Iain M. Banks's Culture has the ability to travel faster than light (up to 233,000 c) with infraspace engines built from exotic nanomatter, but can it also transmit communication supraluminally?

Edit to be clearer: I realize that they can communicate by messengers/couriers, but what I want to know is if they can transmit massless data, such as electromagnetic waves or indeed light, faster than light. Due to the nature of their physical hyperdrives that can move matter faster than light, it's not clear that they can do the same with something without mass, or even if they can propel mass that doesn't have its own drive attached to it.

  • 6
    If you can travel faster then light, you can transmit information faster then light.
    – Pieter B
    Commented Feb 28, 2017 at 15:47
  • 2
    @PieterB There are fictional universes where FTL communication is performed by couriering messages as there is no non-material FTL signalling, so the question could be reasonable ... except that most of the stories and all of the novels in Bank's setting have multiple instances of FTL comms mentioned rather explicitly in the text. Commented Feb 28, 2017 at 16:15
  • @PieterB Sure, with a messenger. I mean transmission of beams or something else that is logistically cheaper than sending a GSV around the galaxy for each message. Due to the nature of the ships' infraspace/ultraspace drives it's not clear how just data can be transmitted through infraspace. As the answer states, though, it can, somehow.
    – tobiasvl
    Commented Feb 28, 2017 at 16:41
  • 1
    @PieterB Edited in a clarification.
    – tobiasvl
    Commented Feb 28, 2017 at 17:33

3 Answers 3


Yes, although the speed of communication is ill-defined it appears to be very fast indeed, many multiples the speed of light and capable of being sent ahead of ships moving at very rapid velocities.

There's a good, if somewhat flowery, analogy provided in Surface Detail

The only reality-based restriction the galactic house modelled accurately was that produced by the deeply annoying fact that even hyperspacial light did not travel with infinite speed. To carry on a normal conversation with another Mind, one had to be in the same room and reasonably close to it. Even two Minds being within the same vast room but on opposite sides created a noticeable delay as they shouted back and forth.

Being any further away meant sending messages. These usually showed up as gently glowing symbols flickering disembodied in the air in front of the recipient, but – subject to the witheringly prodigious imaginations of Minds in general and the particular and quite possibly highly eccentric predilections of the sender in particular – could show up as almost anything. Swift-moving ballets consisting of multiply-limbed aliens, on fire and throwing shapes which just happened briefly to resemble Marain symbols (for example) were by no means unknown.

  • 2
    Thanks, I'll accept this one for the time being as it has a quote!
    – tobiasvl
    Commented Feb 28, 2017 at 16:42

Yes. For example in Excession, the Minds hold conversations over interstellar distances, with no mention of a significant time lag.

  • 5
    Note though that the fact that these are presented as individual messages, rather than true conversations, implies that they are not instantaneous. Commented Feb 28, 2017 at 11:55
  • 2
    @DanielRoseman - Yes indeed. It's not an ansible.
    – Valorum
    Commented Feb 28, 2017 at 12:13
  • @DanielRoseman Does your comment imply that the answer is wrong? Is the conversation in Excession an example of FTL communication, or is this not stated outright? It's not clear to me what you mean. FTL communication doesn't need to be instantaneous unless it's based on quantum entaglement.
    – tobiasvl
    Commented Feb 28, 2017 at 12:34
  • 1
    No not at all, I was just clarifying. Clearly RCB is correct; the conversations happen over timescales of minutes or hours, rather than hundreds of years as would be expected if they were not FTL. They're just not instantaneous. Commented Feb 28, 2017 at 12:36
  • 3
    @DanielRoseman in Excession they are implied to be instantaneous and a conversation, as in ione example, one Mind is cut out of a group conversation mid-sentence and all other group members react to that.
    – Moo
    Commented Feb 28, 2017 at 16:54


...Or no, depending on how you define lightspeed.

Ian M Banks describes the Minds as

sophisticated AIs working largely in hyperspace to take advantage of the higher lightspeed there

as part of a short article on the Culture.

So the Culture can communicate faster than normal lightspeed, but not faster than hyperspace lightspeed.

  • Aaaaah, this explains a lot, actually.
    – tobiasvl
    Commented Feb 28, 2017 at 21:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.