How do you prove to someone that you actually touched grass? I guess the bigger question is out of everything going on how is "if i touched grass" still the biggest argument we are having? No more. (Argument, not going outside (well maybe)). Proof of Grass listens to a few seconds of audio with Perch 2.0, an open bird-sound model that runs offline on your laptop. If it hears something alive, you get a receipt chained to the last one, so you can’t edit your history later. I tested it on 560...