We have Little Chance of Hearing Other Civilizations; APO’s vs Catadioptric Telescopes; Another Black Hole Question

We've been listening for signals from the galaxy hoping to detect another civilization out there. What are the actual chances we'll hear anything? Let's take a look at this paper and find out: https://arxiv.org/pdf/1007.0850.pdf

Dustin and Tony also talk about APO refractors and catadioptric telescope systems.