Robot explores second shaft, discovers matching door Mon Sep 23,11:40 AM ET By DONNA BRYSON, Associated Press Writer CAIRO, Egypt - Scientists using a robot have discovered yet another door deep inside the Great Pyramid, Egypt's head archaeologist said Monday. Friday's discovery followed the robotic revelation on live, international television Sept. 17 of a chamber behind a similar stone door in another shaft in the pyramid the pharaoh Khufu built more than 4,000 years ago. "This find in the northern shaft, coupled with last week's discovery ... in the southern shaft, represents the first major new information about the Great...