PBS has a youtube channel called Space Time, and here we are presented with a variety of space themed short talks. In this episode; everyone has their own opinion as to whether or not aliens exist. But let’s assume they do for a second and we wanted to let them know we’re here!!!! How should we signal our species’ existence through the expanse of space? There are a few options, but which is the most effective and the cheapest? Find out in this week’s episode of PBS Space Time!