In the Photosynthesis exhibit, visitors can contemplate several cultures of oxygenic phototrophic bacteria in plastic Petri dishes.
So getting a note from one star system to the next would take more generations than the average human mind can contemplate.
No, there are no rules about this.
It's at times like these when I sit and contemplate and plot.
The Dalai Lama is quite happy to contemplate the karma of digital technology while leaving geeky details to the younger crowd.