From references only from the 1982 Blade Runner movie and Do Androids Dream Of Electric Sheep? is there any indication how the science works to reach the "off-world colonies"? Especially for colonies that aren't in the solar system?
(Eg Wormholes, Jump drives, Generation ships...)
It seems that film and book might have different interpretations of this.
I really don't remember the book that well, so what do we know about the film interpretation related to off-world travel and distances?
All quotes taken from the Blade Runner script.
Bryant: There was an escape from the off-world colonies two weeks ago. Six replicants, three male, three female. They slaughtered twenty-three people and jumped a shuttle. An aerial patrol spotted the ship off the coast. No crew, no sight of them. Three nights ago they tried to break into Tyrell Corporation.
So, at most the travel from colony to Earth took 11 days; more likely less, since we would presume replicants had to take some time to orient themselves.
If we are talking sub-light speeds of anything compared to our current capabilities, this wouldn't work for even the planet that is closest to Earth at some time: Venus -- Universe Today lists the fastest journey so far to have taken 110 days.
So, we are talking either at least 10x+ faster sub-light speeds than currently possible, or generation ships or some sort of hyperjumps.
Bryant: The designers reckoned that after a few years they might develop their own emotional responses. You know, hate, love, fear, anger, envy. So they built in a fail-safe device.
Deckard: Which is what?
Bryant: Four year life span.
This one means that these are not generation ships, unless we're talking cryogenic freezing or something similar, or replicants would not arrive at colonies at all. Also, you don't need a generation ship for a travel of 11 days either.
This part is subject to quite some interpretation, however, there are some things which seem logical to me.
As noted in one of the previous answers, Roy Batty's "Tears in the rain" monologue includes references to events he himself witnessed apparently near Orion. Orion nebula is approximately 1,344 light-years distance from Earth. Alternatively, he could be talking about Orion constellation, which would also make sense, as Orion is a hunter in Greek mythology and therefore his constellation would naturally have a "shoulder". It doesn't change the underlying idea, however, since even the closest star in the Orion constellation is more than 200 light-years away.
If we accept Roy's monologue that way, it means that during his near 4 years of life he has managed to get somewhere near the Orion nebula/constellation. It is possible that he was posted there and later on got back near Earth, however, at any rate the implication would be that there is some sort of FTL travel in BR universe, at least in the film version.
As I mentioned in a comment, I have always assumed that the Tannhäuser Gate mentioned by Roy in the same monologue is some sort of warp gate or similar. This view is apparently shared by other viewers up to the point that it is mentioned in BR fandom wiki entry.
As a coherent alternative, if we assume Roy was speaking of seeing attack ships that appeared to be "off the shoulder of Orion", it might mean that he simply saw the ship on the background of Orion nebula or constellation. I am not aware how good would either look from any Solar system planet, but assuming Orion nebula could look impressive from any of them, we could assume that off-world colonies are (at closest), for example, just Mars and/or Venus, and the 11-day travel is simply ~10-20x faster rockets.
This would tie in better with the book, which speaks of colony on Mars etc, as written in another answer. And we presume script writers read the book after all. In that case you could argue that book talks about sub-light travel speeds in all cases. The journey to Proxima Centauri, which is mentioned in the book as described in @Nicola Talbot's answer and which @anaximander calculated as done at around 0.1-0.2c would fit as well, leaving slower speeds for inner system travels (probably because of not enough space/time for acceleration to 0.1c between Earth and Solar system planets).
The only manned space vessel that I can find in the novel is in some dialogue (bold added):
‘The issue is not the legality of the bone marrow analysis,’ Eldon Rosen said huskily. ‘The issue is that your empathy delineation test failed in response to my niece. I can explain why she scored as an android might. Rachael grew up aboard Salader 3. She was born on it; she spent fourteen of her eighteen years living off its tape library and what the nine other crew members, all adults, knew about Earth. Then, as you know, the ship turned back a sixth of the way to Proxima. Otherwise Rachael would never have seen Earth — anyhow not until her later life.’
Do Androids Dream of Electric Sheep? Chapter 5.
So it seems that ships were used. Not quite generational if Rachael (had she genuinely been on the Salader 3) could have reached Proxima and then returned to Earth later in life, but the journey obviously takes years.
The only other space vessel that's mentioned is an autorocket, which appears to be unmanned and is used by smugglers (bold added):
‘It’s worthless, here, because here on Earth the craze never caught on. Anyhow there’s plenty here, in the libraries; that’s where we get all of ours — stolen from libraries here on Earth and shot by autorocket to Mars. You’re out at night bumbling across the open space, and all of a sudden you see a flare, and there’s a rocket, cracked open, with old pre-colonial fiction magazines spilling out everywhere. A fortune. But of course you read them before you sell them.’ She warmed to her topic. ‘Of all —’
Do Androids Dream of Electric Sheep? Chapter 13.
Other references to space travel are vague, just ‘the ship’ without any technical details.
I think @ruakh's comment is correct:
but if this was a ten-person ship to travel 4.3 light-years then it's probably not representative of how most people travel. (Perhaps Saladar 3 was supposed to install something there that would enable FTL travel?)
The first quote above about the Salader 3 bound for Proxima (presumably the system around Proxima Centauri, the closest star to us outside our solar system), is the only mention of a location outside of our solar system, so it could well be that the Salader 3's trip was the first attempt to leave the solar system (which makes its failure memorable). The only off-world colony that's actually mentioned is Mars: Roy Baty, Pris etc are from Mars, and there's a TV interview with a woman who emigrated to Mars:
‘Let’s hear from Mrs Maggie Klugman,’ the TV announcer suggested to John Isadore, who wanted only to know the time. ‘A recent immigrant to Mars, Mrs Klugman in a[n] interview taped live in New New York had this to say. Mrs Klugman, how would you contrast your life back on contaminated Earth with your new life here in a world rich with every imaginable possibility?’ A pause, and then a tired, dry, middle-aged, female voice said, ‘I think what I and my family of three noticed most was the dignity.’ ‘The dignity, Mrs Klugman?’ the announcer asker. ‘Yes,’ Mrs Klugman, now of New New York, Mars, said. ‘It's a hard thing to explain. Having a servant you can depend on in these troubled times... I find it reassuring.’
‘Back on Earth, Mrs Klugman, in the old days, did you also worry about finding yourself classified, ahem, as a special?’
‘Oh, my husband and myself worried ourselves nearly to death. Of course, once we emigrated that worry vanished, fortunately forever.’
Do Androids Dream of Electric Sheep? Chapter 2.
If Mars is the only off-world colony at the time when the story is set (with Proxima the next target for exploration) then the journey is feasible with our modern real-life technology.
Just in case the comments disappear, I'm copying @anaximander's calculations here:
If Salader 3 flew one-sixth of the 4.3ly to Proxima, turned round, and flew back, and that took 14 years, then that averages out at approximately 0.1c (disregarding time dilation). Assuming a roughly straight-line brachistochrone trajectory, under acceleration at all times, then that's somewhere around 0.14*g* acceleration to 0.2c after 3.5 years, then 3.5 years to slow down and "stop", 3.5 years to get back to 0.2c heading Earthward, and 3.5 years to slow down and stop back at Earth. That's all pretty approximate, but as a ballpark it's all fairly reasonable by scifi standards.
Rosen is lying about Rachael but assuming he's basing her backstory on a girl who actually was born on the Salader 3, then that provides realistic upper and lower bounds, depending on whether she was born at the start of the journey or just before it turned back.
I disagree with the source used in wcullen's answer saying:
the "central issues [are] left un- or under-explained" including, "Where are the 'off world colonies'?"
Indeed, Mars is mentioned during chapter 2 of Do Androids Dream of Electric Sheep?:
"Let's hear from Mrs. Maggie Klugman," the TV announcer suggested to John Isidore, who wanted only to know the time. "A recent immigrant to Mars, Mrs. Klugman in an interview taped live in New New York had this to say.
As for the jumpships/wormholes etc, there might be a slight indication during Batty's monologue at the end of Blade Runner:
Attack ships on fire off the shoulder of Orion.
So we have attack ships. Why not travel ships as well? Especially considering that Mars isn't that far, for a SF book at least.
There's no indication of how the ships work in either the novel or the film (any iteration).
It shouldn't really be a surprise given that the workings of technology are not the focus of the story at all (e.g. there's little but cursory discussion of how the VK machine actually works or, in the novel, how the genetic disintegration occurs); Rather, how do some technologies challenge and hold a mirror to the question 'what is it to be human'.
Given PKD's skill as a SF writer and thinker, any discussions of details would be a distraction--IMO.
I also don't know of any mention that the off-world colonies are/are not beyond our solar system.
One of the best things about BR/DADOES is that, like any good SciFi, the "central issues [are] left un- or under-explained" (S. Bukatman, Blade Runner, p. 17)--including, "Where are the 'off world colonies'?" (ibid).
The only comment I will make is that if you look at an illustration of the Orion constellation then you will see that the position of the shoulder of Orion is occupied by Betelguese. Betelguese is a Red Giant star about 430 light years from the Solar System. The Tannhauser gate is a warp station in the vicinity of Betelguese. C beams are faster than light beams that push and pull spacecraft through the warp. In a deleted scene of the film Soldier, the battle of and the gate itself was pictured. To travel 430 light years in ten days means that you must travel at a speed of around 43 light years per day. So thats 43 x 365 light years in a year. That's a speed of about 16000 C.
In brief, the 'off-world' travel in the Blade Runner fictional universe is inconsistent, incomprehensible and leaves every question unanswered.
The very short answer is that in the two original films there's essentially no mention of how off-world travel is accomplished.
If we take the comics as canon, we see a star gate in Blade Runner 2019 #6. This appears to be a riff off of Hauer's speech where he mentions something called the "Tannhauser Gate". It has no obvious mechanism and we don't see it working. It merely exists.
Travel to the stargate is undertaken using some form of sublight engine. These have large and visible glowing stacks but no visible exhaust. It's not clear what fuel they're using or the energy source propelling them.
