> That would lead me to speculate that if we were looking for messages from the previous universe (in the style of the movie/book Contact) then we should look to the signature of the background radiation (CMB).
That was the premise behind the Stargate Universe TV series.
<spoilers> The Ancients detect a pattern in the cosmic background radiation that hints at an intelligence that existed before the beginning of time and send a fleet of automated ships with FTL to research it. Millions of years later, the US Air Force manages to send a team on a one way trip to the flagship and hijinks ensue.</spoilers>
> But I really wonder - what would be more complex?
> Building interactive programs based on HTML or Logo (if anybody does remember)?
Hold my beer: my Github Actions CI scripts use Logo to generate the bash build scripts as images that are then OCRed and executed by a special terminal that exploits the Turing complete nature of Typescript's type system.