What historical forces do you think could have defeated the Tyranid threat?

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**Melissia**

Peregrine wrote:
SomeRandomEvilGuy wrote:
It's plied in at least one place. I forget what codex but it states that when Tyranid Hive Fleets cross paths they tend to fight and consume each other and that the winner essentially becomes the size of both combined.

IOW "GW doesn't understand thermodynamics".

Pretty much. Though with the Warp, it may not always apply I guess? But I'd think it would apply to the Tyranids given their calming effect on the Warp around them.

**silverstu**

Lance845 wrote:

In fact, the same rumors that talked about fall of Cadia talked about a story ark that is supposed to be coming out that is a conclusion to/expansion on the Octaria fights. The Nid sources that talk about that fight talk about how they are constantly switching the battleground so the feeder organisms can consume all the dead and replenish. The hive fleet over the planet is swelling with so much biomass from the constant fighting that nid splinter fleets are breaking off and hitting other planets with Nids that are bigger than what most people generally expect because of the way they have adapted to fighting the growing orks.

Sorry to ask but where does this come from? I don't think I have come across this and I've been wondering what might shape what the Nids might do in the new fluff progressions.

**Crazyterran**

I thought the Waagh! Ghazgkull book confirmed that the Orks won Octarius?

**Snake Tortoise**

Iracundus wrote:
I don't think it has ever been explicitly said they recycle with 100% efficiency in energy and mass. Normally there are tropic level losses in energy, which on Earth is about 90% loss between levels. That is why for example it takes 10 tons of plants to create 1 ton of herbivore flesh, and in turn it takes about 10 tons of herbivore flesh to create 1 ton of carnivore flesh. So similarly it may take 10 Termagant corpses consumed to recreate 1 Termagant.

However, the Tyranid consumption ecosystem as written back in 3rd edition does get energy inputs from the sun and from geothermal sources, so it is not a closed system. The Tyranid flora apparently has high efficiency photosynthesis, fast growth, and sucks nutrients from the soil quickly. When these Tyranid plants are consumed by Rippers and other consumers it is essentially an energy input, as these Rippers in turn can then be broken down to drive the generation of actual Tyranid combat organisms. The Tyranids access geothermal energy by getting suicidal creatures to drill downwards. We know that extremophile bacteria can thrive in such geothermal springs or hotspots on Earth. Rapid growing Tyranid versions of these would again be another form of energy input when these are consumed to feed the rest of the Tyranid ecosystem.

Tyranids may not be immune to attrition but they utilize resources on a scale beyond most other races. Even Orks are reliant on a technological economy, as they still use guns and ammunition, which still requires Grots to mine and refine the raw materials. No, a Tech-Priest mistakenly believing their gear only works because of belief does not make it so, as evidenced by the fact that human Ork Hunters on Armageddon were able to use captured Ork guns. Tyranids use all the unproductive lands like barren wastelands and tundra that other races leave unutilized, as even those lands have biomass that can be used and harnessed. It appears it takes far less time for the Tyranid flora to establish itself in an area and start leaching it dry of nutrients than it takes for humans to establish a productive mine for example.

War detritus is also digested. The 3rd edition Tyranid Codex described Tyranid flora breaking down the steel and plastic ruins of an Imperial outpost for absorption. By contrast, the Tyranid dead are effectively useless to the enemy, save perhaps as firewood. Tyranid dead cannot be used as food because again the 3rd edition Tyranid Codex describes them as being infested with smaller Tyranid organisms (like mites or bacteria) that sicken anything that consumes them.

A human without technology does not pose much of a threat to a Tyranid. An Ork without weapons poses more threat but Tyranid combat organisms still generally are superior or more numerous. All the technological societies require civilians to support their war production, whether this be Grots or hive city workers, and discrete fixed infrastructure like factories and mines. The Tyranids don't really have this supply vulnerability for their on-planet forces. Rather they appear to be more decentralized. Sure there are digestion pools but destroying one does not appear to break supply chains in the way that destroying a critical factory can for other races.

Pretty much all the major victories against Tyranids in the fluff have ultimately boiled down to defeating them in space and then mopping up remaining disorganized ground forces, not defeating them in a face to face ground war because once they make planetfall, they start utilizing the entire planet's biosphere's energy content. Unless all Tyranids are completely wiped out on the surface (which is extremely hard to do), they hide away until they regenerate new forces in out of the way hard to monitor places. Eventually they either wear down the enemy or grow to sufficient size that they can overwhelm the enemy. That is precisely what they did on Gorala in the 5th edition Tyranid Codex to defeat the Orks.

Thanks, that's a great answer

I suppose defeating them in a ground war could depend on how quickly the nids can replenish numbers. They already have a great advantage in being able to harness any biomass to create their armies, so I don't think it would be unreasonable that a defender could win a string of victories, blunt the attack and then have a time period where if they go on the counter attack and start methodically killing tyranid organisms the tyranids aren't able to respawn in time. I feel like that would balance things somewhat and allow more interesting fluff with campaigns ebbing and flowing rather than just being pure tyranid offense vs opponent defence.

I think a really cool novel could be written from the perspective of the orks fighting tyranids. It wouldn't have to be the Octavius (?) war we know about- it could be another planet entirely. It would be a great opportunity to showcase both factions, update both codices, maybe release a starter box with two xenos factions and... I'm getting carried away here, but it would be very cool.

**ProwlerPC**

Crazyterran wrote:
I thought the Waagh! Ghazgkull book confirmed that the Orks won Octarius?

It does. Twice. Once in the full story of Ghazzys travels and again in the summary of the Great Waaaaagh! To some it never happened unless they buy the book and read it.

**silverstu**

ProwlerPC wrote:
Crazyterran wrote:
I thought the Waagh! Ghazgkull book confirmed that the Orks won Octarius?

It does. Twice. Once in the full story of Ghazzys travels and again in the summary of the Great Waaaaagh! To some it never happened unless they buy the book and read it.

Good to know- the Nid codex just had it set as a meat grinder for both sides [I hadn't read any Ork stuff so I hadn't heard any progress on the story].

I wonder if the DE combining the two hive fleet's DNA will have any influence on the story as the Eldar where desperate to avoid that happening, they would need to be absorbed by a fleet again though, tricky as they are at large in Commoragh and I don't think "taxi for Nid" will work there somehow..

**Lance845**

silverstu wrote:
Lance845 wrote:

In fact, the same rumors that talked about fall of Cadia talked about a story ark that is supposed to be coming out that is a conclusion to/expansion on the Octaria fights. The Nid sources that talk about that fight talk about how they are constantly switching the battleground so the feeder organisms can consume all the dead and replenish. The hive fleet over the planet is swelling with so much biomass from the constant fighting that nid splinter fleets are breaking off and hitting other planets with Nids that are bigger than what most people generally expect because of the way they have adapted to fighting the growing orks.

Sorry to ask but where does this come from? I don't think I have come across this and I've been wondering what might shape what the Nids might do in the new fluff progressions.

I don't remember where it was on this forum. I saw it requoted awhile back. There was supposed to be 5 major stories moving the fluff forward or some such.

Fall of Cadia - Chaos Vs IoM
The Eldar Vs Slaneesh
Nids Vs Orks and the progress on Octaria
Tua Vs Eldar (I think?)
Necrons somewhere?

So far 2 of the 5 stories have been happening or being built towards in gathering storm.

Wish I could find that damn post...

**Exergy**

Snake Tortoise wrote:

I suppose defeating them in a ground war could depend on how quickly the nids can replenish numbers. They already have a great advantage in being able to harness any biomass to create their armies, so I don't think it would be unreasonable that a defender could win a string of victories, blunt the attack and then have a time period where if they go on the counter attack and start methodically killing tyranid organisms the tyranids aren't able to respawn in time. I feel like that would balance things somewhat and allow more interesting fluff with campaigns ebbing and flowing rather than just being pure tyranid offense vs opponent defence.

I think a really cool novel could be written from the perspective of the orks fighting tyranids. It wouldn't have to be the Octavius (?) war we know about- it could be another planet entirely. It would be a great opportunity to showcase both factions, update both codices, maybe release a starter box with two xenos factions and... I'm getting carried away here, but it would be very cool.

They commit a huge amount of their biomass to an attack, their whole strat is to overwhelm with massive numbers. If they win they then re consume all their loses, plus the loses of the enemy, but most of the useful biomass they are eating is probably their own. That is if they win.

If they get beaten back from a planet, they lose all that biomass. They might try to take the planet again, but their second assault is going to be a lot weaker than the first, because they just lost a huge amount of that biomass on the first attack. If the first attack suitably weakened the enemy, they might still prevail but if not they are going to run into trouble.

**Lance845**

ProwlerPC wrote:
Crazyterran wrote:
I thought the Waagh! Ghazgkull book confirmed that the Orks won Octarius?

It does. Twice. Once in the full story of Ghazzys travels and again in the summary of the Great Waaaaagh! To some it never happened unless they buy the book and read it.

Waagh! Ghazgkull has a 1 page story about him joining the fight on a single planet and winning there. That same story talks about how the nids are still all over the entire sector fighting. It also has ZERO mention of fighting the actual fleets, which would mean any victory on the ground is meaningless until somebody gets into orbit and starts killing hive ships.

In fact: the last 2 entries on the time line are:

"865999.M41 The Tyranids Return
Just like Ghazkill Thraka, the Hive Mind is known for learning from past battles. New tactics and creatures had been evolved and at this time they were unleashed. As the Ork fleet and bio-ships clash in space, the assault rains down upon Octaria. The Tyranid attack waves are of an intensity that has never been seen before. Once more the planet shakes to the sounds of unending battle.

886999.M41 Messages To Armageddon
In between leading attacks into the Tyranid masses, Ghazghkull checks on his ladz back on Armageddon. Shifting his mind to the Great Green, Ghazghkull witnesses Zagboss Skargrim carve another notch on the barrel of this Warbike's dakkaguns to make another Astra Militarum battalion ridden dwn and destroyed. In his most threatening voice, Ghazghkull warns Zagboss that it is the Space Marines that he needs to worry about, and if he really wants to earn his favour, he'd better start hunting them. Pleased with the look of awe and admirations on the Evil Sunz Warlord's face, Ghazghkull briefly visits each of his ruling commanders, dispensing tactical advice, dropping in a few grunts of well-deserved acclaim, and admonishing those that were not driving their troops as hard as they ought. Orkimedes believes he will soon perfect the tellyporta so that Ghazghkull can transport himself all the way back to Armageddon as wuck as you could stomp a grot. Naturally, Ghazghkull does not tell any of his subordinates this news. If they thought hearing his voice was awe-inspiring - just wait until he turned up beside them barking orders.... "

In conclusion... Octraria Sector is buisness as usual and nothing has changed. Ghazghkull is getting ready to leave before the fight is even done.

**John Prins**

Ah, GW, you so silly. If you have energy sources independent of consuming biomass, you don't need to invade planets to create more biomass. A single star system's Oort cloud probably contains more raw materials than all the hive fleets put together. Scoop up some asteroids with your big ships, disassemble them with bacteria, digest the bacteria to make larger organisms.

The tyranids need a more compelling reason to invade planets - even lugging all that biomass out of a gravity well is an enormous amount of energy to commit. Probably the best reason for them to do so is for unique genetic information so they can adapt and evolve better. But if the tyranids never invaded another planet, replenishing their biomass is a trivial exercise. There is no shortage of raw materials to be had in space.

**Exergy**

John Prins wrote:
Ah, GW, you so silly. If you have energy sources independent of consuming biomass, you don't need to invade planets to create more biomass. A single star system's Oort cloud probably contains more raw materials than all the hive fleets put together. Scoop up some asteroids with your big ships, disassemble them with bacteria, digest the bacteria to make larger organisms.

The tyranids need a more compelling reason to invade planets - even lugging all that biomass out of a gravity well is an enormous amount of energy to commit. Probably the best reason for them to do so is for unique genetic information so they can adapt and evolve better. But if the tyranids never invaded another planet, replenishing their biomass is a trivial exercise. There is no shortage of raw materials to be had in space.

This!

They need some other motivation than resources, because the planets they are going after are just about the worst way to acquire the resources they are said to need. If they were coming from a far away galaxy that they had completely consumed, there wouldn't be anything left of that galaxy because they would have consumed the stars.

If they were looking for unique and new DNA like the AdMech searches for STCs that would be ok.
Or if they hated all other life and wanted to destroy it, they would basically be weird fleshy oldcrons.
Some better motivation than "ggrrrrr I am hungry and want to eat you"

**Lance845**

Exergy wrote:
John Prins wrote:
Ah, GW, you so silly. If you have energy sources independent of consuming biomass, you don't need to invade planets to create more biomass. A single star system's Oort cloud probably contains more raw materials than all the hive fleets put together. Scoop up some asteroids with your big ships, disassemble them with bacteria, digest the bacteria to make larger organisms.

The tyranids need a more compelling reason to invade planets - even lugging all that biomass out of a gravity well is an enormous amount of energy to commit. Probably the best reason for them to do so is for unique genetic information so they can adapt and evolve better. But if the tyranids never invaded another planet, replenishing their biomass is a trivial exercise. There is no shortage of raw materials to be had in space.

This!

They need some other motivation than resources, because the planets they are going after are just about the worst way to acquire the resources they are said to need. If they were coming from a far away galaxy that they had completely consumed, there wouldn't be anything left of that galaxy because they would have consumed the stars.

If they were looking for unique and new DNA like the AdMech searches for STCs that would be ok.
Or if they hated all other life and wanted to destroy it, they would basically be weird fleshy oldcrons.
Some better motivation than "ggrrrrr I am hungry and want to eat you"

There are some VERY rough ideas that the force behind the nids evolution and the hive mind might be a C'tan. It's all REAL tenuous though. There is a C'tan called "The Swarm" and a C'tan called "The Devourer". One of those is sealed up inside a Dyson Sphere outside the Galaxy and the Nids apparently actively avoided it on their way to us. Who knows what thats supposed to mean.

**Waaaghpower**

To my understanding, the only way to really, effectively beat Tyranids is to take them out in space combat, because once they land on a planet, that planet is effectively screwed unless you have nigh-unlimited manpower and resources to purge all of the Tyranid spores. If you kill them in space, though, they have no new source of Biomass until they find a new planet to devour.

I generally dislike this aspect of Tyranid fluff, though, because their very design makes them pretty much unstoppable if you actually stop and consider it. Even if they have to use preexisting biomass and can't just harvest raw resources, there's no reason that they couldn't just have some 'Farm' planets that grow moss and lichen or whatever else they need for Biomass, and they just eat it up to replenish forces.
And, since they can reuse their own biomass if they get killed (the only way to prevent this being to torch the bodies of the dead,) there's no realistic way that any war could be won against them - You would lose any long seige, because the Tyranids only take casualties if they are completely wiped out on a given battlefield, and then the entire area is doused in promethium and burned. If you lose, you lose. If you tie, you lose. If you win, but can't unequivocally claim the battlefield, you lose. If you cause a million casualties and only lose three Guardsmen, but ultimately get pushed back due to immensely overwhelming numbers, well, you just lost three Guardsmen while the Tyranids lost nothing.

**Iracundus**

John Prins wrote:
Ah, GW, you so silly. If you have energy sources independent of consuming biomass, you don't need to invade planets to create more biomass. A single star system's Oort cloud probably contains more raw materials than all the hive fleets put together. Scoop up some asteroids with your big ships, disassemble them with bacteria, digest the bacteria to make larger organisms.

The tyranids need a more compelling reason to invade planets - even lugging all that biomass out of a gravity well is an enormous amount of energy to commit. Probably the best reason for them to do so is for unique genetic information so they can adapt and evolve better. But if the tyranids never invaded another planet, replenishing their biomass is a trivial exercise. There is no shortage of raw materials to be had in space.

Ask yourself why everything on Earth isn't an autotroph like plants when there are sources of energy from the sun or geothermal vents? Why are there herbivores or carnivores if there is no need to hunt other animals. One factor is time. Eating another organism that has already done the slow boring work of making organic matter using other energy sources is a quicker way of getting a concentration of energy. The same could be argued for Tyranids. Eating a planetary biosphere is a way of getting both biomass and new genetic information, the two needs described as driving the Tyranids. The Tyranids can be viewed as a galactic scale animal or apex predator and the planetary biospheres as the grass or herbivores.

Automatically Appended Next Post:

Lance845 wrote:
Exergy wrote:
John Prins wrote:
Ah, GW, you so silly. If you have energy sources independent of consuming biomass, you don't need to invade planets to create more biomass. A single star system's Oort cloud probably contains more raw materials than all the hive fleets put together. Scoop up some asteroids with your big ships, disassemble them with bacteria, digest the bacteria to make larger organisms.

The tyranids need a more compelling reason to invade planets - even lugging all that biomass out of a gravity well is an enormous amount of energy to commit. Probably the best reason for them to do so is for unique genetic information so they can adapt and evolve better. But if the tyranids never invaded another planet, replenishing their biomass is a trivial exercise. There is no shortage of raw materials to be had in space.

This!

They need some other motivation than resources, because the planets they are going after are just about the worst way to acquire the resources they are said to need. If they were coming from a far away galaxy that they had completely consumed, there wouldn't be anything left of that galaxy because they would have consumed the stars.

If they were looking for unique and new DNA like the AdMech searches for STCs that would be ok.
Or if they hated all other life and wanted to destroy it, they would basically be weird fleshy oldcrons.
Some better motivation than "ggrrrrr I am hungry and want to eat you"

There are some VERY rough ideas that the force behind the nids evolution and the hive mind might be a C'tan. It's all REAL tenuous though. There is a C'tan called "The Swarm" and a C'tan called "The Devourer". One of those is sealed up inside a Dyson Sphere outside the Galaxy and the Nids apparently actively avoided it on their way to us. Who knows what thats supposed to mean.

It means there is no sense attacking a heavily defended Necron stronghold that offers little or no return in biomass. That is a straightforward strategic reason for avoiding the Dyson Sphere especially when there are so many other richer soft targets elsewhere.

**Lance845**

Iracundus wrote:

It means there is no sense attacking a heavily defended Necron stronghold that offers little or no return in biomass. That is a straightforward strategic reason for avoiding the Dyson Sphere especially when there are so many other richer soft targets elsewhere.

There is a big difference between not stopping and going out of your way to take the long way around in an attempt to avoid it. Heavily defended is an assumption. The sphere has never been described in any source in any amount of detail. It exists and a C'tan is supposed to be inside it. That is all we got.

**John Prins**

Iracundus wrote:

Ask yourself why everything on Earth isn't an autotroph like plants when there are sources of energy from the sun or geothermal vents? Why are there herbivores or carnivores if there is no need to hunt other animals. One factor is time. Eating another organism that has already done the slow boring work of making organic matter using other energy sources is a quicker way of getting a concentration of energy. The same could be argued for Tyranids. Eating a planetary biosphere is a way of getting both biomass and new genetic information, the two needs described as driving the Tyranids. The Tyranids can be viewed as a galactic scale animal or apex predator and the planetary biospheres as the grass or herbivores.

Plants have to compete for access to the sun as well (that's why we have tall trees). Herbivores sidestep that competition. Carnivores sidestep the competition issues that herbivores will have. Most of the specialization in nature has been to find an environmental niche that has less competition, or to be more versatile so as to take advantage of any opportunity that comes by.

Think of the energy requirements to first, consume a planet's entire biomass (digestion requires energy expenditure, though you often get more back), THEN haul that biomass into orbit. It takes 10 joules of energy to raise 1kg upwards 1 meter. Geostationary orbit above earth is almost 36000 km above Earth, 36000 x 1000 x 10 = 360,000,000 Joules to raise 1 kg to that height.

For reference, fat has an energy density of 37 MJ/kg (37,000,000 Joules). So it takes about 10kg of fat to raise 1kg of fat to orbit. Add in the energy losses in rendering the whole planet down, and having to re-grow your entire army after the fact, means it's even less efficient (below 10% energy return - around 15% if they're harvesting lots of Methane).

This is NOT a cost effective means of acquiring energy, meaning Tyranids must have other, better sources of energy (living fusion engines, direct taps to warp energy, etcetera).
Assuming they have that, acquiring raw materials from anywhere other than a steep gravity well is a far, far better option.

I'm totally onboard with the idea that the Tyranids invade planets for novel genetic patterns. Any functioning biosphere will have them - open space, not so much. But it's basically impossible to deny tyranids access to biomass, the raw materials for it are EVERYWHERE and harvesting and converting it is relatively trivial for an interstellar race, and rendering asteroids down to dust for bacterial to consume is probably quicker than growing feeder tubes to geostationary orbit.

The Imperial tactic of torpedoing tyranid invaded planets only works because they can harass the tyranid fleet to keep them from harvesting asteroids for raw materials, which would require the tyranid fleet to be spread out and vulnerable to attack. But operating normally, the tyranid fleet can get all the biomass it ever needs without setting one clawed foot on a planet.

**Iracundus**

Lance845 wrote:
Iracundus wrote:

It means there is no sense attacking a heavily defended Necron stronghold that offers little or no return in biomass. That is a straightforward strategic reason for avoiding the Dyson Sphere especially when there are so many other richer soft targets elsewhere.

There is a big difference between not stopping and going out of your way to take the long way around in an attempt to avoid it. Heavily defended is an assumption. The sphere has never been described in any source in any amount of detail. It exists and a C'tan is supposed to be inside it. That is all we got.

Necrons have starships. The Tyranids have fought Necrons before but this appears to have always been in the context of the Necrons being on planets that have (redeveloped) biospheres. The Tyranids are therefore aware of the Necrons and what level of resistance they are capable of. There is no point in getting near a known dangerous enemy when there is no expected return for fighting them. Giving them a safe berth is an entirely reasonable decision without the necessity of invoking unsubstantiated conspiracies about someone controlling them.

The first Necron Codex gave a description of the Dyson Sphere from the perspective of an abducted Tech-Priest. It is an active C'tan and Necron site. This was also from the time when the Necrons were still doing their Great Work of sealing off real space from the warp through their monolithic constructs just like with the Cadian pylons. Therefore that area of the warp near the Sphere would have been relatively becalmed.

We know from the BFG and 3rd edition Tyranid Codex that the hive fleets select targets based upon psychic signals from Genestealer infestations and failing that from spectrographic analysis of stars likely to have life bearing worlds. Both of these methods would have produced no positives with the Sphere.

So to summarize, there is a region of space that gives none of the positive signals suggesting there is worthwhile feeding. The warp there is becalmed there (this was before the retcon of the Narvhal). There is a known enemy there that can put up a fight. Tyrants scoutships to that area have either failed to return or have returned reporting no significant feeding available. That area is the equivalent of a desert to the hive fleets. There is no reason at all for them to even get near the area let alone cross it directly.

**Peregrine**

John Prins wrote:
I'm totally onboard with the idea that the Tyranids invade planets for novel genetic patterns.

I'm not. There's no reason at all to believe that an alien species from outside our galaxy would have genetic material that is compatible with DNA, and there's even less reason to believe that they'd be compatible with complete genes. The whole "invade and eat our DNA" concept is nonsense written by people who don't understand biology.

**Otto Weston**

Peregrine wrote:
John Prins wrote:
I'm totally onboard with the idea that the Tyranids invade planets for novel genetic patterns.

I'm not. There's no reason at all to believe that an alien species from outside our galaxy would have genetic material that is compatible with DNA, and there's even less reason to believe that they'd be compatible with complete genes. The whole "invade and eat our DNA" concept is nonsense written by people who don't understand biology.

It may simply be an oversimplification.
I imagine Tyranid 'assimilation' of other Species to be their biological equivalent of an RnD department; Norn Queens study organisms with unique behaviours, characteristics or abilities to find out how its accomplished and then using that research to adapt Tyranids genetically to mimic features they desire.

**Lance845**

Nothing else in 40k fluff makes any sense when placed under a microscope why would anyone expect nids to hold up?

**Spetulhu**

Two chimpanzees with sharp sticks, probably. Nothing as stupid as the tyranids could ever have survived, much less managed to get anywhere. Living ships is a stupid idea - the radiation in space is not funny, it's why we still think a trip to Mars is too dangerous. The poor things are dead before reaching the edge of their original solar system. Soldiers with weapons grafted on and no way of refilling energy? What a waste. And ofc, having exoskeletons and bug-like bodies in general at that size means they can't do anything on a planet except lie down and wait to asphyxiate if they didnt die from the crushing force of real gravity.

Once they meet intelligent opposition (said chimps) they'll quickly fold.

**Exergy**

Peregrine wrote:
John Prins wrote:
I'm totally onboard with the idea that the Tyranids invade planets for novel genetic patterns.

I'm not. There's no reason at all to believe that an alien species from outside our galaxy would have genetic material that is compatible with DNA, and there's even less reason to believe that they'd be compatible with complete genes. The whole "invade and eat our DNA" concept is nonsense written by people who don't understand biology.

It's slightly more plausible than them needing to consume biomass. It is highly doubtful an extra galactic race would use the same amino acids that we do.

Automatically Appended Next Post:

John Prins wrote:

Think of the energy requirements to first, consume a planet's entire biomass (digestion requires energy expenditure, though you often get more back), THEN haul that biomass into orbit. It takes 10 joules of energy to raise 1kg upwards 1 meter. Geostationary orbit above earth is almost 36000 km above Earth, 36000 x 1000 x 10 = 360,000,000 Joules to raise 1 kg to that height.

For reference, fat has an energy density of 37 MJ/kg (37,000,000 Joules). So it takes about 10kg of fat to raise 1kg of fat to orbit. Add in the energy losses in rendering the whole planet down, and having to re-grow your entire army after the fact, means it's even less efficient (below 10% energy return - around 15% if they're harvesting lots of Methane).

This is NOT a cost effective means of acquiring energy, meaning Tyranids must have other, better sources of energy (living fusion engines, direct taps to warp energy, etcetera).
Assuming they have that, acquiring raw materials from anywhere other than a steep gravity well is a far, far better option.

Gravity isnt linear across distance. Getting to geosync height doesnt mean you are in geosync orbit. You have to increase your velocity, which actually takes more energy. The earths gravity well is 62.6 MJ/kg deep at the surface. So a little less than double your calculation.

Either way, I agree it's a dumb way to get biomass or energy. It's the same with a lot of bad scifi out there. "The aliens came to earth for our water." Water is incredibly common in the universe. You wouldnt bother going all the way to earth to steal the water.

**John Prins**

Peregrine wrote:
John Prins wrote:
I'm totally onboard with the idea that the Tyranids invade planets for novel genetic patterns.

I'm not. There's no reason at all to believe that an alien species from outside our galaxy would have genetic material that is compatible with DNA, and there's even less reason to believe that they'd be compatible with complete genes. The whole "invade and eat our DNA" concept is nonsense written by people who don't understand biology.

DNA is just information about how to perform certain chemical operations. Presumably the Tyranids are experts at disassembling life forms and learning how to replicate their particular chemical structures using whatever alien genetic material they employ.

So the tyranids don't want to copy human DNA, but they might find that human DNA contains useful procedural information for growing tooth enamel. Then they figure out how to adapt their own biology to copy the process.

Anyway, the tyranids need a compelling reason to eat planets, and 'genetic information' is more plausible than 'raw materials'. Really, it could just be 'eliminate competition', as any biosphere could eventually produce competition for the Tyranids, so why not consume biospheres? Still, tyranids could use the equivalent of cyclonic torpedoes and just destroy a biosphere more easily and quickly.

Or you could just assume that the Hive Mind is actually driven by completely base urges that overrides the higher order thinking of its most intelligent swarm members. So the Norn Queens might well know that harvesting planets for biomass is inefficient, but the Hive Mind wants to eat planets and ignores the Norn Queens.

**Formosa**

Lance845 wrote:
Anyone who says anything imperium of man has could win is out of their mind.

The only people with the advantages needed to actually win a war of attrition with the nids (and no matter who you are it IS a war of attrition) is the Necrons.

The orks are super numerous, but that is actually their disadvantage. The orks are currently embroiled in a massive war with leviathan and leviathan keeps bait and switching the battlefield while it devours and reuses the biomass. The orks loose numbers that take time to replenish. The nids gain back all the biomass of the fallen nids PLUS the biomass of any fallen orks and can pump out the next generation I'd nids as quickly as they can be devoured

Necrons on the other hand provide no biomass for the nids to grow their numbers. Cannot be fooled into giving up one battlefield to chance another, have weapons that can destroy the nids bodies on a molecular level and thus deny the nids easy access to the biomass, and have technology that can wink out stars as easily as you swipe your phones touch screen.

Problem is necrons are too split on whether they even give a gak enough to fight the nids. .

That is just the opinion of a magos biologist, not a fact, the fluff has shown several times that as little as a chapter can defeat a splinter fleet, a unified crusade imperium would wipe the floor with the tyranids, it would be a tough fight but a fight they would win, I think you underestimate just how many marines they could pump out, the tech that is extremely effective against tyranids, volkites, phosphex, rad weapons, battle automata etc

**123ply**

People seem to hate the fact that Tyranids are written to be practically unstoppable, but I love that. Tyranids are supposed to be an undefeatable, ultra regenerative swarm that kills everything and anything. The sense of hopelessness when facing the Tyranids.leviathan is how they contribute to the grim dark setting of wh40k. If there was any hope to defeat them, would they still be scary?

**hordrak**

Not only tyranids can consume all dead, orks alo can. Their biology permits them to devour even stouns to get minerals for their bodies, so they can also consume other dead orks and dead tyranids. Plus they release millions of spores in battle, plus thouse spores grow quicker so orks are just as adaptible to losses as tyranids. Tyranids are also bound to a role, but orks grow bigger and stronger, up to the points where they can deal with bio-titans personaly. Orks also can kill synaps creatures to cut lesser nids of the hive mind, while orks don't have similar weaknesses. Only if you kill the warboss can you make them squabble, but that is much harder.

**CREEEEEEEEED**

Spetulhu wrote:
Two chimpanzees with sharp sticks, probably. Nothing as stupid as the tyranids could ever have survived, much less managed to get anywhere. Living ships is a stupid idea - the radiation in space is not funny, it's why we still think a trip to Mars is too dangerous. The poor things are dead before reaching the edge of their original solar system. Soldiers with weapons grafted on and no way of refilling energy? What a waste. And ofc, having exoskeletons and bug-like bodies in general at that size means they can't do anything on a planet except lie down and wait to asphyxiate if they didnt die from the crushing force of real gravity.

Once they meet intelligent opposition (said chimps) they'll quickly fold.

It's a shame this comment was ignored.

**Melissia**

Some things just aren't worth responding to.

**SagesStone**

The men of iron.

**Deadshot**

Orks: too much biomass and lack of tactics, see Gholora Swarm
Deldar: No chance
Modern Imperium: No chance on a long enough timeline
DAoT Imperium: Too little info, maybe
Men of Iron: Maybe
Necrons: Best chance
Eldar Empire: Shadow in the Warp at that scale would fry their tiny brains like bacon
Tau: No chance, see Gorgon, and that was a tiny Hive Fleet by comparison
Chaos: Maybe but see Daemons vs Nids for example of why its a toss-up for plot armour to decide