Legiones, and you'd be made to suffer; because torture ever comes before execution. You're so very soft weak in so very many ways. Your life lived in a gilded cage, without pain nor discomfort that extends further than grating professional grievances—he doesn't want to imagine the sound of you screaming, but he does.

He cannot stand the thought.

The sudden urge to barricade you in his chambers for permanent safe keeping is all-consuming.

It's suddenly all he can think about.

He has to find you.

The amount of serfs passing and parting to allow his passage thin out to nothing.

Even from the sterile confines of one of the many winding hallways, Cato abruptly swears he can hear the echoed rush of sandals—your sandals—reverberating off the floor.

He hadn't notice you following behind immediately because, damn it, he's spiralling thinking.

He chances a confrontation, and rounds about-face.

You stand there in the middle of the empty hallway like you've got a bolter aimed at you, frozen.

"Come here," he says, clipped.

You do not.

"Come here."

Again, no compliance.

"Do you pride yourself on being a idiot?" His voice is scathing now, taking a heavy step into your space and being met by you staying stock stiff, still. "Do you have any idea what that stunt of yours earlier might incur?"

"What?" You blink, finally animating. "I didn't do anything—"

"You know what you did," he hisses, accusatory. "You're hollow between the ears, but you're not blind."

Lips pursing tightly in mental deliberation, you make a fey noise of annoyance as a little frown graces your features, apparently not deigning to offer a comment back.

"Do you not understand that... this," he gesticulates between you both and his voice falls to a whisper. "This... is not common allowance?"

"It's not?"

Are you being intentionally dense at this point, or is it just second nature?

Cato raises a hand to knead the crease between his brows, "No."

"That explains a lot, actually," you say, seemingly without any real comprehension on the gravity of the matter. "I couldn't find any notes or references on it."

He's genuinely stunned, "Is that what you were doing when—"

"When I was rudely interrupted," you cut in, the comment is nigh a spat insult.

Cato isn't sure what to say to that sudden display of spine, and grumbles.

He surmises the optimal action is complete disregard.

Therefore, he has no problem turning on the heel of his sabatons and starting his pace on again.

"So... this isn't normal by Astartes standards?"

He's taken aback at your abrupt want for conversation after all that. Namely because it's atypical. You never attempted small talk with him. You never do anything but scurry off when he's accosted you for you flagrant overstepping—wait.

He feels as if the paradigm between you both has shifted again since the last time for some reason. More than last time, actually. More than you just simply having the audacity to backtalk him.

It's like some symptom of a deeper sickness rising to the surface.

It makes him unreasonably curious suspicious.

He wants to see just how much ground you'll give, so he plays along and answers, "Not as far as I am aware, no."

You hum, and immediately are at it again, posturing, "Surely you have heard of cases of it happening?"

"I have not," Cato says, and you hum in consideration.

You're satisfied at that information for a brief while, but then he remembers you cannot shut your mouth for more than five minutes, and purses his lips. He's already tiring of your incessant questioning.

"But you'd done it before?"

And that's just great.

You've expertly found an exposed nerve.

More kindling on the bonfire of him having an aneurysm before the cycle's end.

Cato can feel the hint of pressure behind his eyes as he begins increasing his walking speed. "I don't think that is a relevant question."

You haste to stay in step, "It definitely is."

"You ought to learn a civil fucking tongue when you're addressing me, woman," he bites out, nose crinkling into a sneer.

Unperturbed by his short-tempered comment, another thoughtful little 'hmm' slips out of you.

"So, to conclude... you where as inexperienced as I was at the start, and all those gloating insults back then were just projection?" You suddenly blurt out at rather impressive speed, like a politician possessed—before finishing with, "Sorry, 'all those gloating insults back then were just projection,' Commander Sicarius."

Cato grits his teeth and feels his eye twitch.

He stops, turns to look over his pauldron, and stares bloody murder.

He can't even imagine the idiocy in your brain that gave you the imprimatur to say that aloud.

But Throne, the sly little glint in your pretty eyes suddenly has his face thudding with heat.

Then you smile at him for the second time ever.

Cato bites back the urge to ogle you dumbly, and actually feels himself thicken in his body-glove in real time, because oh, fuck—his hind brain practically pelts him across the jaw with the mental pict of that sweet mouth lathing up the side of his cock.

Mentally unseated for a moment, his brows furrow; and he quickly turns away, applying himself entirely to the task of trudging down the stagings.

The silence is a breath of fresh air.

Even if he can still hear your laboured breathing a few steps back him from him. You're straining to keep up with his pace, and it's an excellent punishment for you. His heavy sabatons clank-clank-clank on the steel decking, and your little shoes practically pitter-patter in contrast. It's a syncopated rhythm that he's absentmindedly trying to match—and when he lingers for a step he manages to even the beat out.

He hangs a left, and scales the wide stairs to the open intersection platform above two at a time; trying not to snort amusedly at the little groan you let out as you hurry up them behind him, heaving.

Cato realises abruptly that you're actually, really, seriously following him—and pretending you're not.

He makes a right at the top and then waits for you to fall in step.

And, pointedly, he then turns and doubles back around.

You stand there stupefied for a moment, before grumbling softly and continuing down the thoroughfare without him.

If his observation skills hold any weight, he heads straight into the nearest open room and waits for you to follow.

He doesn't activate the locking mechanism on the other side on purpose when he strides in, and lets the sliding door close behind him.

This particular room is forgettable in its ubiquitousness, though unusual. He has no idea of it's actual intended purpose. It's fitted with screens and database terminals as if it's for debriefing purposes, but he has no real way of confirming. What he can catalogue is that there's wraparound surfaces littered with candles. A few strips of harsh lighting and scant furniture—a tallish counter and a few long benches. They're thankfully Astartes sized.

Which means he can sit down and pray for you to walk right into the metaphorical snare he's just laid.

Not a minute later, the door's sliding mechanism triggers and you scurry through—only to promptly go stiff.

You stare at him like a rat he's just found by lifting a crate.

The mechanism shuts automatically behind you and it apparently spooks you enough to jump a little.

"You're disgustingly predictable," he harrumphs, unimpressed.

A flush rises to your face as you scowl, "You're disgustingly predictable," you shoot back, echoing his words.

Of course, that audacity of yours leads to a short stalemate.

He huffs out a sigh as he concedes out of sheer frustration and says, "Three-seven-five-eight-eight-two-nine-one."

You blink dumbly at him, "...what?"

"It's my locking code," he growls, and Throne, you must be acting stupid just to grate him; because there's no way your brain is so smooth as to not connect the dots. "It's for the door, moron."

A soft 'ohh' leaves you as you turn and step aside to the key pad fixed into the frame.

"Three-seven-five-eight-eight-two-nine-one," he's agonisingly forced to say once again.

"Three-nine-five-eight-eight-two-seven-one..." you mumble to yourself.

Cato hears an angry beep and suddenly wants to smash his head into a wall repeatedly.

Grinding his molars, he snarls, "Three-seven-five-eight-eight-two-nine-one," and then adds, "If I have to repeat that one more time, I'm going to throw you out of the nearest airlock."

And it seems the threat of violence works wonders, because you don't bungle the input this time.

Cato sighs, exasperated, and leans back against the lip of the table behind the bench.

He ought to start carrying around a correctional stun rod. Just for whenever you annoy him. If it's good enough for a Neophyte to suffer, it's good enough for you, he supposes.

Or it'll send you into a seizing fit.

He's not to sure of the maximum voltage a baseline can take without their singular, puny little heart giving out.

One disciplinary option scratched out, then.

But he can think of many, many more to make a model Ambassador out of you. The wonders of carefully applied violence are plentiful. A little roughing up never hurts, or at least, not for long. And fuck, do you need some lessons on proper manners. He could have you smacked into shape like a show pony in no time—even if it'd be more like teaching a grox to trot lateral movements. Then again, he also believes if he stuck a frag far enough up a Carnifex's ass, he could probably get it to play Regicide.

And then pointedly, he starts thinking about your ass.

Cato is so utterly lost on the tangent of hypotheticals that he's flabbergasted when a small mouth lands on his own.

He hadn't even been paying attention.

He hadn't even noticed you'd neared.

It feels like the breath has been knocked out him at the sheer unexpectedness of it.

The kiss is hasty, your eyes scrunched shut and cheeks flushed, scowling with focus.

All the while, his mind reels because Throne, the contact of his lips to yours doesn't really feel particularly profound aside from how soft your skin is—but the intention of it is the real reward.

Cato's genuinely infuriated when you pull away.

You blink owlishly at him, giving him a cautious look like you're trying to gauge his reaction.

There are a thousand things he wants to ask, to say, but the foremost among them is but one.

"Again," he huffs, lessening the distance between you just enough to invite you back.

And he thinks that perhaps he’s abusing his station over you, but when you tentatively find a hold on his gorget to steady yourself to give him another kiss—those thoughts are all but erased from his mind. It's a curious weight off his shoulders to have you initiate and to show you want him in return, especially since it's as new to you as it is for him.

Nonetheless, he can't even imagine finding a reason to stop you, so he starts blindly mouthing; trying to coordinate around the fact he's so much larger than you.

The angle is difficult, but he's willing to follow your lead. Your body is even more fragile when he's in full armour. The risk of actually hurting you is realer than ever, but he can't help the desire to wrap an gauntlet around your waist and pull you closer to him. Thankfully, you let him when he urges you to, trembling hands flitting across his chestplate like you're unsure of what, exactly, you should be holding—and he catches the tiny line between your brows smoothing out as you risk a peek. Only for you to yelp, nervously wrenching yourself back in flustered surprise upon meeting his unwavering stare.

It's as if you expected something else.

He senses he's made a mistake of some kind.

Then he remembers from the motion-picts he's not supposed to keep glaring at you when kissing.

Regardless, he studies your face, memorising the lingering want still clearly there like his life depends on it.

He pulls you in and kisses you again, just because he can, this time brief and chaste. And then he goes for a third, fourth—fifth, each time slightly longer, until finally he rears back; and when he does you push up on your toes just a little, trying to chase him, but lose the nerve; although to Cato the reason for your faltering is, frankly, irrelevant. Because just like him, you lack the practical capacity to really know what next step you should take. Still, you look down at his armour, as if there's a latch to pull that magically undoes all his wargear.

He knows he's not going to get himself out of his armour in any reasonable way or amount of time.

There's no way he's getting the satisfaction of having you on him right now—but he still wants to keep you near.

He thinks he hears you ask for something, but he's too distracted to catch it in time.

"What?" Cato scowls, "What do you want now?"

It's clear you've been struck by your own embarrassment, strung up somewhere between shy and wanton, "I.. uh..."

"Spit it out," he rumbles.

You wince, hesitant as you mumble, "You, uh... i-in me."

Cato's brain skids to a halt. And it's the gall of that request alone that has him sweeping you up off the ground and spinning you around to sit in his lap.

It's obvious you're overwhelmed at being held to the formidably larger size of himself in full-plate. But as usual, you're yet to actively complain. Using his vambrace as a leg-bar to scoop under your thighs, he folds you in his grasp—your knees pressed to your chest as you're tucked back against his pauldron and chestplate.

The angle forces the hems of your robe aside, and he can see the underside curve of your ass; along with the plump mound of your vulva under the white of your small-clothes.

Cato's suddenly offended by their existence. You didn't wear any last time, so why now? The irritation of there being one more thing between you and him is enough justification to yank at them, tearing them loose—before throwing them aside.

You grumble sourly, which he chooses to ignore.

The palm of his gauntlet smooths across your hip, and you make a small huff as you shiver, goose-bumps suddenly covering your exposed flesh.

Cato lets the pads graze closer and closer to your sex, content to watch you impatiently glare at his armoured fingers from between the gap of your thighs.

With little preamble, he's stuffing his middle in. You're already so wet it's practically a cake-walk. Your cunt swallows down each articulating segment of his armoured finger down to the knuckle. The fact he's going to have to personally scrub your slick out from between the joints, instead of a lowly serf, is infinitely worth the shrill whine he receives as tribute.

"Would that my wargear had a zipper," he breathes, and fuck, he grins behind the obscurity of his gorget at the mournful mewl that remark earns. "I'd have you on your knees sucking for all the cunted trouble you've caused me."

You're making a warp-awful attempt at keeping yourself together, high-strung as you evidently are. Little more than a minute of him pumping his finger in and out of you has you red-faced and panting. All it takes to get those heavy breaths of yours to change into proper whines is his large thumb-pad adjusting to rest on your clit, applying pressure. You jerk, reflexively trying to buck into every motion. Fighting and failing to withhold the stuffy little moans escaping you—trying to stave off the inevitable by scrambling at the thigh plating of his power armour with one hand and tugging at his couter with the other.

Some part of Cato wants to stop solely out of spite for you being so grating earlier, or some other stupid mercurial justification of his; but instead, he simply continues, letting you squirm on his fingers.

And squirm you do.

It's clear to him the tide of it all is becoming too much for you to resist. Your sandal'd feet kick out where he's got your legs secured, joining in on the struggling as it begins anew when his thumb starts circling. It's a good sign, so he adds his pointer into you to bolster the stretch, curling in; before letting his fingers fan out inside you, stretching rather than stabbing. Your hips try to stutter forward in time with the quick thrusting of his digits, broken whimpers resonating off the room's walls. He promptly stuffs down to the knuckle and curls them again—and you all but bleat his surname as you're dragged into a fast and apparently exhausting orgasm. Just knowing he's you got you beat has his erection ache where it's trapped under the suiting and plating of his navel.

Cato can't feel you clenching through all the layers separating his skin from yours, but he knows from experience that you're seizing in fits internally—tight little cunt trying to milk a load out of an Astartes cock that should've been stuffed in you.

Just to allow himself one last bit of smugness, he scissors his fingers; giving a final swirl for good measure.

The shivered sob is worth every possible future disciplinary action he'll receive.

He pulls his gauntlet away slowly, and the wet shlick of it leaving you is almost amusingly alike pulling a blade from sinew. It's a degenerate comparison, he knows, but it's true.

Nonetheless, he splays out his hand and swallows dryly, eyeing the sticky, clear liquid webbing out and thinning between each ridge of his gauntlet'd digits.

Suddenly focused entirely on the fluid on his fingers, he pulls his vambrace barring under your knees up away. Now limp, and without the support, you slide off his lap and onto the floor in a slow slump.

"Nn-ngh," You groan weakly, face-down, legs still juddering a little.

Seeing as you're preoccupied, Cato doesn't even dignify the concept of hesitation, and promptly jams his fingers in his mouth—lathing the aftermath of your orgasm from them. And Throne, the taste of your hormones make him groan. He's absolutely stunned, unsure of how to act. He's so fucking stupid, why didn't he do this earlier? He's practically drugged by the omophagic aftereffect—getting off on your second hand bliss. Some sort of fey feedback loop in his brain catalysing his next decision solely on instinct.

He clambers to the floor and gets to his knees guards, securing a mitt on your bared thigh to roll you onto your back.

Apparently boneless with afterglow, you're easy to manhandle.

You barely have the strength to do much more than crane your head up at him and whine as he arranges your thighs apart, settling on his front between them with a warp-awful clank; before lifting your legs up to rest onto either lip of his gorget.

You try to scud back on your ass suddenly, but are quickly halted when he holds you fast by the hip.

He raises a confused brow.

"I-Isn't—" you start, still gathering the scraps of your brain together so soon post-orgasm, "Isn't y-your saliva acid?"

Cato suddenly wants to cuff you on the ear, "Who the hell told you that?"

"M-Master Calgar," you mumble.

Oh, of course, the gossiping hen.

He's going to have words with the Lord Defender of Greater Ultramar the next time they meet—words like 'for fuck sakes, stop scaring the woman he's trying to eat out with talk of Betcher's gland, Marneus,' come to mind, but then Cato realises that doesn't sound like he's not fucking you, so he quickly settles on: 'stop dignifying the Ambassador's hundred-and-one insane questions.'

"Not Ultramarines," Cato manages not to snarl, "It's a vestigial organ in most of us."

Your voice is shaky as you parrot, "Most of us?"

"Yes," He grunts, and promptly buries his face in your cunt.

The disproportion in size is painfully apparent when he realises his whole damned tongue is able to drag a stripe up the entire splay of you with minimal effort.

The pitched gasp he wins out of you is pure sin, and he's on the brink of swooning; but then you're running your trap again.

"Please, d-don't tell me you're one that can spit acid—" you manage to warble, seemingly still stuck on the topic.

Cato sighs as he's forced to pull away from your vulva, "I think you're forgetting I had my tongue on your tonsils in the library."

"Th-that's different," you stammer. "That's not as sensitive."

A long, unimpressed deadpan paints itself on his face.

"So," he starts with a bated hiss, "And let me be perfectly clear in this—you believe your vagina is more susceptible to burns than your mouth?"

Your face transforms into a strange mix of embarrassed and angry.

"I didn't say that—"

"Yes, you did," Cato grumbles.

"Did not," you huff.

"You—you just fucking did," he snaps, frustrated enough that he can feel one of the veins at his temple bulge. "The implication is obvious, you insufferable little whore."

You snort, but stay silent.

The argument appears, for all intents and purposes, to be finished.

"Did not," you say abruptly once more, pouting.

Cato's eyes roll back in his skull as he grits his teeth.

"Throne of Terra, if you don't drop the subject, acid in your cunt will be the least of your worries," he all but snarls, and that apparently quietens you enough that he can get back to lapping at you—the flat of his tongue running over your clit and earning a jolt.

He wraps his lips around the pink little nub and sucks. And that's all it apparently takes to make up for his amateur career in the practice.

You siphon down a sharp breath and let out a garbled cry, hips canting forward into his mouth—to which he obligingly stuffs his tongue into your slick entrance.

There's a satisfaction well beyond simple pleasure that swamps him at the way your thighs shake either side of his head. His own breath is hot about him, stuffy and dizzying; and the skin pressed against his cheeks is warm and smooth.

You're panting when he goes back to lapping over your clit, perching yourself up on a bent elbow and reaching out a hand.

Your fingers card through the messed brown hair atop his head. And he stiffens without realising—but he realises something: like this, the touch is ecstasy—pure, golden ecstasy. Every bit of higher thought in his head evaporates when you stroke him again.

A long, rumbling subvocal moan tears from him.

The infrasound vibration makes you buck weakly into his mouth again, teary eyed afore him as he adjusts his grip on you and crawls closer.

He's suddenly acutely aware that in this new, much more prone position, he's able to grind his body armour into his groin guard pressed on the floor. And as soon as the action bears results—namely a scorching burr of pleasure racing up his spine—he's deadset on rutting against the ground like a slavering beast.

He's frotting himself at a pace so rabid it'd be cruel to subject your cunt to. It's brutal, and the harsh scraping sound of plasteel on steel only further proves that. It's just frantic lust—he's desperate.

It's complete insanity how close to finishing he is so quickly.

Not as close as you, though.

He can feel how your legs jump with each pass of his tongue; and then you're unraveling in front of his very eyes.

"I-I can't—I can't, S-Sicarius, I-I—" You ramble, dazed, trying to get away as he works you right through it, sobbing and oversensitive while he's rutting himself closer and closer to his own end.

It all comes to a head when your fingers dig into his hair, tugging—and his brain is overrun with static. A drawn out groan scathes from his maw as any sense of rhythm scatters like light through a prism. For a fraction of a second, the pleasure is serene.

Then it's abject agony, he feels—he feels like Roboute Guilliman himself has just taken a running start and kicked him in the balls.

"F-Fuck–ing—gh—" he chokes, vision swimming, straining against the tide of the torment. His back arches up, and he curls inward on himself; white-hot pain clocking his nervous system into overdrive. Every muscle in his abdomen is doused in acid. He's tolerated being shot, stabbed, burnt without so much as blinking—but this is an entirely new and entirely different sort of wound. It's like he's pissing promethium. It's—it's the catheter, he realises. He'd forgotten about the bloody catheter jammed up his cock.

Through the searing ordeal, he manages to force his armour's facilities to finally abide his impulses and dose him with a pain dampener.

And then everything's fine.

He opens eyes he wasn't aware he'd closed and finds your face has suddenly gotten far closer to his.

"S-Sicarius?" You stammer, and there's an honest panic in your voice. "Sicarius, p-please, please—a-are you okay?"

He realises he's on his back, and you're sitting beside him, half draped on his chestplate, frantically trying to figure out what's wrong with him to no avail.

You've leaned in so close he can feel your rushed breathing.

"I'm fine," Cato groans, and you sputter out a sigh.

"I-I don't know what happened, I-I—" you're still wildly confused and raving, and he inhales deeply; only to be greeted by the sour animal stink of fear practically dripping from you.

Cato rolls his tongue around inside his mouth and cringes knowingly at the foaming side-effect of the chem he'd self-administered, the acrid taste mixed with your slick is certainly not an ideal cocktail.

The sincerity of concern behind your reaction is baffling. He's not made of glass, for fuck sakes—and he's a bit pissy about the fact you'd actually fallen victim to the idea of him suffering some grievous injury so easily. But he supposes where there's a will of baseline overreaction, there's a way.

"You're acting like a child, woman. Pull yourself together," he sighs hoarsely, hoping the comment jars you out of your hysteria—or at the very least scares you off.

It does exactly neither, and you sidle in closer and rest your cheek on his jaw.

It’s an action so overwhelmingly horribly affectionate that it would’ve been a crime to not press into it with a lean of his head. Or, at least, that's the half-assed justification he tells himself.

Because he's loving enduring your attention, not seeking it; and therefore only humouring you when he lifts a hand and settles the wide splay of it on your flank as a comfort.

He shouldn't be, but he is.

#warhammer 40k x reader #warhammer 40k #reader insert #warhammer fanfic #cato sicarius #space marine x reader #cato sicarius x reader #writing #ultramarines #cato 'im going to kill the next person i fucking see' sicarius #*squeaky noise*#ambassador 'omg hiiiii'#FUCKKK #anyways #roboute guilliman #i am so fucking sorry you have to deal with this shit baby girl #also LMFAO I DO THINK CALGAR LOOOOVES A GOOD BITCHING SESSION

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