Will civilizations want to make contact with others?
Pro:
Con:
It is possible that inter-civilization communications will provide
shared information which will boost the survival rate and increase L.
The number of civilizations that exist is closely related to the mean distance between neighbors (and number of exchanged messages). If, for example, L = 100,000 years, then the average distance between neighbors will be 650 light years and they could exchange about 100 messages before one of them vanishes (see Fig. 18.4 on page 457).