A 400-foot experimental airship called Pathfinder 1, developed by a US-based startup backed by Google Co-founder Sergey Brin, was spotted hovering over San Francisco's skies on Tuesday, when Google released Gemini 3 model. Pathfinder 1 has 12 electric motors, a carbon fibre and titanium frame and is the world's largest aircraft. Inference.net CEO Sam Hogan called it "big baller energy".