Letrii said:

All interstellar travel is via the Warp in some way - it's too slow otherwise. Considering that the tithe is frequently food or soldiers, the swiftness inherent in Warp Travel is an absolute necessity.

Remember, even two worlds in the same subsector are likely to be several lightyears apart, an insurmountable distance for vessels travelling at sub-light speeds.

Letrii said:

I agree with N0-1, any destination outside the same solar system would be way too far to travel without using the Warp. And frankly, if all (or even most) tithes paid stayed within the solar system they came from, what would be the point of paying them? Just keep the money on your little world and use it to suit the Emperor's will.

As far as the OP's concerns about how people communicate over such long distances, the Imperium maintains its hold largely because it follows something resembling a feudal structure of government. In other words, there would be frequent real-time communication across a planet (or a few planets if they happen to be in the same solar system,) there would be periodic communications with a sector authority (say on a monthly basis) and then the sector authority would report to the Administratum on Holy Terra once or twice a year. There may well be more than three layers to this, mind you. I'm not quite that intimate with the fluff to say for sure.

Point being, each planet has its own governor, in charge of that world. If he does a crappy job and the people rebel, odds are the Emperor doesn't even care, as long as whoever takes his place keeps paying the tithes. (As far as "predicting the arrival of tithes" I'm sure there's a certain window of time it's expected to arrive in, accounting for some Warp variation.) If a planet misses a certain number of tithes, THEN the Imperium would respond, probably by sending an Inquisitor to find out what happened and kick some asses until the tithes resume. Calls for help from the planet are almost irrelevant at that point. If one arrives on time, okay, otherwise *shrug.* As long as their money keeps flowing.

Larger threats like the Tyranids or an Orc Waaagh would probably consume dozen of planets before the Imperium was actually able to respond in force. Certainly the initial planets who actually sent a call for help would be wiped out before help arrived. The Imperium would probably even account for that and send help to nearby planets instead of the one that cried wolf. The thing is that even "dozens of planets" is a drop in bucket compared to how large the Imperium is. Horryfing? Yes. Especially for people living on fringe worlds where this sort of thing is likely to start. But a disaster for the Imperium as a whole? Hardly.

There would be fleets in each sector, as someone said, and of course the whole reason the Inquisition exists is so there's someone who can make executive decisions in the field without constantly communicating with a central authority. Although the Imperium maintains a unified appearance, it is largely composed of independent planets and coalitions that all claim loyalty to a central figurehead. Odds are the big reason most people claim that loyalty is because they're scared shitless of the idea of going it alone. Also, periodically an Inquisitor will visit their planet looking for "corruption" where 9 times out of 10 "corruption" is "saying anything that isn't directly kissing the Emperor's ass." I would imagine the actual number of Chaos cults and alien incursions is pathetically small, but the game focuses on those over the overwhelming majority of "bullying" cases because it makes for a more entertaining story for us , the players.

I could be a real ass and say that the Emperium of Man does not exist. It is merely a figment of the imagination of some writers and illustrators who want to fap to nazi imagery.

Now, with that out of the way I can also say something actually constructive, or at least thoughtful..

I think of the Emperium of Man as a dying beast. It was slain ten thousand years ago by the Horus Heresy, but the massive size of the beast means that the body has not realized its demise yet.

Every day worlds are lost and millions die as the universe eats up Man. Communication is impossible, leading to a fragmented and diverse rule. No place has the same laws. The borders shrink constantly. The light of the Astronomican grows dim, the reach of Man lessens. No central military force with unified national command exists.

And suddenly I realize that the Imperium in my imagination has a lot in common with fourth century Rome.. Now they just need to invite in the Tau to act as military force protecting human worlds in some exposed segments.

Mister Zipangu said:

You're taking dystopia to a whole new level. I feel sad just reading it :-/ and I generally like to laugh at the gritty world of 40k.

No nooo! Lies! The Imperium of Man exists because contemplatingt it's non-existence would be Heresy!

This remind me of a similar situation when playing Star Wars d20. While fighting a space battle one of the players with some physics knowledge (well, a PhD) noted that since there is almost no drag on momentum in space there is no reason why a spaceship travelling at speed x would slow down or stop if hit and disabled by a Laser blast, or if someone was catapulted into space as his ship blows up, thus if said ship was travelling at top speed it would be impossible for other ships to catch up and rescue the survivors. The GM remarked that this would make the game fall apart as suspension of disbelief failed utterly, that our characters would all die and the world would implode due ito it's sheer impossibility.

That quickly stopped the argument and we moved on with our fantasy Science-FICTION RPG....

Friend of the Dork said:

That player either doesn't have as much physics knowledge as you think,his was intentionally holding stuff back. Sure, there is nothing to slow the ejected survivor down, but what matters most for catching up to someone is who has the better acceleration. Beat their acceleration and, unless you run out of fuel, you will catch up with them. The survivor has an acceleration of 0.

Then I'd point out that Star Wars is a setting where trips across the entire galaxy take a week at most,they have enough accuracy to out in orbit of their destination planet. A short hyperdrive jump to get ahead of the survivor is simple.

Bilateralrope said:

Stuff like cosmic dust etc would even decelerate him, at least to a miniscule degree. The faster you go, the higher the resistance. Space is not as empty as some may believe.

Bilateralrope said:

Well, it depends when/where exactly the ship gets disabled. If it happens in normal space, even the fastest ship still takes an eternity to travel to the next system. If it happens in hyperspace, however, it is entirely possible that the ship may get lost somewhere, never to be seen again (there are a couple "ghost ship" stories in the canon about this very topic). The only way to catch up with such a ship would be scanning the wake rotation and the expansion of cronau radiation at the ship's jump point to determine its likely course,then create an interdiction field in its path (ideally by using a gravity well generator, but a big asteroid will do as well) to pull it back into realspace. To get there you can either use a faster hyperdrivecontact someone who is closer. Then have the pursueing ship use a tractor beam on the target vessel to slow down its sublight speed until it stops.

That said, this is all presuming an interface malfunction in the engines preventing the crew from shutting it down. If the hyperdrive itself gets disabled mid-flight, the ship will simply fall back into normal space - if the crew is lucky it'll just be a very bumpy ride, though the drive coils are just as likely to explode from the stress, all depending on how the engines can still handle the deceleration. Hyperdrive failure within hyperspace is usually catastrophic. Which is why most ships are equipped with (much slower) backup engines that automatically spring to action as soon as they detect a power drop in the primary array.

And yes, I've been a huge nerd about Star Wars tech at some time.

To get back on topic, though, I think Mister Zipangu nailed it - although I still see many chances for some sort of "rejuvenation", all depending on if the Imperium manages to survive a reformation, or if maybe the Emperor (or someone who is truly accepted as a real successor) DOES come back at some time in the future (which might likely result in the same thing as option 1) ...

Lynata said:

For the poor survivors sake I really hope he does not hit even the dust... A grain of sand floating free in the space hitting the ejected passenger travelling several thousands of kilometers per hour would pretty much go straight through the passenger without much decelerating him. It would, however, make a hole in space suita far bigger temporary wound cavity in his body. Even though the hole in the suit is no larger than the grain of sand was due to the elasticityhigh water content of the human body the temporary wound cavity can be several dozen times the diameter of the grain of sand...

But aside from physics and into the original question: I don't really think the Imperium is so unrealistic as a concept. We are used to data travelling at light speed and material travelling at airplane speeds on our Earth. We easily think that without electronic communication and airplane speed delivery everything becomes just impossible... Which is not so. 16th, 17th18th century colonial empires existed hundreds of years on Earth worked quite fine even though combination of the ships and land travel took months, sometimes years to get mail, men and material from the capital city to the farthest corners of the empire. Many time small colonies had been out of contact with everyone else for years. No mail, no material, nothing. When the europeans started to colonize American continent dozens of colonies were created and destroyed without ever being in any contact with their home country after the ship left the port in Europe. Ramp this up to the scale where you replace a colonial villages of few hundred people with whole planets and you get Imperium as it is in 40K.

Tharkas Moryn said:

From where do you get this?

Perhaps you are thinking of the fact that the standard year is divided into segments of 1000, each resulting in a 8,76 hour long segment? This does not make these 1000ths of a year into "days" though.

Unless I've missed something?

It's mentioned that the adminstratum uses the year segments (the term for those 1000 units), most people just use whatever is convenient, if it is local days, work shift patterns, watch rotation applied to terran standard day (as in the Imperial Navy, I think).

It is all about decentralisation. it makes sense as long as you realise that every part of the imperium is capable of controlling and ruling itself to a certain degree. How long do you think it took to march armies from say Gaul (France) to Egypt? but the Romans managed to hold together because they made it so that all the parts of its empire ruled themselves when it came to local matters.

The real mystery is that given the sheer scale of the Galaxy... How is it that every time space marines show up, It's almost always the ultramarines... I swear they are EVERYWHERE