Probably I am too late, but, anyway, I have been thinking on the topic and even have an article under review where the idea is mentioned.
My idea is that alien supercivilization could use Dyson spheres to make a drawing on the galactic plane. The drawing is stable and the Dyson spheres are its pixels. Given that typical galaxy has 100 billion of stars, the drawing could be used to send large amount of data on billion of light years (most likely it will be description of an AI, I think).
Yes, there are some difficulties, as galactic rotation, limited speed of light and non-perpendicular angle of the galactic observation, but supercivilization could find the ways to overcome them. One is that the drawing could have two levels: the beacon, which attracts attention, like simple, clear artificial geometric figure, and the second level which provide data in form of smaller drawings.
Probably I am too late, but, anyway, I have been thinking on the topic and even have an article under review where the idea is mentioned.
My idea is that alien supercivilization could use Dyson spheres to make a drawing on the galactic plane. The drawing is stable and the Dyson spheres are its pixels. Given that typical galaxy has 100 billion of stars, the drawing could be used to send large amount of data on billion of light years (most likely it will be description of an AI, I think).
Yes, there are some difficulties, as galactic rotation, limited speed of light and non-perpendicular angle of the galactic observation, but supercivilization could find the ways to overcome them. One is that the drawing could have two levels: the beacon, which attracts attention, like simple, clear artificial geometric figure, and the second level which provide data in form of smaller drawings.