Are tyranids even biologically possible?

It doesn't matter if meat is 'rotting' because all that means is that it's being eaten by maggots and microbes. Biomass is rather hard to lose.

The main difficulties of tyranids would be travelling between planets and being able to quickly genemod organisms. They're like army ants with entire kingdoms of life at their disposal.

>could they actually devour more than they lose given that they often face heavy resistance from the beings they're about to consume?

Short of losing huge amounts of mass in space and being completely wiped out on the ground, it's as plausible as anything in the setting.

If they win, even if there's very few on the ground they may be able to spore or breed or whatever it is that they do until they recreate a hive ship, and then become mobile again. Anything left on the planet - dead or alive - would just be consumed (as many times as necessary) as fuel/building material. In space, it's possible you could atomise the entire local fleet to the point that the mass would be "lost", inaccessible to follow-up fleets, but we should probably assume some kind of filter-feeding capacity for the larger vessels, even if it's by proxy and they simply gather space crap on their exteriors and smaller creatures eat it.

The questions about energy density and usefulness of materiel are hard to answer, because we know for example they're described as stripping worlds back to barren rock - all oceans (of water or whatever), all soil, presumably sand - which implies either what's below the rock (in many cases) in the molten interior of a planet is unusable to them in the timeframes they're prepared to expend on consumption, or that it's unusable to vanguard fleets but something hitherto unseen by any living non-Tyranid will come along and gobble up these rocks at its leisure, or that the energy required to break down an entire planetary structure is indeed not worth the materiel gained from doing so. This last point seems unlikely, as we know from at least one instance that a hive ship will swallow a small moon whole, suggesting they can reduce rock to its constituent elements and re-use those relatively easily, which in turn suggests the unseen world-dismantling super-hive-ships might be the case, following well behind the vanguard fleets.

The Imperium is a big place. There are a lot of places to hide away. Unless your cult is doing something big, no one will notice.

I don't think you understand how vast the Imperium is depicted as being.

It's like spam emails. You've got a spam filter. Your ISP provides it. You probably still occasionally see one or two that make it through. Some people respond to those, click on links in them, whatever - and this is why each one was sent to literally millions of accounts, often dozens of times. To get one person to click on it, infect their machine, give their money to the prince of Nigeria, whatever - you seed millions of machines. Tens of millions: you get ten clicks. A hundred million - a hundred clicks (actually the rate is much higher, but you see where this is going).

Genestealer cults only need one purestrain, or even just one hybrid of any generation, or simply an infected host after all the purestrains and hybrids are dead - one purestrain could infect a dozen individuals, send them all off in different directions, and those dozen infected would spawn a dozen cults. They gather their own supplies, they ensure their own survival, and eventually they reproduce genestealers in number and begin their uprising, by which time they've probably also sent off dozens of infected around their planets or offworld, starting with those unlikely to be caught - the fourth-gen, the human carriers. From those initial dozen you're easily talking about hundreds of sub-cults spawned from the first infected groups, and that's from one genestealer.

Or put another way: real-world contraception is something like 99.9% effective at preventing conception. If you have a population of 1000 couples, one of them's getting pregnant tonight and there's nothing more that you or they can do about that.

Things being statistically unlikely and your taking the best precautions against them don't make them impossible. In a galaxy-spanning empire of millions of interconnected worlds, you couldn't possible prevent genestealer cults with 100% success.

Holy shit, top tier post

>Are tyranids even biologically possible?
I hope not

Depends, energy loss would really be the only thing as everything is digested, even carbon dioxide, although IIRC they also suck hydrogen off stars so that's how they keep going. The real question is how they survive the depths of space

No. Tyranid biology was described by the Dark Eldar, the greatest scientists in the galaxy, as "fuck if I know, but that's some magic biology yo".

>There's some bullshit in the codex I believe about the tyranids just getting back the biological matter from their corpses, and so the horde never really loses numbers... but that's clearly bullshit, when you shoot flesh with a laser, flashlight or lascannon, it doesn't magically stay alive. And a lot of it is probably rotting before it can be gained back. ESPECIALLY if you use bolters; that's likely to fuck up everything.
Probably exploitable "bio-mass" would really be any compounds and elements that are useful for the Tyranids form of life. Exactly what form that is in probably doesn't matter so much.

Biology which is significantly better than anything you see on earth, using the same basic building blocks as earthly biology, developed only using evolution seems incredibly unlikely. I think it's safe to say that earth biology is already about as good as its possible to get without changing something dramatically.

As an engineered race which can use carefully built nano-structures which could never evolve from a natural cell they might be slightly more believable. I still find it very unlikely that you could make something massively more energy efficient than known organisms and tyranids are orders of magnitude more efficient that I think is likely to be achievable. Still, I'm not a biologist, let alone a vast alien superintelligence so I guess it's possible there are options I'm not aware of.

As a general rule though, any biological or nano type technology in fiction is likely to be way, way better than would be realistic. Evolution, given enough time, is an incredible engineer and if she can't work out how to do something it probably can't be done with the tools she has.

>I still find it very unlikely that you could make something massively more energy efficient than known organisms and tyranids are orders of magnitude more efficient that I think is likely to be achievable.

Actually I don't think combat tyranids are energy efficient. It's the other way around. They waste too much energy and are not supposed to live beyond a couple of engagements. After which they go back to biomass for rebuilding. Except for some centerpiece creatures that are worth to keep around.

For that they gain combat effectiveness and ability to use powerful weapons and armor.

Tyranids don't consume worlds to get energy.
They do it to increase their total biomass, and make more nids.
Consuming worlds is more akin to reproduction for nids, than it is to feeding.
Presumably they get most of their energy by photosynthesis via their hive ships that float in spesh.

Ultimately the problem is one of entropy. Tyranids can't just recycle biomass; it doesn't work like that. Every time matter breaks up, whether it's from death or decomposition or digestion, some energy is lost. Rebuilding that biomass requires more energy.

It'd be one thing if Tyranids were constructing Dyson spheres or something to harness enough energy to offset their growth rate, but they aren't. They appear to just get energy from nowhere.

Not to say that energy from nowhere isn't possible, because that's more or less what plants do. Photosynthesis creates energy and is ultimately responsible for almost all of the biological energy on Earth. But Tyranids don't do that, they consume other living material, which is a pretty darn inefficient way to create energy, especially considering just HOW inefficiently the Tyranids conquer planets.

It's a physics problem as much as it is a biology one, and without some sort of magical metabolism or the Shadow in the Warp providing some sort of nebulous entropy buffer, it's basically an insolvable one.

>Tyranids don't consume worlds to get energy.

You just need energy to create stuff. Matter is made of energy, bio or otherwise.

What makes you think that the nids don't photosynthesize?
Their ships are in space all the time, absorbing solar radiation.

That's wrong, though. Law of conservation of matter and law of conservation of energy. Matter and energy are wholly separate.

Nids need both matter/biomass for conquest, and energy to process that matter/biomass into something useful rather than just goop.

What makes you think they aren't? They have the DNA of everything they eat. You think they haven't eaten at least one plant to make big solar farms when they need energy?

Tyranids don't eat because they are hungry. They eat to expand and reproduce. Tyranids aren't a hive of angry bugs, they're an entire ecosystem optimized for war.

It's a scale problem. It's a fairly standard sci-fi issue, honestly. The full-scale reprocessing of all of the organic matter on a planet, down to the amino acids like what's described in the fluff, would take a MASSIVE expenditure of energy. Hive fleets are going to have to spend most of their photosynthesized energy just on homeostasis and propulsion.

After Tyranids take over a planet, everything gets slooped together and reabsorbed into the hive motherships, which then spit out more tabletop units as necessary. That's much less efficient than, say, cryostasis, because they're adding more and more layers of entropy into the mix.

Tyranid exoskeletons are another scale problem, especially for the titan-sized ones. Exoskeletons just don't distribute weight as efficiently for large creatures as an endoskeleton. Even if they had both, muscles bound to an exoskeleton would not give the level of agility Tyranids are described as having.

All of this stuff is fine, though. It doesn't have to be realistic to be fun. Ultra-hard sci-fi is usually quite boring.

Did you just say matter and energy aren't the same thing? That's completely wrong

You missed one, massive key point.
They also strip worlds of their atmosphere. Which is full of chemicals necessary for raw biology as we know it; oxygen, nitrogen, carbon, hydrogen.

Aside from raw living biomass, they consume many of the chemical molecules that are needed to be combined to make life. Even if they lose tonnes of biomass to incinerated organisms, say through atomic blasts or melta-guns, they are also ingesting the raw materials of life.

THEY HAVE PSYCHIC POWERS YOU RETARDS

OF COURSE THEY AREN'T BIOLOGICALLY POSSIBLE

THEY USE MAGIC ALL THE FUCKING TIME

MAGIC

THEY USE MAGIC TO EVOLVE, TO FIGHT, TO BREED, TO COMMUNICATE, TO TRAVEL, TO GROW...

THEY'RE MAGICAL SPACE BUGS

SOME OF THEM EVEN SHOOT LIGHTNING MADE OUT OF HUNGER FROM THEIR BRAINS.

Tyranids are just apex predators. They eat (all) other life, of course most of the energy is lost on the way. If a hivefleet is held off after it has expended the energy to spawn a surface invasion and all those atmospheric spores, it is basically crippled, depending on the size of the fleet. If it succeeds, it can double or triple in size, because they leave with several percent of the planet's mass (all the water, for a start)

In terms of pure physics sure but in terms of whats actually practical....?
Hell no, creating even a small amount of new matter would require astronomical amounts of energy if that's what the Nids were doing they probably wouldn't bother with planets at all they'd just envelope stars and suck up all the energy

They don't get all their noms soley from enemies and their dead you fuggin dingus. If they win the battle, the eat THE ENTIRE FUCKING BIOSPHERE.

Depending on the planet their is the potential for their to be many more times biomass planetside than there is in the entire fleet that came to nom it.

As far biological possibility?

It's mostly plausible.

Here on earth with have super organisms (species that have extremely close symbiosis and share a "body"), we have venom canons, beetles that piss burning acid out their ass, eels and fish that can sense electrical signatures and of course shit lightning to kill prey, we have bugs with fucking glue guns on their head that freeze prey in place by cumming glue all over them then they use their mouth knife (they literally have a thing that looks like a knife in their weird squishy mouth) to make an incision and then they suck their blood and guts out, we have creatures whose whole bodies are shaped and dedicated for one combat action (for a lack of better words) like assassin spiders (look that up and be creeped out) or giant mouthed fish that just succ hard as fuck and eat fish before they can blink, fucking snapper turtles, we have organisms that use other organisms DNA occasionally, we have frogs that give themselves compound fractures then shank their opponents with their broken bones, we have fucking nematodes, zombie fungus, mind controlling parasites and all manner of monsters .

Given the right nutrition, right environment, time and chance things like tyranids are actually pretty plausible.

However a hive mind as it is described is pretty far fetched though we have examples of super organisms and highly intelligent hive behaviour.

>The real question is how they survive the depths of space
Same way we do really. They just grow themselves a sealed exoskeleton instead of making one from cloth, rubber and metal.

Its better too think of tyranids not as hungry space bugs, but as highly advanced civilization that makes no distinction between animal and machine.

of course not you twat they're from 40k

I think the problem with Tyranids is that GW never figured out how they wanted to present them. Sometimes they are an eldricht horror and other times the bugs from starship troopers.

Why this matters to the OP is that they violate logic with no explanation for how fast they reproduce and feed on planets. Someone mentioned the laws of conversation of energy but to create a new tyranid would have to take time and energy. That's not how they are presented with fresh waves bring thrown into front lines like they are playing an RTS.

IMHO tyranids work best as a slow moving, inevitable, style enemy. I don't mean their actual TT play but their weakness should be that they are slowly entering the galaxy and that it takes time to do everything from eat a planet to produce a new organism. Essentially, it gives stakes to their menace.

This man speaks truth.

Good post Hitler.

>fourth sentence in the OP is "is their non-warp related stuff even plausible?"

Congrats, retard

>Orion's Arm
My nigga

You know how when you fart in your sleep and it gets trapped under your sack? That's exactly the process of a hive fleet taking a planet. Like when the sack and fart smells mingle, then it sneaks out when you wake up and the smell makes you throw up your grilled cheese? Tyranids.