Inspired partially by this comment on one of my answers, I got to thinking on what the quickest way to communicate would be on an intergalactic scale.
Say humans have colonised the galaxy, and use wormholes for faster-than-light travel. How would they communicate with other colonies?
As far as I am aware communications can be done by either radio waves (as done with the Mars Rover for example, and most interplanetary satellites) however this has a delay into the minutes already just one planet over, and would definitely not be fast enough on such a large scale.
You could use light based data transfers (based on optical fibre for example, without the cable) however this would still be restricted to the speed of light, which at such distances is still not as quick as you might hope.
Sending raw light based or radio based data transfers through wormholes would be out of the question, as the signal would be severely scrambled and undecipherable on the other end, if it reached anywhere to begin with.
The only way I could think of would be to send physical carriers, (little spaceships carrying the data) back and forth through wormholes. However that is not ideal as it seems expensive and still not very fast.
Is there any way to achieve near instant intergalactic communications without having to rely on the cosmic variety of carrier pigeons?
Edit: As pointed out by Guy with jewels' names, this much depends on the stability of wormholes in my world. I had not given this much thought, but I always assumed at least the following:
Travel through wormholes is hard and risky. It will bash and tear away at ships, and insufficiently armoured ships will just be torn apart. This significantly reduces longevity of any ships regularly jumping through wormholes.
They would not be stable enough to run a physical cable through. This would (in my opinion) be "too easy". Also you would still need enough cable to span the entire distance.
Wormholes can't be created artificially. They exist naturally, and in large part are a deciding factor on where intergalactic travel is possible. They are however fairly abundant and cover most of the galaxy.