Tyrannid question.

Firstly, what with the Tyranids supposedly being the eventual Doom of the Galaxy, the question is: How long could this take? Do they have a Warp Capacity of some kind? If not, eating their way across the Galaxy is going to take a hell of a long time. Even if they are Warp capable it could still take awhile.

So while resistance may be futile, it is conceivable that the end of all life in the Galaxy could be so far into the future could be so far off as to not matter; certainly not for the vast majority of people/xenos.

So, how long? Firstly without Warp Capacity. Secondly with.

It depends on the fluff. It has been stated that they do not traverse the Warp. They travel in real-time and go into stasis while moving between interstellar bodies and between galaxies. It has also been stated that they do travel through the warp by some unknown capacity but again enter stasis while traversing the warp.

In the current 4E Tyrannid Codex, I believe one Inquisitor gives a number of years before the Tyrannids would reach Terra as around a century. It also implies that the Hive Fleets encountered so far have just been the advance elements of the true Hive Fleet. A Hive Fleet so massive that it spans a width of many, many light years.

If the fluff is accurate, then the Tyrannid Hive Fleet would comprise so many elements as to be unstoppable. It could be a fleet of many billions of space craft and an untold number of craft capable of producing ground troops. Additionally, they could produce more elements from biomass accumulated from each conquered world. They are kind of like a galactic swarm of locusts. They were even compared in this way at one point. They consumed all life in a galaxy and then moved onto the next.

If they are unable to attain warp travel or faster than light travel then it would many thousands of years to devour a galaxy. Traveling interstellar distances at sub-luminary speeds takes a great deal of time. Even with warp travel, due to the nature of the warp, the Hive Fleet elements may have difficulty arriving at the correct location or even the correct time to mount a massive invasion.

For instance, since the Warp is a realm which bends both space and time, perhaps the Tyrannid main Hive Fleet is composed of twenty billion space craft. Let's say three percent are tossed into the wrong area on exiting the warp. If my math is right that gives about 600 million vessels not arriving at the correct location. That might account for some of the Nid attacks which seem to have snuck into cordoned space. If one percent are lost in time, that could account for all kinds of anomalies like the Ymargl Genestealers, Zoats, Catachan Devils and all manner of other weird occurrences.

The short answer is, if they are co-ordinated and warp-capable, a Hive Fleet could devour a world in only a few days. There are a lot of worlds out there but you get the idea. Some worlds could fight off a small Hive Fleet but would have little chance against a large Hive Fleet.

If they were not warp-capable, the Imperium could fall within a century since the main Fleet would go through the heart of the Imperium. If the Fleet is not as massive as Leviathan makes it seem, it could take many centuries or even millenia to wipe out the Imperium and vastly longer to devour the rest of this spiral arm and then the rest of the galaxy. But since galactic bodies, such as our own galaxy, are in motion, perhaps the Tyrannids would not consume the entire galaxy. They may conserve energy by letting galactic movement do some of the work for them and simply devour whatever is nearby.

Just some ideas rattling around in my head.

They'd need warp travel to be a century away from Earth. Most of the maps indicate the closest main fleet (Leviathan I believe) is around 20-30,000 light years away from Earth ([URL="http://en.wikipedia.org/wiki/File:236084main_MilkyWay-full-annotated.jpg"]here's a good pic of the galaxy with scale[/URL]). The galaxy itself is around 100,000 light years across, so without warp travel they'll be going for a looooooong time (Warhammer 440,000 anyone?).

Still, even at peak efficiency they're still going to take a long time. 150 years to Terra seems to indicate a direct path and minimal opposition. Dubious at best.

Hopefully the new Codex will shed more light on the issue.

I somehow feel that while they will ultimately win it's going to take many thousands of years.

A last thought: could the Emperor be calling them, somehow? If he wants release from the Golden Throne the Tyranids could accomplish that. And if so, what happens then? Does the new "god" destroy the Tyranid, burn out the Hive Mind with Psychic Force? Unite what's left of the Imperium and start again?

After all, there won't be much resistance in the outer reaches of the galaxy once the 'nids have been and gone.

Just a thought.